Tag Archives: CNS

Subacute Encephalopathies (Rapidly Progressive Dementias)

This is a group of conditions that are collected under the term subacute encephalopathy, which is also called rapidly progressive dementias. These conditions manifest with cognitive dysfunction over weeks or months. Therefore the onset and progression is slower than encephalopathy due to systemic disease and faster than usual causes of dementia which progress over years. … Continue reading Subacute Encephalopathies (Rapidly Progressive Dementias)

Non-vasculitic Autoimmune Inflammatory Meningoencephalitis (NAIM)

Clinical features: Progressive encephalopathy, cognitive impairment. Ataxia, seizures, tremors and visual hallucinations can occur. Findings on investigations: ESR may be raised SS-A or SS-B: may be positive CSF analysis: Often raised WCC and protein Immunoglobulin (Ig)G index and synthesis rate EEG: mild-moderate diffuse slowing MRI: normal Cerebral angiography: normal Pathology, brain biopsy: Leptomeningeal perivascular lymphocytic … Continue reading Non-vasculitic Autoimmune Inflammatory Meningoencephalitis (NAIM)

Glucose Transporter Type I Deficiency Syndrome GLUT1 DS

Clinical features: Seizures, developmental delay, spasticity, acquired microcephaly, and ataxia Dystonia Genetics: Autosomal dominant, de novo mutation SLC2A1 gene, Findings on investigations: CSF: low glucose, low glucose:serum ratio, low CSF lactate Erythrocyte glucose transporter activity: reduced uptake into erythrocytes Related articles: Approach to movement disorders, approach to ataxia, approach to dystonia, Epilepsy,

Niemann-Pick Disease

Diagnosis: A type of lysosomal storage disease Biochemical diagnosis: Fibroblast culture to test for impaired LDL-cholesterol trafficking. Filipin staining: accumulated free cholesterol. Impaired LDL-induced cholesterol ester formation. A variant biochemical form exists Genetics: Autosomal recessive Niemann-Pick disease type C: gene= NPC1 at 18q11 or NPC2 14q Clinical features: Type A: Infantile, severe, cherry red macula, … Continue reading Niemann-Pick Disease

Cerebrotendinous Xanthomatosis

Clinical features: Neonates: cataracts, diarrhea, pyramidal and cerebellar signs, learning disability later on Adults: Seizures, dementia, myelopathy (spinal form), Enlarged tongue, tendon xanthomas, premature vascular disease, cataracts Genetics: Autosomal recessive, CYP27A1 gene on chromosome 2q, sterol 27-hydroxylase deficiency, Findings on investigations: Lipid profile: increased cholesterol CT: white matter hypdensities in cerebrum, cerebellar dentate nucleus hypdensities, … Continue reading Cerebrotendinous Xanthomatosis

Refsum Disease

A type of leukodystrophy. A type of peroxisome disorder. Synonyms: a.k.a. hereditary ataxic neuropathy a.k.a. phytanic acid storage disease a.k.a. hereditary motor sensory neuropathy type IV a.k.a. heredopathia atactica polyneuritiformis Clinical features: Deafness, ataxia, anosmia Retinitis pigmentosa (night blindness) Progressive peripheral neuropathy Ichthyosis: dry scaly skin Cardiac arrhythmias Short metacarpals and metatarsals Findings on investigations: … Continue reading Refsum Disease

Zellweger Syndrome

Synonyms: a.k.a. cerebro-hepato-renal syndrome Diagnosis: A type of Leukodystrophy and peroxisome biogenesis disorders (PBD) Confirmed by Serum very long chain fatty acids: elevated Genetics: PEX3 gene mutations Clinical features: Severe weakness, hypotonia, seizures and developmental delay high forehead, underdeveloped eyebrow ridges, deformed earlobes Hepatomegaly Facial features: high forehead, hypoplastic supraorbital ridges, and midface hypoplasia. A … Continue reading Zellweger Syndrome

Megalencephalic Leukodystrophy with Subcortical Cysts

Diagnosis: A type of leukodystrophy Genetics: MLC1 gene mutation Clinical features: Large head circumference Findings on investigations: MRI: subcortical cysts in the frontal and temporal poles Related articles: White matter diseases, Leukodystrophies,

Vanishing White Matter disease VWM

Synonyms: a.k.a. leukoencephalopathy with vanishing white matter a.k.a. childhood ataxia and cerebral hypomyelination CACH Diagnosis: A type of leukodystrophy. A type of dysmyelination Genetics: Autosomal recessive Mutations in one of five genes for translation factor (eukaryotic initiation factor 2B, elF2B) on chromosome 3: ELF2B1, ELF2B2, ELF2B3, ELF2B4, ELF2B5 Clinical features: <6 year olds at presentation, … Continue reading Vanishing White Matter disease VWM

Pelizaeus-Merzbacher-Like Disease

A type of leukodystrophy Genetics: heterogeneous Autosomal recessive, Protein= gap junction protein 12 a.k.a. connexin 46.6 (Cx 46.6), a.k.a. connexin 47 (Cx 47), Gene= GJA12 gene mutation Clinical features: First months of life: impaired motor development and nystagmus Later on: ataxia, dystonia, dysarthria, and progressive spasticity Spastic paraplegia: childhood onset, progressive and may occur without … Continue reading Pelizaeus-Merzbacher-Like Disease

Pelizaeus Merzbacher Disease PMD

Diagnosis: A type of leukodystrophy Genetics: X-linked recessive disease, Gene: PLP1 gene, rearrangements or mutations. Protein= proteolipid protein 1 Clinical features: First months of life: impaired motor development and nystagmus Later on: ataxia, dystonia, dysarthria, and progressive spasticity Spastic paraplegia: childhood onset, progressive and may occur without other features Findings on investigations: MRI: hypomyelination pattern, … Continue reading Pelizaeus Merzbacher Disease PMD

Sudanophilic Leukodystrophy

Diagnosis: A type of leukodystorphy. A type of dysmyelination Findings on investigations: Imaging: White matter (hemispheres, cerebellum and brainstem) and grey matter CT: hypodense T2 MRI: hyperintense white matter. Hypointense lentiform nucleus, thalamus, substantia nigra, dentate nucleus Pathology: Sudanophilic material in macrophages. Reduced oligodendrocytes. Tigroid appearance: abnormal white matter background, normal neurons. Subtype: Pelizaeus-Merzbacher disease … Continue reading Sudanophilic Leukodystrophy

Canavan Disease

A type of leukodystrophy. A type of dysmyelination. Synonyms: a.k.a. spongiform degeneration a.k.a. N-acetylaspartatoacylase deficiency Genetics: Autosomal recessive. Gene encoding acetylaspartoacylase. Findings on investigations: Imaging: Deep grey matter, subcortical white matter, U fibres, cerebellar, brain stem. Ventriculomegaly/megalencephaly. CT: low density T2 MRI: hyperintense MRS magnetic resonance spectroscopy: Raised NAA Pathology: Vacuolation of white matter. Gliosis. … Continue reading Canavan Disease

Alexander Disease

Diagnosis: A type of leukodystrophy a.k.a. dysmyelination. A type of intermediate filament disease. Genetics: Sporadic. GFAP gene mutation. Encoding Glial fibrillary acidic protein. Findings on investigations: Imaging: Cerebral white matter lesions frontal >occipital. Brain stem atrophy CT: hypodense white matter diffusely. Hyperdense caudate. T1: hypodense white matter. T2: hyperintense white matter Enhancement early in disease … Continue reading Alexander Disease

Adrenoleukodystrophy and Adrenomyeloneuropathy

Diagnosis: Very long chain fatty acids VLCFAs: raised C26:0 level, raised C26:0/C22:0 ratio, raised C24:0/C20:0 ratio. This is diagnostic. Genetic tests usually follow. A type of peroxysomal disease. A type of leukodystrophy a.k.a. dysmyelination Genetics: X-linked or Autosomal recessive (neonatal) ALD gene a.k.a. X-linked adrenoleukodystrophy gene chr. Xq28, encoding perioxysomal ATP binding cassette half-transporter protein … Continue reading Adrenoleukodystrophy and Adrenomyeloneuropathy

Krabbe Disease (Globoid Cell Leukodystrophy)

Synonyms: a.k.a. galactocerebroside b-galactosidase deficiency Diagnosis: Assay of beta galatosylcerebrosidase activity is diagnostic. A type of leukodystrophy. A type of dysmyelination. Pathogenesis: Oligodendrocyte apoptosis and gliosis Clinical features: Clinical: Progressive cognitive decline, seizures, and cortical blindness. Peripheral weakness. Peripheral neuropathy demyelinating pattern, up to 60% of patients, may be asymmetric, Genetics: Autosomal recessive Findings on … Continue reading Krabbe Disease (Globoid Cell Leukodystrophy)

Metachromatic Leukodystrophy MLD

Synonyms: a.k.a. arylsulfatase A deficiency Diagnosis: A type of leukodystrophy a.k.a. dysmyelination Enzyme activity: Reduced arylsufatase A deficiency Test leukocytes Urine: sulfatide accumulation Clinical features: Peripheral neuropathy Findings on investigations: Electrophysiology: Demyelinating sensorimotor Peripheral neuropathy Imaging: Symmetrical demyelination, corpus callosum, centrum semiovale, cerebellum, spares the cortical U fibres. Multifocal frontal lobe lesions can occur. Atrophy, … Continue reading Metachromatic Leukodystrophy MLD


Synonyms: Leucodystrophy, leukodystrophies Introduction: This is a group of various disorders of abnormal white matter myelination. They are often referred to as dysmyelinating disorders. Types: Adrenoleukodystrophy and adrenomyeloneuropathy Metachromatic leukodystrophy MLD a.k.a. arylsulfatase A deficiency Krabbe disease (Globoid Cell Leukodystrophy) a.k.a. galactocerebroside b-galactosidase deficiency Alexander disease Canavan disease a.k.a. spongiform degeneration a.k.a. N-acetylaspartatoacylase deficiency Sudanophilic … Continue reading Leukodystrophy

Bilateral Striatal Necrosis

Clinical features: Gradual progressive generalised dystonia, choreoathetosis, febrile illness, Genetics: Mitochondrial DNA: ND6 gene, T1487C mutation, Findings on investigations: Respiratory chain analysis: decreased activity of complex 1 Related articles: Mitochondrial disorders,

Leigh’s disease (Subacute necrotizing encephalomyelopathy)

Synonyms: Leigh’s disease a.k.a. Subacute necrotizing encephalomyelopathy Clinical features: 3 months- 2 years of age, poor suck, loss of head control, seizures, cardiac problems Genetics: Mutations in the mitochondrial DNA or deficiencies of pyruvate dehydrogenase Findings on investigations: MRI: symmetric hyperintensity in periaqueductal area, midbrain tectum, caudate, putamen, globus pallidus, substantia nigra. Spares mammillary bodies … Continue reading Leigh’s disease (Subacute necrotizing encephalomyelopathy)

Mitochondrial Neurogastrointestinal Encephalomyopathy MNGIE

Synonyms: a.k.a. MINGE, rare Diagnosis: Genetic analysis Genetics: POLG gene or Thymidine phosphorylase (TP) mutation TP mutation: Autosomal recessive Mitochondrial DNA (mtDNA) analysis: depletion, deletions, and point mutation Clinical features: External ophthalmoplegia, gastrointestinal dysmotility (dysphagia and intestinal pseudoobstruction) and pain, cachexia, peripheral neuropathy, encephalopathy Findings on investigations: MRI: leukoencephalopathy Muscle biopsy: ragged red fibres Treatment: … Continue reading Mitochondrial Neurogastrointestinal Encephalomyopathy MNGIE

Alper Syndrome

Synonyms: a.k.a. Alper-Huttenlocher syndrome a.k.a. progressive infantile poliodystrophy Diagnosis: POLG gene (polymerase gamma), nuclear DNA mutation analysis Genetics: POLG gene (polymerase gamma), nuclear DNA mutation Secondary findings, Mitochondrial DNA (mtDNA) analysis: depletion, deletions, and point mutations Clinical features: Status epilepticus, abnormal liver enzymes, axonal neuropathy, Findings on investigations: CSF lactate: increased CSF: may show an … Continue reading Alper Syndrome

Kearns-Sayre Syndrome KSS

Clinical features: Onset before 20 years of age. Progressive external opthalmoplegia (restricted eye movements, usually movements are not dysconjugated) and pigmentory retinopathy. Also myopathy, heart block, CNS deficits, short stature. Pathology: Muscle biopsy: Gomori trichrome: Ragged red fibres Variation in muscle size COX negative fibres Brainstem and cerebellum: neuronal loss. Spongy to vacuolar myelinopathy. May … Continue reading Kearns-Sayre Syndrome KSS

Mitochondrial Disorders

There are many diseases that are included in mitochondrial disorders. They often share common features. Synonyms: a.k.a. mitochondrial cytopathies, mitochondrial neurological disorders Subtypes of mitochondrial disorders: Alper syndrome a.k.a. Alper-Huttenlocher syndrome a.k.a. progressive infantile poliodystrophy Kearns-Sayre Syndrome KSS Mitochondrial encephalomyopathy lactic acidosis and stroke MELAS Myoclonic epilepsy and ragged red fibres MERRF Mitochondrial neurogastrointestinal encephalomyopathy … Continue reading Mitochondrial Disorders

Autonomic Neuropathy

Synonyms: Autonomic neuropathy/autonomic failure/autonomic dysfunction Diagnosis: Autonomic dysfunction may be central (CNS) or peripheral (PNS) Clinical features: Helps define distribution and extent of disease: Sympathetic, parasympathetic Adrenergic, cholinergic Helps define presents of associated CNS disease Helps define associated systemic disease Autonomic function testing: Baroreceptor function testing a.k.a. Cardiovagal testing by HR variability: Beat to beat … Continue reading Autonomic Neuropathy


Tremor is a neurological symptom and a neurological sign. It can be due to primary disorders of the nervous system or secondary nervous system dysfunction due to systemic disease. Tremors can also be physiologic and certain substances such a caffeine or circumstances such as anxiety can exaggerate physiological tremors.   Clinical features: Involuntary, rhythmic, alternating, … Continue reading Tremor

Primary Lateral Sclerosis

Diagnosis: Clinical features plus unrevealing investigations (NCS/EMG, MRI, lab tests) for other causes. This  is a diagnosis of exclusion.   Diagnostic categories of PLS (Gordon et al.) Autopsy-proven PLS Clinically diagnosed PLS with degeneration in motor cortex and corticospinal tracts, no loss of motor neurons, no gliosis in anterior horn cells, and no Bunina bodies … Continue reading Primary Lateral Sclerosis


Diagnosis: MRI: Smooth surface of the brain Genetics: Doublecortin (DCX) gene, X-linked. Blood testing available. MRI in affected men: lissencephaly MRI in affected women: double cortex band heterotopia, subcortical laminar heterotopia, lissencephaly Related articles: Epilepsy,


Diagnosis: MRI: near total absence of cerebral cortex and basal ganglia. Thalami, pons, cerebral peduncles, cerebellum are present. Parts of frontal, temporal, occipital lobe may be present. i.e. loss of structures supplied by the internal carotid arteries.

Behcet's Syndrome

Diagnosis: Recurrent oral ulceration plus two of the following: Recurrent genital ulceration Eye lesions Skin lesions Pathergy test: skin reaction to intradermal saline injection Findings on Investigations: MRI brain: Infarcts: brainstem and thalamic Cerebral Angiogram/angiography: Narrowing, aneurysm (arterial and venous) Investigations to consider: ESR and CRP: Raised FBC: leukocytosis Treatment: Mucous membrane involvement: Glucocorticoid mouthwash … Continue reading Behcet's Syndrome

Takayasu’s Disease

Synonyms: a.k.a. aortic arch syndrome a.k.a. Takayasu’s arteritis: Diagnosis: Arteriography: Irregular vessel walls, stenosis, poststenotic dilation, aneurysms, occlusion, collaterals Usually smooth stenosis of the common carotid and the subclavian arteries Other imaging: Ultrasound: thickened intima layer CT: thickened enhancing walls MRA Treatment: Control the symptoms and inflammation before surgery: Prednisolone, Correct the anatomical defects: Angioplasty … Continue reading Takayasu’s Disease

Neurosarcoidosis, Sarcoid disease Neurological Manifestations

Neurosarcoidosis manifestations: Myelopathy Cranial neuropathies Pituitary disease Dural based lesion Encephalopathy CNS sarcoid angiitis Peripheral sensory neuropathy Myopathy Diagnosis: Histology: +typical findings +excluding other diseases confirms the diagnosis Histology: noncaseating granuloma Findings on Investigations: CXR: Stage 0: normal Stage I: bilateral hilar lymphadenopathy or paratracheal lymphadenopathy Stage II: hilar lymphadenopathy +pulmonary infiltrates Stage III: pulmonary … Continue reading Neurosarcoidosis, Sarcoid disease Neurological Manifestations

Febrile Seizures

Diagnosis: Seizures associated with fever in children from 6 months to 6 years old Complicated febrile seizure: >15 minutes, recur within 24 hours, localising signs i.e. complex febrile seizures, multiple seizures These need more evaluation and observation Investigations to consider: FBC, U&E, glucose Blood cultures Urinalysis +/-urine culture CSF analysis Consider EEG and MRI Treatment: … Continue reading Febrile Seizures

Tuberous Sclerosis

Synonyms: a.k.a. Bournvile disease Genetics: Genetic tests: chr. 9q34 TSC1 encoding hamartin , chr. 16p13 TSC2 encoding tuberin Diagnosis: Clinical features plus findings on investigations Clinical  features: Seizures Retinal hamartomas Skin: Hypopigmented macules a.k.a. ‘Ash leaf shaped’, easier to see with Wood lamp (UV light)= poliosis (white hair) on the scalp Ungal fibromas, shagreen patches … Continue reading Tuberous Sclerosis

Encephalofacial Angiomatosis, Sturge-Weber disease

Diagnosis: A combination of clinical findings and imaging Clinical features: Skin: Facial nevus ‘port wine stain’ ‘nevus flammeus’, may be absent. In the distribution of trigeminal nerve Eye: Congenital glaucoma, bupthalmus, cloudy enlarged cornea Findings on Investigations: CT: Calcification of the cortex Cortical atrophy MRI: Venous hemangioma of the meninges in the occiptal region. Underlying … Continue reading Encephalofacial Angiomatosis, Sturge-Weber disease

Familial Hyperekplexia

Synonyms: a.k.a. Familial startle disease Diagnosis: This is a clinical diagnosis Genetics: Autosomal dominant, autosomal recessive (frame shift) Glycine Receptor alpha subunit GLRA1 5q32 Clinical features: Infants: stiff (except when sleeping), excessive startle response Older patients: Sudden myoclonus or falling Spastic paraparesis in one family Precipitated by sudden stimuli Treatment: Responds to benzodiazepines Related articles: … Continue reading Familial Hyperekplexia

Tongue-Neck Syndrome

Clinical features: Pain in the neck/occiput and ipsilateral half of the tongue symptoms (numbness, paraesthesia, pseudoathetosis, dysarthria) aggravated by neck movement, Investigations to consider: MRI c-spine: cervical spondylosis Related articles: Myelopathy,

Isolated Facial palsy, CN VII

Upper motor neuron lesion: Diagnosis: This is a clinical diagnosis. The underlying cause is determined by investigations and clinical correlation. Clinical features: Sparing of the forehead muscles Asymmetry of face at rest or on movement: smile, puffing the cheeks and on wincing The palpebral fissure may be widened on the affected side Investigations to consider: … Continue reading Isolated Facial palsy, CN VII

Parinaud Syndrome

Synonyms: Sylvian acqueduct syndrome a.k.a. Koeber-Salus-Elschnig syndrome Diagnosis: This syndrome is a clinical diagnosis. The underlying cause is determined by investigations and clinical correlation. Clinical features: Slightly dilated fixed pupils (i.e. no light reflex), light-near dissociation, upward gaze palsy. Lid retraction (Collier’s sign) Convergence-retraction nystagmus (especially on attempted up gaze) Investigations to consider: MRI: Lesion … Continue reading Parinaud Syndrome

Acquired Oculomotor Apraxia

Synonyms: a.k.a. Roth-Bielschowsky syndrome (supranuclear palsy of gaze due to corticotectal/corticotegmental tract lesions) Diagnosis: A form of supranuclear palsy diagnosed clinically and by isolating the underlying cause Clinical features: Inability to perform horizontal saccades Vertical eye movements may be intact Oculocephalic reflexes are intact Caloric testing shows slow deviation without saccades Optokinetic nystagmus remains without … Continue reading Acquired Oculomotor Apraxia

Cavernous Sinus Syndrome

Diagnosis: This is a clinical diagnosis. Dysfunction of cranial nerves III, IV, and VI, and the superior divisions of cranial nerve V. Investigations to consider: Blood tests: FBC, U&E, fasting Glucose Vasculitic screen, ESR, CRP, ANCA, ANA, ENA SPEP, ACE Tests for infections: Borrelia serology, HIV MRI pre and post contrast: Pituitary tumors, meningioma, metastasis … Continue reading Cavernous Sinus Syndrome

Internuclear Ophthalmoplegia (INO)

Diagnosis: This is a clinical diagnosis. The underlying cause is determined by investigations Clinical features: Diplopia Classic variant, posterior INO: On lateral gaze: Failure of adduction of the contralateral eye, nystagmus of the abducting eye Medial rectus is less weak on testing each eye separately Anterior INO variant: Divergent eyes bilaterally, paralysis of both medial … Continue reading Internuclear Ophthalmoplegia (INO)

Abducens (cranial nerve VI palsy)

Diagnosis: This is a clinical diagnosis Clinical features: Horizontal diplopia In neutral gaze, normal appearance or head is slightly turned to the unaffected side (compensation for unopposed medial rectus) On movement: Affected eye fails to abduct Investigations to consider: Blood tests: ESR: giant cell arteritis TFT, glucose ANCA: Wegner’s granulomatosus HbA1c ESR CT: Out rules … Continue reading Abducens (cranial nerve VI palsy)

Trochlear Nerve Palsy (Cranial IV palsy)

Diagnosis: This is a clinical diagnosis Clinical features: Rare in isolation In neutral gaze: slight head tilted contralateral to the weak superior oblique muscle (loss of in-torsion) Test with eye adducted and moved inferiorly. This is also the position of worse diplopia If bilateral: on horizontal gaze, the abducting eye drifts downwards (inferior rectus of … Continue reading Trochlear Nerve Palsy (Cranial IV palsy)

Oculomotor Palsy (cranial nerve III palsy)

Synonyms: a.k.a. III nerve palsy Diagnosis: This is a clinical diagnosis. The underlying cause requires investigations. Clinical features: In neutral gaze: The eye is looking down & out. There is complete ptosis. On looking downwards torsional (in-torsion) nystagmus of the eye occurs (due to intact IV nerve action) Note the presence of meiosis: Normal pupil … Continue reading Oculomotor Palsy (cranial nerve III palsy)

Horner Syndrome

Synonyms: a.k.a. occulosympathetic defect Diagnosis: This is a clinical diagnosis plus pharmacological tests on occasion Clinical features: Miosis, partial ptosis, anhydrosis, illusion of enophthalmos, red eye Pharmacological test: Cocaine eye drops 2% in both eyes, failure to dilate diagnoses Horner’s syndrome. Dilation on adding amfetamine (Paradrine 1% (hydroxyamphetamine, most common) or Pholedrine 5% (n-methyl derivative … Continue reading Horner Syndrome

Cancer-associated retinopathy (CAR)

Diagnosis: A paraneoplastic syndrome. diagnosed based on clinical features, associated antibodies, perimetry and identification of the underlying neoplasm Clinical features: Rapid visual loss Anti CAR antibodies (VPS, Anti-Recoverin): raised Goldmann perimetry: ring-like scotoma in each eye Investigations to consider: CT chest abdomen & pelvis: lung cancer Related articles: Approach to visual deficits, Optic neuritis,


Diagnosis: This is a clinical finding on examination. The corresponding symptom is oscillopsia, although it is often absent. Nystagmus is common in disorders that cause vertigo or ataxia. Investigations to consider: Down beat, MRI: cervicomedullary lesions, Chiari Malformation, Multiple sclerosis, brainstem tumor, brainstem stroke, spinocerebellar degeneration Convergence-Retraction: MRI: dorsal midbrain lesions Ocular bobbing, MRI: pontine … Continue reading Nystagmus


Diagnosis: This syndrome a clinical diagnosis and has many underlying causes. Clinical features: Uncoordinated or inaccurate movement not due to paresis, sensory disturbances, increased tone or involuntary movements. A combination of any of the following features may occur: Gait: broad based, staggering & swaying, unsteady, Truncal ataxia: inability to sit or stand without support Dysmetria: … Continue reading Ataxia

Chorea, in general

Diagnosis: This is a clinical diagnosis with various underlying causes Clinical features: Involuntary, nonrhythmic, rapid, irregular, jerky, purposeless, unpredictable, non-sustained Investigations to consider: consider as appropriate Tests: for Wilson’s disease Tests: for Huntington’s disease Blood smear: increased acanthocytes (suggests neuroacanthocytosis) Uric acid in young: Lesch-Nyhan disease Related articles: Approach to movement disorders,


Myoclonus, as a symptom of movement disorders: Diagnosis: Clinical: Rapid, brief, involuntary, jerk, muscle contraction (positive myoclonus) or inhibition of tone (negative myoclonus) Myoclonus by EMG: bursts <75 msec is diagnostic Types of myoclonus: By location: Cortical Subcortical: Brain stem (e.g. opsolonus myoclonus syndrome, hemifacial spasm) Spinal Segmental By relation to action: Action Postural Reflex … Continue reading Myoclonus


Diagnosis: Clinical: Involuntary, nonrhythmic, rapid, explosive, purposeless, flinging/flailing movement of upper limb. Often this is triggered by attempt to move. Investigations to consider: MRI +DWI: infarct in subthalamic nucleus Treatment options: Chlorpromazine IV. P.O. Related articles: Approach to movement disorders,

Dystonia, in general

Diagnosis: This is a clinical diagnosis. There are many underlying causes Clinical features: Simultaneous contraction of agonist & antagonist muscles, involuntary, Decide on primary vs. secondary Assess for isolated dystonia or other features e.g. myoclonus, parkinsonism, peripheral neuropathy, etc Consider: EMG in atypical cases EEG: if necessary to distinguish from seizures Investigations to consider: consider … Continue reading Dystonia, in general

Leukoencephalopathy (white matter disease)

Damage to white matter may occur due to may conditions that can affect the brain. The clinical features, prognosis and treatment are related to the underlying condition Clinical features: There is a wide range of symptoms: Rapidly progressive dementia/subacute encephalopathy, lower body parkinsonism/gait apraxia, behavioural changes, pseudobulbar speech and pseudobulbar affect may occur Later on … Continue reading Leukoencephalopathy (white matter disease)

Charles Bonnet Syndrome

Diagnosis: This is a clincial diagnosis Clinical features: Vivid visual hallucinations occurring in healthy people with visual impairments e.g. cataracts. Related articles: Approach to cognitive impairment,

Klüver-Bucy syndrome

Diagnosis: This is a clinical diagnosis Clinical features: Hypersexuality, hyperorality, visual agnosia, and placidity (diminished emotional reactions). Investigations to consider: MRI: Lesions in bilateral medial temporal lobes, e.g. Traumatic brain injury, herpes, other infections Consider tests for dementias (FTLD, Alzheimer’s) & infections Related articles: Traumatic brain injury, encephalitis, frontotemporal dementia, Alzheimer disease,

Alien Limb Syndrome

Synonyms: a.k.a. alien hand syndrome Diagnosis: This is a clinical diagnosis Clinical features: Inability to recognise ones limb once visual cues are removed or autonomous movements that are involuntary Also may have; apraxia, bimanual coordination difficulty, lack of goal directed activities Localisation: anterior corpus callosum, frontal lobe Investigations to consider: MRI: corpus callosum lesions e.g. … Continue reading Alien Limb Syndrome

Balint’s Syndrome

Diagnosis: This is a clinical diagnosis Clinical features: Ocular apraxia/ sticky fixation: the inability to move the eyes volitionally Optic ataxia: inability to reach for a target under visual guidance in the absence of primary visual deficits, patients are able to reach under auditory guidance. Simultinagnosia Investigations to consider: MRI: bilateral parietooccipital lesions Consider testing … Continue reading Balint’s Syndrome

Mild Cognitive Impairment (MCI)

Synonyms: a.k.a. Cognitive impairment no dementia CIND: Diagnosis: Clinical examination: Impairment of memory without impairment of functions in activities of daily living ADLs May be amnestic type (amnestic MCI) or non-amnestic Related articles: Approach to cognitive impairment, approach to acute confusion, dementia, Alzheimer’s disease AD, vascular dementia, Frontotemporal dementia FTD,corticobasal degeneration CBD, Progressive supranuclear palsy … Continue reading Mild Cognitive Impairment (MCI)


Diagnosis: Neuropsychological/Psychometric testing Or Clinical features The underlying etiology is determined by a combination of clinical features, neuropsychological testing, imaging and laboratory testing   Clinical features: This is an acquired persistent disorder where there is an impairment of the content of consciousness (intellectual function) with compromise in at least 2, e.g.: Memory Language i.e. aphasia … Continue reading Dementia


Diagnosis: Based on clinical features Clinical features: Retarded-stuporous form or an excited-delirious form Catalepsy, waxy flexibility, echophenomena, and negativism including mutism may occur Treatment: Benzodiazepines Electroconvulsive therapy (ECT)

Raised Intracranial Pressure, raised ICP

This is an abnormality that can occur due to multiple potential causes. It is treated based on the underlying cause and severity. Diagnosis: Intracranial pressure monitoring: Ventriculostomy (external ventricular drain EVD) Implantable ICP monitor Lumbar drain Raised opening pressure on Lumbar puncture (e.g. in cases of pseudotumor cerebri or meningitis). This should not be performed … Continue reading Raised Intracranial Pressure, raised ICP

Cerebral Edema

This is an abnormality that can occur due to multiple potential causes. It is treated based on the underlying cause and severity. Diagnosis: CT: Hypodensity Local effacement of sulci and ventricles and cisterns Blurring of the grey-white interface MRI: DWI: Allows differentiation between vasogenic (no abnormal diffusion restriction) vs. cytotoxic (abnormal diffusion restriction) types of … Continue reading Cerebral Edema

Chiari Malformation

Synonyms: Arnold Chiari malformation Chiari I malforamation: Diagnosis: MRI Clinical features: May be asymptomatic (usually this is the case) In some cases can be associated with headaches and transient brainstem dysfunction Findings on Investigations: MRI: Low lying cerebellar tonsils extending below the foramen magnum Treatment: Usually no treatment Medications for headache (but avoid overuse) In … Continue reading Chiari Malformation

JC virus Granule Cell Neuronopathy (JCV GCN)

Diagnosis: Clinical features plus MRI and evidence of JC virus infection Clinical features: ataxia Findings on Investigations: MRI: Cerebellar atrophy with or without features of PML CSF: JC virus positive Pathology, biopsy: Cerebellum: focal Internal granule cell layer loss, some enlarged granule cell neurons Special studies: Immunohistochemistry for polyomavirus: positive In situ hybridization ISH for … Continue reading JC virus Granule Cell Neuronopathy (JCV GCN)

Bickerstaff Brainstem Encephalitis (BBE)

Diagnosis: Clinical features plus antibody tests Clinical features: Decreased level of consciousness, areflexia Findings on Investigations: Anti-GQ1b IgG antibody: positive Treatment: Intravenous Immunoglobulin IVIG  

Osmotic Demyelination Syndrome

Synonyms: central pontine myelinolysis, and extrapontine myelinolysis Diagnosis: Clinical features plus MRI plus history of rapid change (increase or decrease) in sodium levels Clinical features: Encephalopathy, coma, quadriparesis, upper motor neuron signs, dysphagia Findings on Investigations: MRI : T2 : high signal in pons, basal ganglia, thalami FLAIR: high signal in pons, basal ganglia, thalami Treatment: Supportive … Continue reading Osmotic Demyelination Syndrome

Organic-Solvent Related Acute Leukoencephalopathy

Diagnosis: Clincial features, exposure to solvent and MRI Clinical features: Solvent exposure Rapidly progressive dementia, akinetic mute, other features Findings on Investigations: MRI: Diffuse symmetric involvement of white matter Pathology: PAS-positive macrophages Electron microscopy EM: membrane-bound lamellar material within macrophage Treatment: Supportive care Related articles: Approach to cognitive impairment, approach to acute confusion, Leukoencephalopathy, Acute … Continue reading Organic-Solvent Related Acute Leukoencephalopathy

Heroin related Acute leukoencephalopathy “chasing the dragon"

Diagnosis: Clinical features plus MRI Clinical features: Initially: Ataxia, dysmetria, and dysarthria, gait abnormalities Later on: akinetic mute, spastic quadraparesis, After recover: tremor Inhalation of vaporised heroin (heroin pyrolysate) “chasing the dragon” Findings on Investigations: MRI: Involvement of white matter (cerebellum, posterior cerebrum, posterior limbs of the internal capsule, splenium of the corpus callosum, medial … Continue reading Heroin related Acute leukoencephalopathy “chasing the dragon"

Hashimoto Encephalopathy

Synonyms: Steroid Responsive Encephalopathy Associated With Autoimmune Thyroiditis SREAT a.k.a. Hashimoto’s encephalopathy Diagnosis: A diagnosis by exclusion with the following: Encephalopathy characterised by: Tremor, transient aphasia, myoclonus, gait ataxia, seizures, and sleep abnormalities +no other identifiable cause +Positive antithyroid antibodies: anti-thyroglobulin or anti-thyroperoxidase antibodies +/-abnormal TFTs: usually hypothyroidism, but may be euthyroid to hyperthyroid +response … Continue reading Hashimoto Encephalopathy

Progressive Multifocal Leukoencephalopathy (PML)

Diagnosis: Clinical and imaging features plus laboratory findings Clinical features: Gradual onset & progressive. Seizures & aphasia may occur Occurs in the setting of immunosupression: e.g. HIV infection/AIDS, immunosupressant medications, Findings on Investigations: JC virus in CSF: by PCR MRI: White matter lesions, usually asymmetric but bilateral, periventricular and subcortical involvement of U fibres, spares … Continue reading Progressive Multifocal Leukoencephalopathy (PML)

Disseminated Necrotizing Leukoencephalopathy (DNL)

Synonyms: a.k.a. Multifocal necrotizing leukoencephalopathy Diagnosis: Clinical +MRI +/-biopsy Occurs after Radiation therapy and/or chemotherapy Clinical features: Encephalopathy Occurs after Radiation therapy and/or chemotherapy Findings on Investigations: CT: White matter, Periventricular, centrum semiovale. Spares the U fibres Hypodensity in white matter. Enhancement can occur. MRI: White matter, Periventricular, centrum semiovale. Spares the U fibres T2 … Continue reading Disseminated Necrotizing Leukoencephalopathy (DNL)

Acute Disseminated Encephalomyelitis (ADEM)

Synonyms: a.k.a. Acute dissemniated leukoencephalitis a.k.a. Acute postinfectious/post-vaccinial perivenous encephalitis, a.k.a. acute demyelinating encephalomyelitis, Diagnosis: Clinical  features plus MRI and supportive tests Clinical features: Encephalopathy, focal findings may occur. Often follows an infectious illness or exposure to new antigen to medication Findings on Investigations: MRI T2: preferred. High signal intensities (large patchy) in white matter … Continue reading Acute Disseminated Encephalomyelitis (ADEM)

Empty Sella Syndrome

Diagnosis: An imaging finding that may or may not be associated with clinical features Clinical features: Mild headache, CSF rhinorrhea, hypertension, obesity Findings on Investigations: CT: empty sella i.e. sella turcica that is completely or partially filled with CSF, MRI: empty sella i.e. sella turcica that is completely or partially filled with CSF, TSH, gonadotrophin: … Continue reading Empty Sella Syndrome

Biotin-Responsive Encephalopathy

Diagnosis: Clinical features, laboratory testing and MRI Clinical features: Ophthalmoplegia, nystagmus, ataxia, diplopia and ptosis Complex partial seizures with status epilepticus. Thiamine-responsive Genetics: Thiamine-Transporter Gene Findings on Investigations: MRI: High-intensity signals in the bilateral medial thalamus Laboratory: Thiamine levels: normal Treatment: Thiamine Related articles: Approach to cognitive impairment, approach to acute confusion, approach to diplopia, … Continue reading Biotin-Responsive Encephalopathy

Wernicke Encephalopathy

Diagnosis: Clinical features lone or with MRI findings or low B1 levels +/-Response to thiamine treatment +/-B1 Thiamine: by functional transketolase assay, thiamine chromatography or urinary thiamine Clinical features: Triad: Confusion, ataxia, ophthalmoplegia Not all features are necessary. Occasionally hypothermia occurs. Findings on Investigations: MRI features: Hyperintense signals in the periaqueductal gray area, dorsal medial … Continue reading Wernicke Encephalopathy

Normal Pressure Hydrocephalus

Diagnosis: A combination of clinical features, response to high volume lumbar puncture spinal tap plus imaging Clinical features: Gait disorder, the first symptom: Marche a petis pas: wide-based slow shuffling gait Ignition failure: hesitation on starting to walk Magnetic foot: difficulty lifting foot of the ground Poor postural control Cognitive impairment: Apathy, memory impairment Urinary … Continue reading Normal Pressure Hydrocephalus

Frontotemporal Dementia (FTD)

Synonyms: a.k.a. Frontotemporal lobar dementia FTLD Diagnosis: Clinical features, plus supportive imaging Clinical features: Behavioural symptoms: Progressive change in personality Decline of reasoning Social inappropriateness Primary progressive aphasia: Anomia (inability to retrieve nouns upon demand), Agrammatism (inappropriate word order or use of prepositions), Loss of semantic knowledge about words and objects Clinical variants: progressive nonfluent … Continue reading Frontotemporal Dementia (FTD)

Vascular Parkinsonism

Diagnosis: Clinical features plus supportive MRI and poor response to dopamine agonists Clinical features: Lower body Parkinsonism. Variable cognitive & behavioural deficits. May accompany vascular dementia Findings on Imaging: MRI: multiple subcortical infarcts +/-subcortical leukoaraiosis Treatment: Supportive care Address vascular risk factors Related articles: Approach to movement disorders, Idiopathic Parkinson disease, vascular dementia, ischemic stroke,

Vascular Dementia

Diagnosis: Vascular dementia VaD, NINDS AIREN criteria for probable disease: Dementia +evidence of cerebrovascular disease +a relationship between them Evidence of cerebrovascular disease: Clinical features: Exam showing evidence of previous Also, a triad of: short shuffling gait “marche au petit pas”, pseudobulbar palsy, pseudobulbar affect can occur. MRI (1st choice) or CT: Large vessel disease: Bilateral … Continue reading Vascular Dementia

Transient Global Amnesia

Diagnosis: Clinical features plus supported investigations Clinical features: Acute onset. Lasts 1-24 hours. Complete antrograde amnesia & limited retrograde amnesia (weeks or months). May be disoriented to time, place but not to self. Preserved cognitive functions apart from memory & disorientation No decrease in level of consciousness. Able to interact appropriately during the episode No … Continue reading Transient Global Amnesia


Diagnosis: Clinical features: ataxia, loss of facial motor control, dementia, leg pain Pathology: PRNP gene chr. 20p codon 129 status: MM is a risk factor, Related articles: Approach to cognitive impairment, approach to movement disorders, Sporadic CJD,

Gerstmann–Sträussler–Scheinker Syndrome:

Diagnosis: Clinical features plus imaging Clinical features: 2-10 years, Progressive ataxia & dementia Truncal ataxia, dysesthesia and hyporeflexia of the lower legs, and mild dysarthria Supranuclear gaze palsy Pyramidal signs Pathology: Amyloid plaques: PrP positive Minimal spongiform (vacuolar) change PRNP gene (GSS102) chr. 20p mutation usually Pro102Leu, octapeptide repeats also occur. Findings on Investigations: EEG: … Continue reading Gerstmann–Sträussler–Scheinker Syndrome:

Fatal Familial Insomia

Diagnosis: Combination of clinical features and imaging Genetics: Autosomal dominant Clinical features: Insomnia, sympathetic over activity, impaired attention Ataxia, dysarthria, Memory loss Hormone abnormalities: increased cortisol, Polysomnography: reduced total sleep time, absent REM sleep, absent deep nonREM sleep, Findings on Investigations: MRI: Normal or cerebral or cerebellar atrophy PET: Decreased metabolism in the thalami CSF: … Continue reading Fatal Familial Insomia

Variant Creudtzfedt-Jakob Disease (vCJD)

Synonyms: New variant CJD, Diagnosis: Clinical +/-EEG +/-MRI +/-CSF findings +/-brain biopsy Clinical features: Abnormal movements (myoclonus, dystonia, chorea), ataxia, slurred speech, tremor, dementia, akinetic mutism Non-specific sensory symptoms Psychiatric symptoms: withdrawal, delusions, depression Findings on Investigations: MRI: Thalamic hyperintensities: bilateral pulvinar (posterior thalamus) a.k.a. ‘Pulvinar sign’. In some there is also bilateral dorsomedial nucleus … Continue reading Variant Creudtzfedt-Jakob Disease (vCJD)

Sporadic Creutzfeldt-Jakob Disease (sCJD)

Diagnosis: A type of transmissible spongiform encephalopathy TSE Clinical +/-EEG +/-MRI +/-CSF findings +/-brain biopsy Clinical features: Rapidly progressive, death usually <1 year Dementia (rapidly progressive), ataxia, myoclonus, rigidity, visual disturbances Focal cortical symptoms (aphasia, neglect, apraxia, acalculia) Akinetic mutism (late feature) Heidenhain variant: Visual symptoms: perception difficulties (colours & structures e.g. metamorphopsia/dysmorphopsia), optical hallucinations, … Continue reading Sporadic Creutzfeldt-Jakob Disease (sCJD)

Fungal Intracranial Abscess

Candida abscess: Diagnosis: Biopsy or blood culture isolation of organisms Treatment: Fluconazole, amphotericin B   Cryptococcosis (Cryptococcus neoformans): See under Cryptococcosis (Cryptococcus neoformans), Cryptococcal meningitis & related   Aspergillosis a.k.a. Aspergillus fumigatus or flavus: Diagnosis: Suggested by MRI, but confirmed by biopsy Pathology: Biopsy: Within distribution of anterior or middle cerebral artery. Multiple. Necrosis, hemorrhage. … Continue reading Fungal Intracranial Abscess

Spinal Cord Abscess

Diagnosis: A combination of clinical features, MRI, and biopsy Clinical features: Features of myelopathy Findings on investigations: MRI: intramedullary ring enhancing lesion, Spinal cord biopsy & culture: confirmatory of organisms Treatment: Antibiotics Consider surgical drainage Related articles: Approach to weakness, Bacterial Meningitis, intracranial empyema, brain abscess, epidural abscess (brain or spinal),

Epidural Abscess (intracranial or spinal)

Diagnosis: Imaging (MRI with and without contrast) plus biopsy for confirmation Pathology: Biopsy: Necrosis with inflammation (neutrophils & later macrophages & lymphocytes), rim of fibrosis (if absent this is cerebritis) Surrounding gliosis Clinical features: Intracranial: focal neurological deficit Spinal: transverse myelopathy and a flexed posture resisting extension, back pain with fever. Investigations to consider: FBC, … Continue reading Epidural Abscess (intracranial or spinal)

Brain Abscess

Synonyms: Intracranial abscess a.k.a. intracerebral abscess: Diagnosis: Suggested by imaigng. Confirmed by biopsy and culture Clinical features: Presents with focal neurological deficits: weakness, aphasia, neglect May present with headache or seizure Meningismus in <30% Pathology: Biopsy: Necrosis with inflammation (neutrophils & later macrophages & lymphocytes), rim of fibrosis (if absent this is cerebritis) Surrounding gliosis … Continue reading Brain Abscess

Intracranial Empyema

Diagnosis: A combination of clinical features, imaging and Growth on cultures from the collection Clinical features: seizures, cognitive dysfunction, hemispheric symptoms (aphasia, apraxia, hemiparesis) Findings on Investigations: CT: cavity +low density +gas MRI: resectricted diffusion in an axtra-axial collection Growth on cultures from the collection Related articles: Approach to cognitive dysfunction, Approach to weakness, Epilepsy,

Subacute Sclerosing Panencephalitis (SSPE)

Diagnosis: Clinical features, plus EEG Clinical features: Previous measles infection. Children or young adults. Subacute onset of progressive cognitive deficits, behavioural problems, spasticity, rigidity, Myoclonus, generalised seizures Findings on Investigations: EEG: flat with episodic bursts Anti-measles antibodies CSF: raised IgG index Pathology: Gross: hard brain (gliosis), Microscopic: intracellular (type A) and intracytoplasmic neuronal and glial … Continue reading Subacute Sclerosing Panencephalitis (SSPE)

HIV Associated Neurocognitive Disorders (HAND)

Synonyms: HIV associated dementia HAD, formerly Subacute or Chronic HIV encephalitis a.k.a. AIDS dementia complex formerly AIDS encephalopathy/AIDS encephalitis Diagnosis: Acquired impairment in at least 2 cognitive domains: Learning, information processing speed, attention/concentration +Marked impairment of ADLS +No delirium +No other cause for dementia Other features & tests: Limb incoordination, gait ataxia, abnormal smooth pursuit … Continue reading HIV Associated Neurocognitive Disorders (HAND)

Nonparaneoplastic Autoimmune Limibic Encephalitis

Diagnosis: Clinical features plus antibodies and negative investigations for neoplastic disease Clinical features: Subacute impairment, seizures, temporal lobe seizures & hallucinations, Findings on Investigations: Associated antibodies: VGKC, voltage-gated potassium channels (Kv1) antibodies: These are positive in patients with limbic encephalitis, Morovan’s syndrome. These have differnet targets. Lgi1: leucine-rich, glioma inactivated 1 protein, a subtype of … Continue reading Nonparaneoplastic Autoimmune Limibic Encephalitis

Paraneoplastic Encephalomyelitis, Paraneoplastic Encephalitis

Synonyms: a.k.a. paraneoplastic encephalitis, a.k.a. paraneoplastic limbic encephalits Diagnosis: A combination of serology,  clinical features and identification of underlying tumor Clinical features: Subacute impairment, seizures, temporal lobe seizures & hallucinations, Other features may occur:, Pathology: Limbic encephalitis (medial temporal lobe, hippocampus, amygdala, cingulate gyrus, inula), thalamus, brainstem encephalitis, cerebellum, spinal cord grey matter, dorsal root … Continue reading Paraneoplastic Encephalomyelitis, Paraneoplastic Encephalitis

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS)

Diagnosis: Clinical features, MRI and occasionally biopsy Clinical features: Episodic diplopia or facial paresthesias with subsequent brainstem and occasionally myelopathic symptoms and had a favourable initial response to high dose glucocorticosteroids Findings on Investigations: +MRI: Symmetric curvilinear gadolinium enhancement peppering the pons and extending variably into the medulla, brachium pontis, cerebellum, midbrain and occasionally spinal … Continue reading Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS)

Optic Neuritis

Diagnosis: Clinical features with or without imaging or physiological tests Clinical features: Painful, loss of vision, & loss of accurate colour vision (dyschromatopsia) Fundoscopy: swollen optic disc (optic disc edema, this is not papilledema because pressure is normal), Relative afferent papillary defect Findings on Investigations: MRI: T2 fat suppressed, high signal foci in the optic … Continue reading Optic Neuritis

Neuromyelitis Optica

Synonyms: a.k.a. Devic’s disease Diagnosis: A combination of clinical features, NMO-IgG antibodies and imaging Clinical features: simultaneous or sequential occurrence of optic neuritis and myelitis (usually acute complete transverse myelitis). Findings on Investigations: MRI: Spinal cord lesion =or> 3 segments long Non-diagnostic for Multiple sclerosis White matter lesions that are long & extend from the … Continue reading Neuromyelitis Optica

Lumbar spinal stenosis

Synonyms: formerly ‘pseudoclaudication’ Diagnosis: Any developmental or acquired narrowing of the spinal canal (spinal canal stenosis), nerve root canal, or intervertebral foramina a.k.a. neural foramina, that results in compression of neural elements Clinical features: (must be present) Pain & numbness in lower back, buttocks & legs on walking or lumbar extension History: Painful gait, Absence … Continue reading Lumbar spinal stenosis

Spondylolisthesis and Spondylolysis

Diagnosis: These are imaging findings. Whether they are the cause of deficits requires clinical correlation plus electrophysiology as necessary Spondylolisthesis: Slipping of one vertebra upon another Spondylolysis: a bony defect (fracture) in the pars interarticularis (connects the pedicle and lamina on axial plane, connects superior and inferior articular processes of the facet joints on sagittal … Continue reading Spondylolisthesis and Spondylolysis

Cervical Spondylosis

Note this can cause myelopathy and radiculopathy Synonyms: a.k.a. osteoarthropathy of the cervical spine Diagnosis: Imaging confirms the presence of degenerative changes but doesn’t confirm that it is the cause of radiculopathy or myelopathy X-ray spine: Osteophytes, narrowed disk spaces, narrowed framina This confirms the presence of degenerative changes but doesn’t confirm that it is … Continue reading Cervical Spondylosis

Subacute Combined Degeneration of the Spinal Cord

Diagnosis: Low B12 level or normal lower limit B12 with high methylmalonic acid MRI T2: expanded spinal cord, high signal in posterior columns Pathology: Shrunken thoracic cord, discoloured posterior & lateral columns Microscopically: Thoracic cord, bilateral symmetrical white matter vacuolar degeneration “spongy appearance” affecting the long tracts, lipid-laden macrophages, Wallarian degeneration of some axons. Gliosis … Continue reading Subacute Combined Degeneration of the Spinal Cord


Diagnosis: Clinical features plus MRI Clinical features: Suspended sensory level (loss of pain & temperature at a level on both sides), Later on absent reflexes & weakness Scoliosis, foot deformity (pes cavus, equinovarus), Charcot joint at the shoulder may occur Findings on Investigations: MRI: Cavity within the spinal cord, same signal characteristics as CSF Associated … Continue reading Syringomyelia

Radiation Induced Spinal Cord Hemorrhage

Diagnosis: Clinical features plus MRI Clinical features: Sudden onset of weakness & sensory symptoms Many years after radiation exposure MRI: Spinal cord hemorrhage Related articles: Approach to weakness, Radiation myelopathy,

Radiation Myelopathy

Diagnosis: Clinical features, plus exclusion of other causes Clinical features: Recent or distant exposure to radiation +signs of myelopathy: Lhermitte’s sign, Brown-Sequard lesion is classic Acute or insidious onset. Transient & progressive forms Findings on Investigations: MRI: Radiation change in the vertebra; increased signal Normal initially Later: T1 hypointese, T2/FLAIR hyperintense, enhances, CSF: raised protein … Continue reading Radiation Myelopathy

Schistosomal Myeloradiculopathy

Schistosomal myelopathy and radiculopathy Diagnosis: A combination of Schistosoma tests plus MRI and clinical features Clinical features: Features of myelopathy & radiculopathy & current or past Schistosomal infection Findings on Investigations: MRI: lower thoracic & cona medularis or cauda equina, enlargement, T2 hyperintensity, T1 gadolinium enhancement (linear or micronodular) Tests for: S. mansoni or S. … Continue reading Schistosomal Myeloradiculopathy

HTLV-1 Myelitis

Synonyms: a.k.a. tropical spastic paraparesis Diagnosis: Clinical features: features of myelopathy MRI: may show T2 hyperintense lesions Viral studies: HTLV-1 viral load= mean of 83 copies/100 cells in TSP vs. a mean of 1.9 copies/100 cells in HTLV-1 infected, nonTSP patients. Related articles: Approach to weakness,

Viral Myelitis

Diagnosis: Clinical +MRI +laboratory studies +evidence of viral infection Types: Herpes viruses: CMV myelitis HSV myelitis VZV myelitis: VZV PCR or antibodies against VZV EBV myelitis HHV6 HIV myelitis HTLV-1 myelitis: serology Enteroviruses, Echovirus, coxsackie virus, hepatitis A, hepatitis B, rubella, measles, mumps, lymphocytic choriomeningitis LCM Poliomyelitis, West nile virus: +/- LMN signs Treatment: Treat … Continue reading Viral Myelitis

Idiopathic Acute Transverse Myelitis

Synonyms: a.k.a. Primary transverse myelitis Diagnosis: Clinical +MRI +laboratory studies +evidence of inflammation by CSF: pleocytosis or raised IgG index, or by MRI enchancement +exclude secondary disease: including vascular myelopathy Clinical features: Acute or subacute onset Bilateral symptoms and/or signs, usually symmetric i.e. acute complete transverse myelitis ACTM. [142] Acute partial transverse myelitis APTM may … Continue reading Idiopathic Acute Transverse Myelitis

Spinal Cord Infarction

Synonyms: a.k.a. anterior spinal artery syndrome: Clinical features: Back pain +sudden paraplegia with areflexia & urinary retention, loss of touch, temperature, Usually spares proprioception & vibration Findings in Investigations: +MRI: may be negative initially Hyperintensity in the spinal cord, slightly expanded spinal cord later on Note: T1-T4 & T5-T7 are the vascular boundary zones Investigations … Continue reading Spinal Cord Infarction

Spinal Cord compression (compression myelopathy)

Clinical features: Weakness (quadraparisis or paraparesis), sensory level, bowel and bladder dysfunction Findings on Investigations: MRI: Compression of the spinal cord T2/STIR: hyperintensity in the spinal cord Treatment: Treat the underlying condition Consider early surgical decompression If metastatic: Dexamethasone: dose is debatable; initial trials used 100 mg I.V. over 0.5-1 hour, then 4 mg q6 … Continue reading Spinal Cord compression (compression myelopathy)

Simple Faints

Synonyms: a.k.a. neurally mediated syncope a.k.a. Vasovagal syncope a.k.a. neurocardiogenic syncope a.k.a. vasodepressor syncope: Clinical features: Syncope after emotional stimulus Syncope after Valsalva & Valsalva like: Cough, defaecation, Micturation, Deglutition, Hyperventilation Syncope after hemodynamic/orthostatic stress e.g. prolonged standing Preceded by autonomic activation: Cold sweat: piloerection, sweating & pallor (vasoconstriction) Nausea & epigastric discomfort (vagal activation) … Continue reading Simple Faints

Subclavian Steal Syndrome

Diagnosis: Clinical features plus imaging Clinical features: Difference in BP between arms Findings on Investigations: Vertebral ultrasound: Reversal of flow in vertebral artery Catheter angiography: Subclavian stenosis or occlusion With reversal of flow in vertebral artery Treatment: Treat only if symptomatic Angioplasty or stenting of subclavian artery Occlusion of vertebral artery Carotid subclavian bypass Related … Continue reading Subclavian Steal Syndrome

Chilhood Epilepsy Syndromes

For each syndrome seizure disorder a combination of history, physical examination & EEG are used Childhood absence epilepsy CAE Juvenile absence epilepsy JAE West syndrome a.k.a. Infantile spasms Aicardi syndrome a.k.a. Aicardi-Goutieres syndrome Jeavons Syndrome (Eyelid myoclonia with or without absences) Lennox-Gestuat syndrome Benign epilepsy with centrotemporal spikes BECTS a.k.a. benign rolandic epilepsy Juvenile myoclonic … Continue reading Chilhood Epilepsy Syndromes

Autosomal dominant partial epilepsy with auditory features (ADTLE)

Synonyms: a.k.a. Autosomal dominant lateral temporal epilepsy Genetics: Autosomal dominant LGI1 gene (leucine-rich glioma inactiated) chr. 10q Clinical features: Auditory symptoms (buzzing, ringing, volume changes, songs, voices),receptive aphasia as ictal manifestations, seizures precipitated by sounds Related articles: Epilepsy,

Generalised epilepsy with febrile seizures plus (GEFS+)

Genetics: Autosomal dominant, familial Na+: SCN1A chr. 2q24. Alpha 1 subunit SCN1B chr. 19q13.1, Beta 1 subunit (incomplete penetrance) GABA: GABRG2 chr. 5q31, Gamma2 subunit (incomplete penetrance) Clinical features: Febrile seizures >6 y.o. or Generalised seizures without fever: GTCS, myoclonic, absence & atonic seizures Related articles: Epilepsy,

Autosomal Dominant Nocturnal Frontal Lobe Epilepsy (ADNFLE)

Diagnosis: A type of channelopathy Diagnosed by clinical features, plus EEG Genetics: Autosomal dominant CHRNA4 chr. 20q13.2, ENFL2 chr. 15q24 Clinical features: 1st & 2nd decades, persist. Seizures occurring exclusively in drowsiness or sleep. EEG: frontal origin, clusters. Interictally: normal Related articles: Epilepsy,

Benign Familial Neonatal Seizures

Synonyms: a.k.a. Benign Familial neonatal convulsions (benign infantile epilepsy) Diagnosis: A type of channelopathy Diagnosed clinically Genetics: Autosomal dominant. K+ KCNQ2 or KCNQ3 Clinical features: Neonatal seizure clearing spontaneously after a few weeks. Onset on Day 3 remission by week 6 Normal development afterwards A minority have epilepsy Related articles: Epilepsy,

Myoclonic Astatic Epilepsy of Childhood

Diagnosis: Clinical plus EEG Clinical features: 2-5 years old. Initially GTCS occur, then myoclonic seizures & drop attacks develop. Usual attacks have myoclonic jerks followed by drop attacks. Status epilepticus occurs. Findings on Investigations: EEG: Background of 4- to 7-Hz rhythm. Regular or irregular bilaterally synchronous 2- to 3-Hz spike-waves and/or polyspike-waves. Sleep increases he … Continue reading Myoclonic Astatic Epilepsy of Childhood

Severe Myoclonic Epilepsy of Infancy

Synonyms: a.k.a. Dravet’s syndrome Genetics: Na+ SCN1A 2q24 de novo mutations Clinical features: Onset <1y.o., tonic-clonic seizures Later; myclonic, absense & partial seizures +speech & motor arrest & reduced life expectancy Treatment: Valproate VPA Topiramate TPM, clonazepam, clobazam Related articles: Epilepsy.

Focal epilepsy (cryptogenic, symptomatic)

Diagnosis: Clinical features, EEG with negative tests for secondary causes Clinical features: partial epilepsy Findings on Investigations: EEG: partial seizures MRI: no lesions Treatment: Valproate VPA, Carbamazepine CBZ Lamotrigrine, Topiramate TPM, oxacarbazepine Related articles: Epilepsy,

Idiopathic generalized epilepsy with Generalized tonic-clonic seizures only

Diagnosis: Clinical plus EEG Clinical features: generalised tonic-clonic seizures Findings on Investigations: EEG: generalised spike & wave Treatment: Carbamazepine CBZ, Valproate VPA Lamotrigrine, Topiramate TPM Related articles: Epilepsy,

Juvenile Myoclonic Epilepsy (JME)

Synonyms: a.k.a. Janz syndrome Diagnosis: Clinical features plus EEG Clinical features: myoclonic jerks, shortly after waking. Generalized tonic clonic seizures triggered by sleep deprivation Findings on Investigations: EEG: 4-6 Hz generalized spike wave. Treatment: Life long Valproate VPA orally (except in women of childbearing age) Lamotrigrine, Levetiracetam LEV, Topiramate TPM, primidone Related articles: Epilepsy,

Benign epilepsy with centrotemporal spikes (BECTS)

Synonyms: a.k.a. benign rolandic epilepsy Diagnosis: Clinical features pluse EEG Clinical features: Onset 5-10 years old., < 15 years old Resolves by age 16 years old Nocturnal seizures with mouth movement & gurgling, may generalise Findings on Investigations: EEG: centro-temporal ‘rolandic’ sharp wave activity on normal background, increases during sleep. Has characteristic dipole Treatment: Carbamazepine … Continue reading Benign epilepsy with centrotemporal spikes (BECTS)

Lennox-Gestuat Syndrome

Diagnosis: Clinical features and EEG Clinical features: Onset 1-10 years old Multiple seizure types Mental retardation Findings on Investigations: EEG: Frontocentral slow spike-and-wave discharges <3 Hz & other abnormalities Generalized paroxysmal fast activity Treatment: Valproate VPA Lamotrigrine, Topiramate TPM, felbamate Related articles: Epilepsy,

Aicardi Syndrome

Synonyms: a.k.a. Aicardi-Goutieres syndrome, Diagnosis: Triad: Infantile spasms in flexion agenesis of corpus callosum ocular abnormalities Clinical features: Birth to childhood, progressive encephalopathy Seizures: infantile spasms, alternanting hemiconvulsions Microcephaly, spasticity, dystonia, Ocular: Visual inattention and abnormal eye movement Coloboma, lacunes in the retina, Fatal or persistent vegetative state Genetics: X-linked dominant Heterogenous Findings on Investigations: … Continue reading Aicardi Syndrome

West Syndrome

Synonyms: a.k.a. Infantile spasms Diagnosis: Clinical features plus EEG Clinical features: Onset 3 months – 3 years, Jack-knifing, myoclonus +/-mental retardation Findings on Investigations: EEG: hypsarrhythmia i.e. chaotic slow-wave high voltage background activity & sharp components High amplitude (voltage >200 microV) Slow waves, Sharps waves & spikes in all areas Sharps & spikes appear randomly … Continue reading West Syndrome

Juvenile Absence Epilepsy

Diagnosis: EEG: bilaterally synchronus 3 per second spike-and-wave Treatment: Valproate VPA Lamotrigrine Related articles: Epilepsy,

Progressive Myoclonic Epilepsy (PME)

Unverricht-Lundborg a.k.a. Baltic myoclonus Myoclonic epilepsy and ragged red fibres Lafora disease Neuronal ceroid lipofuscinosis Gaucher disease GM2 Gangliosidosis, hexosaminidase deficiency Sialidosis Juvenile neuroaxonal atrophy Dentatorubral-Pallidoluysian atrophy Related articles: Approach to cognitive impairment, Epilepsy,  

Neuronal Ceroid Lipofuscinosis

Synonyms: Jansky-Bielschowsky, (Spielmeyer-Vogt-Sjogren) Batten, (Parry) Kuf, Santavori Diagnosis: A group of lysosomal storage disorders Types: Infantile INCL Type 2: Late infantile LINCL a.k.a. Classic a.k.a. Jansky-Bielschowsky disease Type 3: Juvenile JNCL a.k.a. Spielmeyer-Vogt-Sjogren disease, or Batten disease Type 4: Adult ANCL a.k.a. Kuf’s disease, or Parry disease. No visual failure Type 5: Finish variant Genetics: … Continue reading Neuronal Ceroid Lipofuscinosis

GM2 Gangliosidosis, Hexosaminidase Deficiency

Diagnosis: A type of lysosomal storage disease. Also a sphingolipidosis. Subtypes: Tay-Sachs disease: hexosaminidase A gene mutation, HEXA gene chr. 15q, encodes the alpha subunit Sandhoff disease: hexosaminidase B gene mutation, HEXB gene chr. 5q, encodes the beta subunit AB variant a.k.a. GM2 activator deficiency: GM2A gene chr. 5q, encodes activator protein Related articles: Epilepsy,

Gaucher Disease

Synonyms: a.k.a. Glucosylcerebrosidase deficiency Diagnosis: A type of lysosomal storage disease. A type of sphingolipidosis. Also a type of Progressive myoclonic epilepsy Genetics: Autosomal recessive Subtypes: Type 1 Type 2, absent enzyme activity Type 3, “neurological”: Supranuclera gaze palsy, myoclonus, no dementia Splenomegaly, pancytopenia Pathology: Ectopic dendritogenesis, meganeurites Treatment: Options as below Enzyme replacement therapy: … Continue reading Gaucher Disease

Myoclonic Epilepsy and Ragged Red Fibres (MERRF)

Genetics: mitochondrial DNA mutation Diagnosis: A form of progressive myoclonic epilepsy Clinical features: Myopathy, neuropathy Deafness Lipomas Optic atrophy Myoclonus Genetics: Familial, sporadic, maternal Mitochondrial DNA mutation Pathology: Ragged red fibres in muscle. Changes in Dentate nucleus & inferior olive Related articles: Epilepsy, mitochondrial disorders,

Juvenile Neuroaxonal Atrophy

A form of progressive myoclonic epilepsy Clinical features: Myoclonus, dementia, ataxia Neuropathy, choreoathetosis Choreoathetosis appears when myoclonus is suppressed & vice versa Pathology: Autonomic terminals: Axonal spheroids Related articles: Epilepsy, Approach to cognitive impairment,


A form of progressive myoclonic epilepsy Type 1: Clinical features: Adolescence, severe myoclonus, gradual visual loss, ataxia Cherry-red spot No dementia Genetics: Autosomal recessive Chr. 20 Pathology: Decreased neuraminidase   Type 2: Clinical features: adolescence, severe myoclonus, gradual visual loss, ataxia Cherry-red spot No dementia Coarse facies, corneal clouding Genetics: Autosomal recessive, Chr. 10 Pathology: … Continue reading Sialidosis

Lafora Disease

A form of progressive myoclonic epilepsy Diagnosis: Clinical features plus EEG and pathology Genetics: EPM2A gene chr. 6q24, protein= laforin (a dual phosphatase), EPM2B gene chr. 6q22.3 a.k.a. NHLRC1 gene, protein = malin (a E3 ubiquitin ligase) Clinical features: Age 10-18 y.o. epilepsy, segmental massive myoclonus, rapidly progressive mental deterioration (dementia), ataxia. Findings on Investigations: … Continue reading Lafora Disease

Unverricht-Lundborg Disease

Synonyms: a.k.a. Baltic myoclonus A form of progressive myoclonic epilepsy Diagnosis: Clinical features plus genetics Clinical features: Age 6-16, myoclonus, ataxia, dementia Absence, atonic seizures may occur Genetics: Autosomal recessive Chr. 21q Pathology: Affects cerebellum, thalamus, spinal cord Neuronal loss, gliosis Related articles: Epilepsy,

Nitromethane Encephalopathy

Diagnosis: Clinical plus imaging Clinical features: Seizures (generalised or partial), dysmetria, intension tremor, ataxia Findings on Investigations: MRI: T2 high intensity in cerebellar white matter, tonsils, uvula, and colliculi. Features may resolve on follow up Related articles: Epilepsy,

Alcohol Withdrawal

Synonyms and related conditions: Alcohol withdrawal seizures & delirium tremens DT Diagnosis: This is a clinical diagnosis Clinical features Within 6-36 hours of cessation of/decrease in alcohol consumption, Autonomic symptoms: diaphoresis, tachycardia, and hypertension Neurological symptoms: tremor, anxiety, hallucinations (tactile, visual or auditory), agitation, seizures, headache, insomnia. Delirium tremens DTs: Alcohol withdrawal +disorientation, confusion, agitation … Continue reading Alcohol Withdrawal


Synonyms: Taenia solium (pork tapeworm) Diagnosis: Imaging plus clinical features Clinical features: Seizures, Meningitis may occur Findings on Investigations: MRI: T1 +contrast: multiple ring enhancing lesions with edema T1, punctuate signal void FLAIR: hyperintensity (gliosis) surrounds the lesions CT: Multiple calcified lesions +/-surrounding edema Migrating intraventricular cyst +positive serology for neurocysticercosis Treatment: Albendazole 800mg P.O. … Continue reading Neurocysticercosis

Rasmussen Encephalitis

Diagnosis: A combination of clinical, MRI and EEG findings Clinical features: Childhood onset Intractable partial seizures, worsen with time, epilepsia partialis continua, hemiplegia, aphasia Findings on Investigations: MRI: White matter hyperintensity and then atrophy EEG: Focal and multifocal epileptiform discharges and slowing Pathology: Cortical atrophy, perivascular lymphocytic infiltrates with vascular injury, astorcytic gliosis, neuronal loss … Continue reading Rasmussen Encephalitis

Transient Epileptic Amnesia

Diagnosis: Clincial features plus supporitng EEG Clinical features: Older adults Transient episode of memory loss. 30-60 minutes in duration. Recurs. +1 of the following 3: Clinical features of epilepsy such as lip-smacking or olfactory hallucinations Epileptiform abnormalities on electroencephalogram (EEG) Clear response to anticonvulsant therapy. Related articles: Epilepsy, Approach to acute confusion, Transient global amnesia,

Gastaut-Geschwind Syndrome

Diagnosis: Clinical plus EEG findings Clinical features: Hypergraphia, hyposexuality, hyperreligiosity, and interpersonal viscosity Occuring in some patients with temporal lobe epilepsy. Related articles: Epilepsy,


Diagnosis: Pathology is the gold standard, but MRI is an excellent test for diagnosis Clinical features: epilepsy Findings on Investigations: MRI: Subepindymal, subcortical or band/diffuse Subcortical band heterotopia FDG-PET: Intertictal: increase uptake in the subcortical band. EEG: interictal & ictal abnormalities Genetic forms: doublecortin (DCX) gene, X-linked. Blood testing available. MRI in affected men: lissencephaly, … Continue reading Heterotopia

Mesotemporal Sclerosis

Synonyms: a.k.a. mesial temporal sclerosis a.k.a. Amon’s horn sclerosis a.k.a. hippocampal sclerosis Diagnosis: Pathology is the gold standard, but MRI is very sensitive Pathology: Gold standard Atrophy, white discolouration of the hippocampal formation, enlarged temporal horn of the lateral ventricle. Fornix atrophy. Microscopically: loss of neurons (pyramidal & dentate layer) in CA1 (Sommer sector) & … Continue reading Mesotemporal Sclerosis

Status Epilepticus

Diagnosis: Clinical supported by EEG Clinical features: This is an emergency & should be treated as soon as recognised, before EEG or tests A seizure or multiple seizures without regaining consciousness in between lasting >10 min Findings on Investigations: EEG: there is a sequence of EEG findings. 1 discrete seizures 2 merging seizures with waxing … Continue reading Status Epilepticus


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: Eye, optic nerve, pineal gland Pathology: Grossly: White tan mass Histology: Small round blue cells, rosette (Homer-Wright around neuritic processes & Flexner-Wintersteiner around a central lumen), necrosis, frequent mitosis Immunohistochemistry: NSE, NeuN, synaptophysin Genetics: RB gene mutation 13q14, germline. Related articles: Brain … Continue reading Retinoblastoma


Synonyms and subtypes: a.k.a. carotid body tumor, glomus jugulare tumor, glomus tympanicum Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: Neck mass (carotid body tumor, glomus jugulare tumor), middle ear canal mass (glomus tympanicum) Filum terminale Enhancing lesion MRA: blood supply can be assessed. Catheter Angiogram: To assess vascular … Continue reading Paraganglioma

Neurofibromatosis (NF)

Diagnosis: Clinical features: NF 1, two or more of the following: >5 Café au lait spots Neurofibroma: 2 or more neurofibroma or 1 plexiform neurofibroma Freckles in the axilla or inguinal area a.k.a. Crowe’s sign 2 or more Lisch nodules (iris hamartomas) Optic glioma A distinctive osseous lesion: sphenoid dysplasia, thinning of long bone cortex … Continue reading Neurofibromatosis (NF)


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Pathology: Histology: Spindle cell tumor, densely packed, fascicular appearance. Interstitial axons (sliver impregnation or neurofilament) Immunohistochemistry: positive for= S100. Neurofilament positive interstitial axons. Findings on Investigations: Plexiform type is almost always associated with neurofibromatosis type I MRI: Widened neural foramina. Erosion of the pedicle. Usually … Continue reading Neurofibroma

Colloid Cyst:

Diagnosis: Suggested by MRI (confirmatory for clinical practice point of view), and confirmed by pathology (resection) Findings on Investigations: MRI: Foramen of Monro lesion. Nonenhancing Pathology: Histology: Lined by single layer of ciliated columnar or goblet cells. Eosinphilic colloid-like fluid. Related articles: Brain tumor,

Secondary CNS Lymphoma

Diagnosis: Suggested by MRI and confirmed by pathology (CSF, biopsy) Findings on Investigations: CT: May be normal Hydrocephalus MRI: May be normal Meningeal enhancement Multifocal parenchymal involvement Pathology: CSF & leptomeningeal involvement Usually nonHodgkin’s lymphoma   Related articles: Brain tumor, primary CNS lymphoma,

Lymphomatoid granulomatosis (LG)

Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Pathology: A type of diffuse large B cell nonHodgkin’s lymphoma B lymphocytis, granuloma involving the vessels (angiocentric & destruction of vessels) & brain parenchyma. Reactive T cells, Histiocytes EBV positive B cells Infarcts Clinical features: Affects lungs & skin, CNS, Peripheral nervous system (cranial & … Continue reading Lymphomatoid granulomatosis (LG)

Intravascular B cell Lymphoma

Synonyms: a.k.a. neoplastic angioendotheliosis a.k.a. angiocentric lymphoma a.k.a. angiotropic malignant lymphoma Diagnosis: Suggested by MRI and angiography, and confirmed by pathology (CSF, brain biopsy) Clinical features: Encephalopathy, dementia, seizures Strokes, myelopathy Can affect any organ: most commonly CNS & Skin or fever of unknown origin Pathology: NonHodgkin lymphoma, B-cell Confined to blood vessels only, doesn’t … Continue reading Intravascular B cell Lymphoma

Primary CNS lymphoma (PCNSL)

Synonyms: a.k.a. CNS lymphoma Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: CT: PCNSL: hyperdense on CT Secondary lymphoma; hyperdense on noncontrast and enhances after contrast. Variable in AIDS. MRI: Single or multiple lesions. Usually supratentorial, affecting the deep grey matter nuclei and Periventricular. Subependmal spread. Occur at grey-white matter … Continue reading Primary CNS lymphoma (PCNSL)

Hypothalamic Hamartoma

Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Clinical features: Gelastic seizures, refractory epilepsy, endocrine abnormalities Findings on Investigations: MRI: Hypothalamic mass in the floor of third ventricle Pathology: Histology: Disorganised neuroglial tissue Related articles: Brain tumor,


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Clinical features: Parinaud syndrome Hydrocephalus Findings on Investigations: MRI: Pineal mass Contrast enhancement CSF leptomeningeal metastasis can occur CSF analysis: leptomeningeal metastasis can occur Pathology: Histology: Small round blue cell tumor, high nuclear cytoplasmic ratio. Homer-Wright (around neuritic processes) & Flexner-Wintersteiner Rosettes (around lumen). Necrosis … Continue reading Pineoblastoma


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Clinical features: Parinaud syndrome Hydrocephalus Findings on Investigations: MRI: Pineal region mass Contrast enhancement Pathology: Histology: Small round blue cell tumor. Rosettes may occur. Mitosis & necrosis are rare. Immunohistochemistry: positive for= synaptophysin, NSE, neurofilament, Class III beta tubulin, chromogranin, retinal S antigen. Rarely GFAP … Continue reading Pineocytoma


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Clinical features: Parinaud syndrome Hydrocephalus Findings on Investigations: CT: Pineal region mass Calcified MRI: Pineal region mass isointense with brain Pathology: Histology: Large round blue cells, vesicular nuclei, abundant cytoplasm. With lymphocytic infiltrate. Immunohistochemisty: PLAP positive Treatment: Radiation therapy Related articles: Brain tumor,

Rathke Cleft Cyst

Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Clinical features: Visual problems, headache, Hypopituitarysm, Findings on Investigations: CT: Intrasellar or suprasellar Variable density (based on mucus content) MRI: Intrasellar or suprasellar T1: cyst is hyperintense T1 +GAD: pituitary enhances, lesion remains hyperintense Pathology: Histology: Epithelial lined cavity, cuboidal or columnar epithelium, +/-cilia, serous … Continue reading Rathke Cleft Cyst


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Clinical features: Hypopituitarism, visual field cuts, Chemical meningitis on rupture Findings on Investigations: Usually suprasellar. The following features may occur: Cysts. Calcified (rim or nodular). Enhancement (solid or nodular). CT: Calcied rim. Enhancing nodule. Hypodense cysts MRI: T1: variable intensity cysts T2: usually hyperintense PD: … Continue reading Craniopharyngioma

Pituitary adenoma

Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Clinical features: Non-secreting tumors: present with visual field defects commonly bitemporal hemianopsia. Also present with headaches or are incidentally found Hormonal syndromes with secreting tumors: amenorrhea and infertility with prolactinomas, acromegaly, Cushing’s disease with other hormones Pituitary apoplexy: Severe headache, Sudden visual loss or sudden … Continue reading Pituitary adenoma

Atypical teratoid rhabdoid tumor (ATRT)

Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: Posterior fossa > supratentorial Pathology: Histology: Small round blue cell tumor, with rhabdoid cells= eccentric nucleus with prominent nucleolus, eosinophilic cytoplasmic inclusions, Immunohistochemistry: INI1 negative (distinguishes it from choroid plexus carcinoma which is INI1 positive, but this is not a perfect test), … Continue reading Atypical teratoid rhabdoid tumor (ATRT)

Neuroblastoma, Olfactory

Synonyms: a.k.a. olfactory neuroblastoma a.k.a. esthesioneuroblastoma: Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: CT: for bone erosion, homogenous mass MRI: Mass beneath the cribriform plate in the nasal cavity, extending into the nasal sinus, orbit (via lamina papyrecea) or frontal lobe (via cribriform plate). Superior cystic component  T1: hypointense … Continue reading Neuroblastoma, Olfactory

Primitive Neuroectodermal Tumor (PNET)

If supratentorial= PNET. If cerebellar= medulloblastoma. Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: If cerebellar= medulloblastoma. If supratentorial= PNET PNET: supratentorial (frontal, parietal, occipital lobes), large, homogenous, well circumscribed. Enhance heterogeneously. Calcifications, cysts & hemorrhage are common. Minimal oedema. Medulloblastoma: midline cerebellar, may occur in cerebellar hemispheres, grow … Continue reading Primitive Neuroectodermal Tumor (PNET)


If cerebellar= medulloblastoma. If supratentorial= PNET Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: If cerebellar= medulloblastoma. If supratentorial= PNET Medulloblastoma: midline cerebellar, may occur in cerebellar hemispheres, grow into 4th ventricle with distortion of the ventricles shape, uncommonly calcify, cysts are uncommon. Minimal oedema. Moderate enhancement. PNET: supratentorial (frontal, … Continue reading Medulloblastoma

Choroid Plexus Papilloma

  Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: Interaventricular mass: fourth ventricle > lateral ventricles > third ventricle Homogenous mass, prominent flow voids (vascular), calcification Lateral ventricle trigone. In adults it occurs at the 4th ventricle. Calcification, hemorrhage may occur Enhance intensely Pathology: Pathology: Histology: Hyperplasia of bland looking … Continue reading Choroid Plexus Papilloma

Central Neurocytoma

Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: Occur anywhere in the ventricular system. Septum pellucidum, temporal & frontal horns of the third ventricle. Calcification, cystic component may occur. Variable contrast enhancement Pathology: Round cells, fibrillary background, Speckled chromatin, scant cytoplasm, Prominent vasculature sometimes, Immunohistochemistry: Positive for synaptophysin, NSE, … Continue reading Central Neurocytoma


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: Cerebellar, less commonly brainstem or spinal cord Cyst with enhancing mural nodule Other features: Associated with von Hippel-Lindau syndrome, 3p25-26 FBC: high Hb & HCT Pancreatic cysts, renal cyst Retinal hemangioblastoma Pathology: Histology: Well circumscribed, cystic with nodule Microscopically: 2 parts; … Continue reading Hemangioblastoma

Desmoplastic infantile ganglioglioma (DIG) and desmpolastic infantile astrocytoma

Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Clinical features: occur in children < 2 years old Findings on Investigations: MRI: Supratentorial, superficial cortical Large cystic lesion with solid nodule, displacing normal brain Enhancing nodule May have dural attachment Pathology: May have dural attachment Histology: Spindle cells in fascicles or storiform pattern. Large … Continue reading Desmoplastic infantile ganglioglioma (DIG) and desmpolastic infantile astrocytoma

Dysembryoplastic neuroepithelial tumor DNET

WHO grade I Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: Intracortical lesions, commonly in the temporal lobe, may have a small cystic component Clinical features: Associated with intractable seizures in some cases Pathology: Histology: Nodular or multinodular. Mucin rich cortical nodules Oligodendroglial-like areas (halos without satellitosis) and neurocytic … Continue reading Dysembryoplastic neuroepithelial tumor DNET

Gangliocytoma and Ganglioglioma

Synonyms and classification: Gangliocytoma, WHO grade I Ganglioglioma WHO grade I or II a.k.a. ganglion cell tuomur Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: May occur through out the CNS. Commonly temporal lobe. Circumscribed solid mass or cyst with mural nodule. CT: hypodense or isodense. Calcification may occur. MRI: … Continue reading Gangliocytoma and Ganglioglioma


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: Usually cystic, intraaxial, well demarcatd Enhancing Pathology: Histology: Oval nuclei, cytoplasm fibrillary or cuboidal Perivascular pseudorosette with broad processes`. Vascular hyalinisation. Immunohistochemistry: positive for GFAP, S100. Negative for Synaptophysin, neurofilament, NeuN, chromogranin Related articles: Brain tumor,


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Pathology: Histology: perivascular pseudoresettes (tumor cells surrounding a vessel), ependymal tubules ‘canals or rosettes’ (tumor cells lining central lumens) Immunohistochemistry: GFAP positive, EMA dot positivity, CD99 dot positivity Findings on Investigations: Ventricular system infratentorial (fourth ventricle) >supratentorial >spinal (lumbosacral expansion of the cord, +/-associated syrinx, … Continue reading Ependymoma


Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Pathology: Histology: small round blue nucleus, halo of cytoplasm ‘fried egg or honey comb’ appearance on formalin fixed tissue. Thin walled branching capillaries ‘chicken wire or wishbone’ appearance. Minigemistocytes, perineuronal satellitosis & Microcalcifications may occur. In higher grade; endothelial proliferation, mitosis & necrosis are present. … Continue reading Oligodendroglioma

Gliomatosis Cerebri

This is different than leptomeningeal gliomatosis: Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Pathology: Gross: enlarged brain, diffusely. Involving white matter more than grey matter, may involve any part of the neuroaxis, diffuse tumor without a single large mass Histology: infiltration of grey & white matter by undifferentiated cells. Elongated cells, forming … Continue reading Gliomatosis Cerebri

Brain Tumor

Neoplastic brain disease can be divided into primary brain neoplasms and metastatic (or secondary) brain neoplasms. Another way of classifying brain tumors is by whether they are intra-axial (within the substance of the brain) or extra-axial lesions. Furthermore, it is useful to note the general and specific locations of the tumor. Brain tumors in adults … Continue reading Brain Tumor


WHO grade IV Synonyms: formerly glioblastoma multiforme, GBM Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: MRI: Cerebral hemispheres, corpus callusum. Rarely brainstem, spinal cord Large, irregular, ring enhancing or irregular enhancing. ‘butterfly pattern’ if it spreads via the corpus callosum. Oedema. T1: low signal MRI T2,FLAIR: high signal vasogenic … Continue reading Glioblastoma

Anaplastic Astrocytoma

WHO grade III Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: Ill defined, homogenous lesion. Some enhancement within the mass, but not a ring Pathology: Histology: Nuclear atypia, mitosis, no microvascular proliferation, no necrosis Treatment: Radiotherapy Consider surgery or chemotherapy in some cases Related articles: Brain tumor, Diffuse astrocytoma,

Diffuse Astrocytoma

WHO grade II Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: Ill defined, homogenous lesion, cystic degeneration may occur. Usually non-enhancing. Enhancement suggests anaplasia CT: hypodense. May be unapparent. T2/FLAIR: high signal Pathology: Histology: Nuclear atypia, extremely rare mitosis, no microvascular proliferation, no necrosis Variants: fibrillary, gemistocytic, protoplasmic FISH: deletion … Continue reading Diffuse Astrocytoma

Pleomorphic Xanthoastrocytoma PXA

WHO grade II Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: Supratentorial. Superficial, may involve meninges i.e. meningocerebral mass. Associated with a cyst. T1: hyperintense mural nodule. Hypointense cyst Pathology: Histology: Pleomorphic cells, lipidized cells i.e. Lipid-laden astrocytes, cellular atypia, spindle cells, multinucleated giant cells. Xanthomatous (foamy/clear) astrocytes. Often, eosinphilic … Continue reading Pleomorphic Xanthoastrocytoma PXA

Subependymal Giant Cell Astrocytoma SEGA

WHO grade I Synonyms: a.k.a. SGCA Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on Investigations: CT: Near foramina of Monro, may block it, extends intraventricularly, enhances, may calcify MRI: Near foramina of Monro, may block it, extends intraventricularly, enhances Pathology: Histology: large cells resembling gemistocytic astrocytes with neuron-like nuclei & astrocyte-like … Continue reading Subependymal Giant Cell Astrocytoma SEGA

Pilocytic Astrocytoma

WHO grade I neoplasm Diagnosis: Suggested by MRI and confirmed by pathology (brain biopsy/resection) Findings on investigations: MRI: Cerebellar (commonest site). May occur in optic nerves, hypothalamus, thalamus. Brain stem-tectal plate. Ill defined cystic tumor with solid component. Occasionally without cyst. T1: low signal, enhancement of wall and solid components T2: high intensity Pathology: Histology: … Continue reading Pilocytic Astrocytoma

Fahr disease

Synonyms: a.k.a. idiopathic basal ganglia calcification Diagnosis: A combination of clinical features, imaging and other testing Clinical features: 30-60 y.o. Progressive dystonia, dysphagia, neuropsychiatric symptoms, ataxia Genetics: Autosomal dominant Chr. 14q, Findings on investigations: CT: calcification in the globus pallidus, but also occurs in putamen, caudate, dentate, thalamus and cerebral white matter Serum calcium & … Continue reading Fahr disease


A group of disorders with the following general features Neuroacanthocytosis general features Neurologic symptoms +blood smear with increased acanthocytes (spiky appearing RBCs). Note: wet preparation with a 1:1 dilution with normal saline, i.e. one drop of blood with one drop of saline. Choreoacanthocytosis: Diagnosis: Clinical features: Chorea, orofaciolingual dyskinesia Dysphagia, dysarthria, Seizures Dementia Areflexia (peripheral … Continue reading Neuroacanthocytosis

Dentatorubropallidoluysian atrophy DRPLA

Diagnosis: Genetics: Autosomal dominant DRPLA gene chr. 12. CAG repeat expansion (normal repeat number is 6-35). Protein= atrophin-1 protein. Clinical features: Chorea, ataxia, dementia, myoclonus Pathology: Gross: diffuse brain atrophy, worse in pons and cerebellum. Atrophy & discolouration of the globus pallidus, dentate nucleus, subthalamus & pontine tegmentum. Microscopic: neuronal loss of dentate nucleus with … Continue reading Dentatorubropallidoluysian atrophy DRPLA

Hypoxanthine-guanine phosphoribosyltransferase HPRT deficiency

Synonyms: Hypoxanthine-guanine phosphoribosyltransferase HPRT deficiency a.k.a. Lesch-Nyhan disease Diagnosis: Genetics: X-linked Protein= hypoxanthine-guanine phosphoribosyltransferase HPRT Clinical features: Dystonia, athetosis, Self mutilation (lip & finger biting) Mental retardation (learning disability) Severe gout, renal failure Findings on investigations: Uric acid: high Related articles: Approach to movement disorders,

Hereditary ferritinopathy and neurodegeneration with brain iron accumulation type 2 NIBA2

Synonyms: Neuroferritinopathy a.k.a. Hereditary ferritinopathy and neurodegeneration with brain iron accumulation type 2 NIBA2 Diagnosis: Genetics: Autosomal dominant Genetic: gene = FTL1, ferritin light chain gene. 460InsA mutation Clinical features: Focal dystonia, chorea, Parkinsonism. Cognitive effects occur later on. Iron studies, etc: Ferritin: low in men & post menopausal women. Normal in premenopausal women Fe … Continue reading Hereditary ferritinopathy and neurodegeneration with brain iron accumulation type 2 NIBA2

Pantathenate kinase deficiency Associated Neurodegeneration

Synonysms: Pantathenate kinase associated neurodegeneration PKAN a.k.a. Pantathenate kinase PANK deficiency a.k.a. Pantathenate kinase PANK deficiency a.k.a. Neurodegeneration with brain iron accumulation type 1 NBIA1, formerly Hallervorden-Spatz disease, rare: Diagnosis: Genetics: Sporadic or autosomal recessive PANK2 gene Chr. 20p13. Protein= pantothenate kinase (involved in coenzyme A biosythesis, panthothenate= vitamin B5) Clinical features: Childhood onset usually … Continue reading Pantathenate kinase deficiency Associated Neurodegeneration

Chronic Carbon Monoxide CO poisoning

Diagnosis: A combination of clinical features, MRI findings and carboxyhemoglobin testing Clinical features: Symmetric Parkinson like symptoms Findings on investigations: MRI: bilateral globus pallidus necrosis & lesions in the putamen, patchy white matter demyelination= Grinker myelinopathy Carboxyhemoglobin: high Pathology: Acute, not movement disorder: Cerebral oedema, Cherry red colour Chronic: Pallidal necrosis: Bilateral, asymmetrical, gross necrosis, … Continue reading Chronic Carbon Monoxide CO poisoning

Opsoclonus Myoclonus

Synonyms: a.k.a. dancing eyes dancing feet syndrome Diagnosis: This is a clinical syndrome Clinical features: Age: 18 months to 6 years. Can occur in adults Opsoclonus: rapid, involuntary, repetitive disorganised congugate eye movements in all directions of gaze. Can be confirmed by oculography: absent intersaccadic interval Investigations to consider: MRI: neuroblastoma CT: lung cancer, Hodgkins … Continue reading Opsoclonus Myoclonus

Stiff Person Syndrome

Synonyms: formerly stiff man syndrome a.k.a. Moersch-Woltmann syndrome Diagnosis: Clinical  and electrophysiological features, supplemented by antibody tests Diagnosis by exclusion: Absence of any other neurologic disease or chronic pain syndromes that could explain stiffness and rigidity. This condition is often mis-diagnosed as psychogenic dystonia Clinical features: Rigidity: Insidious onset, Limbs and axial (trunk) muscles, most … Continue reading Stiff Person Syndrome

Metoclopramide induced Akathesia

Diagnosis: Clinical features: Akathesia: inability to remain still due to an inner sense of restlessness Treatment: Stop metoclopramide Diphendyramine Consider Midazolam Related articles: Approach to movement disorders,

Tardive Dyskinesia

Diagnosis: Hyperkinetic movements due to use of dopamine receptor blocking drugs Types: Orofacial stereotypy Dystonia Treatment: Stop the offending drug Consider: Valbenazine [KINECT3 RCT] Reserpine If tardive dystonia: Anticholinergics: trihexyphenidyl Botulinum toxin injection If dystonia: Diphenhydramine Benzatropine Consider deep brain stimulation DBS of globus pallidus interna GPi Related articles: Approach to movement disorders, References: Hauser … Continue reading Tardive Dyskinesia

Genetic Dystonia

These are a group of dystonias Oppenheim’s dystonia a.k.a. dystonia musculorum deformans 1 a.k.a. DYT1: Diagnosis: Genetics: Autosomal dominant Torsin A gene, chr. 9q34 Clinical features: <26 y.o. starts as a focal dystonia (usually foot) then generalises Lubag a.k.a. X-linked dystonia Parkinsonism a.k.a. DYT3: Diagnosis: X-linked, Xq13.1, TAF1 gene, protein= transcription factor, Adults, 30y.o. (large … Continue reading Genetic Dystonia

Paroxysmal Dyskinesia

Synonyms: a.k.a. paroxysmal dystonia General points: There are two subtypes: Kinesiogenic paroxysmal dystonia Non-Kinesiogenic paroxysmal dystonia Kinesiogenic paroxysmal dystonia: Diagnosis: Precipitated by sudden movements Lasts <5 minutes, recurs up to 100/day Treatment: Carbamazepine CBZ, Phenytoin PHT Non-kinesiogenic paroxysmal dystonia (formerly paroxysmal dystonic choreoathetosis, Mount–Reback syndrome): Diagnosis: This condition is DYT8 a form of genetic dystonia … Continue reading Paroxysmal Dyskinesia

Meige Syndrome

Diagnosis: This is a clinical diagnosis Clinical features: Blepharospasm +orofacial dyskinesia (includes tongue & jaw) Difficulty chewing Related articles: Approach to movement disorders,

Generalised Dystonia or Segmental Dystonia

Diagnosis: Clinical features: Segmental: to adjacent regions Mutifocal: nonadjacent regions Hemidystonia: ipsilateral arm & leg Generalised: leg +trunk +another region Trial of levodopa, 2 months long to rule out dopa responsive dystonia. Treatment: Trial of levodopa, 2 months long. This should be tried in all childhood onset dystonias Anticholinergics: e.g. Trihexyphenidyl Others: Clonazepam, Baclofen or … Continue reading Generalised Dystonia or Segmental Dystonia

Focal Dystonia

Diagnosis: Clinical Focal dystonia: i.e. dystonia involving 1 region Types: Blepharospasm: involuntary bilateral eye closure Oromandibular dystonia Spasmodic dysphonia Cervical dystonia: Spasmodic (intermittent) or sustained Torticollis: turned/rotated Retrocollis: extended Anterocollis: flexed Laterocollis: tilted Focal hand dystonia Task specific dystonia: Writers cramp (graphospasm), piano players cram, guitar players cramp, golf, running Investigations to consider: Consider: MRI … Continue reading Focal Dystonia

Tourette’s syndrome

Synonyms: Gilles de la Tourette’s syndrome Diagnosis: Clinical criteria: Onset < 21 y.o. Lasts >1 year. Multiple motor tics. At least 1 vocal tick. Fluctuating course. Corprolalia is not necessary for diagnosis Consider associated: Attention deficit hyperactivity disorder ADHD Obsessive compulsive disorder OCD Treatment: Educate patient, family members, teachers. Decide on if treatment is warranted … Continue reading Tourette’s syndrome

Periodic Alternating Nystagmus PAN

Diagnosis: Primary position of gaze: Horizontal jerk nystagmus to one direction for 2 minutes, this then changes/alternates to the opposite direction every 2 minutes May be associated with Anti-GAD antibodies Clinical features: Oscillopsia Nystagmus Findings on investigations: MRI: hemorrhage or stroke of the nodulus of the cerebellum, Chiari-Malformation, Arachnoid cyst, Multiple sclerosis Anti-GAD antibody Treatment: … Continue reading Periodic Alternating Nystagmus PAN

Anti-GAD antibodiy associated progressive cerebellar ataxia

Diagnosis: Clinical features plus anti-GAD antibodies Clinical features: Progressive ataxia Findings on investigations: Anti-GAD antibody: positive Related articles: Approach to movement disorders,

Paraneoplastic Cerebellar Degeneration

Diagnosis: A combination of clinical features, identification of underlying cancer and occasionally other tests Clinical features: Symmetric subacute progressive cerebellar ataxia with dysarthria & nystagmus Pathology: Histology: massive loss of Purkinje cells. Dentate nucleus: Pallor of myelin fleece (amiculum). Sometimes mononuclear perivascular infiltrates or microglial nodules Findings on investigations: Antibodies: anti-Yo a.k.a. anti-PCA-1 (ovarian & … Continue reading Paraneoplastic Cerebellar Degeneration

Fragile X Tremor Ataxia syndrome

Diagnosis: Genetic testing: expansion of CGG repeat on FMR1 gene on chr. X. 55-200 repeats = premutation range, associated with tremor/ataxia syndrome and premature ovarian failure >200 repeats = Fragile X syndrome Findings on investigations: MRI: T2 white matter hyperintensities in the middle cerebellar peduncles or brain stem. Cereberal white matter hyperintensities and atrophy may … Continue reading Fragile X Tremor Ataxia syndrome

Episodic Ataxia type 2

Genetics: Autosomal dominant Ca++ CANA1A chr. 19p13.1 Clinical features: 2nd decade. Paroxysmal cerebellar ataxia Lasts hours: Vertigo, diplopia, nystagmus Progressive signs Associated with absence seizures in some Findings on investigations: MRI: vermian atrophy Treatment: Responds to acetazolamide Related articles: Approach to movement disorders,

Episodic Ataxia type 1

Genetics: Autosomal dominant Kva1.1 KCNA1 chr. 12q13 Clinical features: Paroxysmal cerebellar ataxia, seconds-minutes Triggers: exertion, stress, startle Associated with: Myokymia/neuromyotonia Cramps Findings on investigations: Electrophysiology/Pathogenesis: EMG: spontaneous discharges (Myokymia/neuromyotonia) Treatment: Acetazolamide or Carbamazepine CBZ Related articles: Approach to movement disorders,

Spinocerebellar Ataxias

Synonyms: Spinocerebellar ataxias (SCAs) a.k.a. spinocerebellar degeneration, formerly olivopontocerebellar ataxia (OPCA) Spinocerebellar ataxias (SCAs) in General: This  is a group of disorders characterized by ataxia and other findings such as hypotonia. The various subtypes are outlined below Clinical features: Hypotonia and ataxia MRI: Atrophy of Cerebellum & pons SCA1: Diagnosis: Autosomal dominant CAG repeat, ataxin-1 … Continue reading Spinocerebellar Ataxias

Ataxia with Vitamin E Deficiency

Synonyms: Ataxia with vitamin E deficiency (AVED) Diagnosis: Genetic testing and vitamin E levels Genetics: Autosomal recessive Protein= alpha-tocopherol transfer protein Findings on investigations: Vitamin E levels: low Related articles: Approach to movement disorders,

Friedreich’s Ataxia

Diagnosis: Genetics: Autosomal recessive Frataxin gene chr. 9. Protein= Frataxin. GAA nucleotide repeat (normal repeat number is 6-27). Compound heterozygotes occur in 5%. Clinical features: Ataxia & dysarthria Areflexia, extensor plantars Hammer toes arched foot, scoliosis Pathology: Gross: atrophy of spinal cord. Grey discolouration of posterior & lateral aspects of the spinal cord. Small sensory … Continue reading Friedreich’s Ataxia

Gluten Ataxia

Synonyms: Gluten ataxia a.k.a. ataxia associated with Coeliac disease antibodies Diagnosis: A combination of clinical features and testing for coeliac disease Clinical features: Ataxia +Coeliac disease antibodies: anti-TTG (especially anti-TTG6), anti-Endomysial antibody +exclusion of other causes Findings on investigations: MRI: cerebellar atrophy, T2 white matter hyperintensities Related articles: Approach to movement disorders,

Acute Post-Infectious Cerebellitis

Diagnosis: This is diagnosed by a combination of clinical features, imaging finding and sometimes associated laboratory tests Clinical features: Prodrome e.g. Upper respiratory tract infection Then Headache Then cerebellar ataxia Then improvement Findings on investigations: MRI +GAD: Normal, Then cerebellar enhancement of folia & hemispheres, swelling of hemispheres, tonsillar ectopia Then mild cerebellar atrophy, resolution … Continue reading Acute Post-Infectious Cerebellitis

Progressive Ataxia and Palatal Tremor

Synonyms: PAPT= Progressive ataxia and palatal tremour Diagnosis: This is a diagnosis of exclusion Clinical features: Soft ear clicks heard by patient & examiner Symmetrical palatal tremour (levator veli palatini muscle) Ataxia Findings on investigations: MRI, MRA: Absence of lesion in dentato-rubro-olivary pathway (Guillain-Mollaret triangle) which lies in the brainstem tegmentum Hypertrophic olivary degeneration Atrophy of … Continue reading Progressive Ataxia and Palatal Tremor

Oculopalatal Tremor

Synonyms: OPT, formerly oculopalatal myoclonus a.k.a. palatal tremour formerly palatal myoclonus Diagnosis: Clinical diagnosis Clinical features: Soft ear clicks heard by patient & examiner. Oscillopsia Symmetrical palatal tremour (levator veli palatini muscle) +Ocular nystagmus: pendular (same speed in both phases), usually vertical (may be tosional) & sometimes horisontal. May be bilateral or unilateral i.e. dissociated. … Continue reading Oculopalatal Tremor

Rubral Tremor

Synonyms: Holmes tremor Diagnosis: This is a clinical diagnosis in the correct clinical context (damage to the midbrain) Clinical: Mainly unilateral tremor, low frequency (3–5 Hz) Occurs at rest, in posture and during movement Exacerbation by goal-directed movements. Disappears during sleep Findings on investigations: MRI: lesions in brain stem, cerebellum or thalamus Treatment: Consider Levetiracetam … Continue reading Rubral Tremor

Cerebellar Tremor

a.k.a. kinetic tremor Diagnosis: Clinical: Intension tremor due to cerebellar lesions, or lesions in the brainstem. Midbrain tremors (red nucleus, rubral tremors) occur at rest & intention. Treatment: None are satisfactory, try: Carbamazepine CBZ, buspirone, glutithimide, isoniazid Related articles: Approach to movement disorders,

Orthostatic Tremor

Diagnosis: Clinical plus neurophysiology Clinical: Tremor in the legs upon standing. Sometimes also involves the hands EMG: Rhythmic discharges High frequency discharges: 16-18 Hz Treatment: 1st line: Clonazepam 2nd line: Propranolol, primidone, Gabapentin GBP, phenobarbitone Related articles: Approach to movement disorders,

Wilson's disease

Synonyms: a.k.a. hepatolenticular degeneration: Diagnosis: Slit lamp examination: Kayser Fleischer rings Golden Brown Corneal deposits Neurological: wing-beathing tremor & facial dystonia (sardonic smile), cognitive deficits, neuorpsychiatirc symptoms Ceruloplasmin: low, <20 mg/dL 24 hr Urinary copper excretion: increased >100 micrograms MRI: T2: Increased signal (but variable) in striatum, Midbrain, Pons, dentate nucleus, white matter lesions T1: … Continue reading Wilson's disease

Neurofilament inclusion body disease NIBD

Diagnosis: A combination of clinical and MRI Clinical: Age <65yo Parkinsonism: Rigidity, bradykinesia, falls Dopamine resistant Cortical features: Hand clumsiness, apraxia, language dysfunction, Mute, MRI: Frontal atrophy, caudate atrophy, temporal atrophy, Pathology: Gross: frontal atrophy, caudate atrophy, Nigral pallor, Superficial Spongiosis in frontal lobes, Purkinje cell loss Intraneuronal inclusions (cytoplasmic) in frontal lobes, see below … Continue reading Neurofilament inclusion body disease NIBD

Argyrophilic grain disease AGD

Diagnosis: A debatable neurodegenerative condition. Considered a tauopathy. Pathology: Argyrophilic grains (silver staining grains by Gallyas silver iodide method) in neuropil of the cortex of elderly patients with cognitive symptoms. Shape: spindle shaped, rod-like, button-like or round bodies. Ballooned neurons (a nonspecific finding, silver negative) & coiled bodies in oligodendrocytes (a nonspecific finding) also occur. … Continue reading Argyrophilic grain disease AGD

Corticobasal Degeneration

Synonyms: a.k.a. Cortical basal ganglionic degeneration CBGD formerly corticodentatonigral degeneration with neuronal achromasia a.k.a. corticonigral degeneration: Diagnosis: Clinical: Cortical signs: apraxia, visuospatial impairment, executive dysfunction, language dysfunction, spared memory function. +Basal ganglia signs: asymmetric rigidity, dystonia, myoclonus, alien hand, Relative Sparing of memory Pathology: Gross: Perisagittal atrophy of frontal & parietal lobes. Substantia nigra pallor … Continue reading Corticobasal Degeneration

Progressive Supranuclear Palsy

Synonyms: a.k.a. PSP, a.k.a. -Richardson-Olszewski syndrome Diagnosis: Clinical: Symmetric parkinsonism, vertical gaze palsy, eyelid opening apraxia, axial rigidity (axial dystonia), retrocollis, dementia (executive dysfunction, impaired abstraction & planning, relatively preserved memory), pseudobulbar palsy, pseudobulbar affect, Clinically two syndromes: Richardson syndrome: postural instability with falls, supranuclear vertical gaze palsy, cognitive deficits/dementia. PSP-Parkinsonism: unilateral tremor, transient levodopa … Continue reading Progressive Supranuclear Palsy

Multiple System Atrophy

Synonyms: formerly Shy-Drager syndrome/Striatonigral degeneration, formerly included under olivopontocerebelar atrophy OPCA Diagnosis: This is based on clinical features supported by consistent investigations Clinical features: Parkinsonism +other features: Ataxia Early falls forward Autonomic failure: Othostatic hypotension, syncope Impotence, urinary retention, constipation Axial rigidity Laryngeal stridor Hypometric saccadic eye movements Coat hanger sign: a sensation of being … Continue reading Multiple System Atrophy

Post-Encephalitic Parkinsonism

Synonyms: Encephalitis lethargica a.k.a. postencephalitic parkinsonism a.k.a. Von Economo encephalitis: Diagnosis: Clinical: Prodrome: pharyngitis Subacute sleep disturbance (hypersomnolence, reversal of diurnal sleep pattern or insomnia), ophthalmoparesis, lethargy Followed by: Parkinsonism, dyskinesia, oculogyric crisis, neuropsychiatric symptoms and central respiratory abnormalities Pathology: Midbrain and basal ganglia: lymphocyte (predominantly plasma cell) infiltration Investigations to consider: CSF: Oligoclonal bands … Continue reading Post-Encephalitic Parkinsonism

Serotonin Syndrome

Diagnosis: Clinical features: Hyperthermia, muscle rigidity, abdominal cramping, hypertension, myoclonus, agitation, coma, life-threatening Investigations to consider: FBC, metabolic panel, creatinine, CK Treatment: Discontinue the drug Hyperthermia: Active cooling, entubation & muscle relaxants Lorazepam intravenously 5HT2 antagonist: cyproheptadine orally If severe: intensive care & observation Related articles: Approach to movement disorders, Neuroleptic malignant syndrome,

Neuroleptic Malignant Syndrome

Diagnosis: Clinical: Hyperpyrexia +autonomic instability + muscle rigidity +tachycardia +fluctuation of consciousness Investigations to consider: FBC: leukocytosis, LFTs: AST & ALT are high, U&E, creatinine Creatine kinase: high,, plasma myoglobin: high Urinalysis for myoglobin: myoglobinuria Treatment: Discontinuing the offending drug/drugs Cooling Dantrolene Dopamine agonist e.g. bromocriptine Related articles: Approach to movement disorders, Serotonin syndrome,

Ophthalmoplegic "Migraine"

Diagnosis: Likely not a form of migraine but rather demyelination Clinical: Repeated episodes of ophthalmoplegia during or after a migranous headache +MRI: may show changes within the affected nerves III, IV, VI No other lesions Related articles: Approach to diplopia,

Cerebral Palsy

The term cerebral palsy is a broad term for multiple conditions that share in common that there is a non-progressive disorder of power, movement or posture due to damange of the immature brain. Diagnosis: Clinical: A non progressive disorder of power, movment or posture due to damage of the immature brain Patients may have a … Continue reading Cerebral Palsy

Dolichoectasia of intracranial arteries

Synonyms and related terms: Vertebrobasilar dolichoectasia, Vertebral artery dolichoectasia, basilar artery dolichoectasia, internal carotid artery dolichoectasia Diagnosis: Clinical: Asymptomatic, or nerve palsies e.g. XII, Associated with longstanding uncontrolled hypertension or family history CTA: Ectatic and elnongated intracranial arteries, may be confused with fusiform aneurysms, may be associated with aneurysm in the same patient, Typically in … Continue reading Dolichoectasia of intracranial arteries

Vertebral Artery Stenosis, Extracranial

This section refers to extracranial vertebral artery stenosis due to atherosclerotic disease Diagnosis: Must exclude other etiologies of stroke: including intracranial atherosclerotic disease Catheter angiography: Gold standard test Allows accurate determination of degree of stenosis and collateral pathways Allows determination of intracranial disease MRA CTA Ultrasound: is if insufficient sensitivity to exclude the diagnosis Treatment: … Continue reading Vertebral Artery Stenosis, Extracranial

Vertebral Artery Stump Syndrome

Diagnosis: Ongoing ischemic events in the territory supplied by the vertebral artery despite occlusion of the vertebral artery Must be differentiated from intracranial atherosclerotic disease (ICAD), small vessel disease and other competing stroke mechanisms Pathophysiology: Emboli travel to the posterior circulation in the distribution of the affected vertebral artery via collaateral pathways. Treatment: Medical therapy: … Continue reading Vertebral Artery Stump Syndrome

Carotid Stump Syndrome

Diagnosis: Ongoing ischemic events in the territory supplied by the internal carotid artery despite occlusion of the internal carotid artery Must be differentiated from intracranial atherosclerotic disease (ICAD), small vessel disease and other competing stroke mechanisms Pathophysiology: Emboli travel to the ipsilateral brain or retina in the distribution of the affected internal carotid artery via … Continue reading Carotid Stump Syndrome

Ischemic Stroke with Patent Foramen Ovale

This section will summarize ischemic stroke with Patent foramen ovale (PFO) or atrial septal aneurysm Diagnosis: This Patent foramen ovale is associated with cryptogenic stroke, but is not the major cause of cryptogenic stroke. Consider this potential etiology in patients with non-lacunar stroke after investigations for intracranial atherosclerosis, extracranial atherosclerosis, atrial fibrillation (including long term … Continue reading Ischemic Stroke with Patent Foramen Ovale

Varicella Zoster Virus VZV vasculopathy

Diagnosis: Clinical: large artery or small vessel ischemic stroke, recurrent, protracted course. Rash may be absent or occur months before MRI, CT: large artery or small vessel ischemic stroke, typically at grey-white junction. Imaging is sensitive but not specific Anti-VZV IgG & VZV PCR: IgG is more sensitive for VZV vasculopathy, also reduced serum/CSF ratio … Continue reading Varicella Zoster Virus VZV vasculopathy

Spinal epidural venous engorgement of pregnancy

Diagnosis: Clinical: Acute spastic monoplegia or paraplegia MRI: vascular congestion (prominent paravertebral & epidural blood vessels), T2 high signal in cord. Compression of IVC by uterus. Resolution of findings after deliver. Related articles: Myelopathy,

Diffuse Axonal Injury

Diagnosis: Neuroimaging +Clinical features Clinical features: Coma after head trauma: low GCS <8, with or without features to suggest structural cause (dilated pupills, disconjugate gaze, asymmetric posturing) Raise intracranial pressure (ICP ) often occurs Neuroimaging: CT: May be normal May show petechial hemorrhages in the whitematter (corpus callosum, corona radiata, cerebral peduncles) May show diffuse … Continue reading Diffuse Axonal Injury

Cerebral Contusion

Diagnosis: CT: Cerebral edema (hypodensity on CT) in the cortex or lobe at  the site of injury or opposite location (counter-coup) or distant site where impact occurs at areas of the skull Hemorrhage (hyperdensity on CT) within the areas of contusion are typical. They involve the cortex and extend subcortically to a variable extent Frontal … Continue reading Cerebral Contusion

Subdural Hematoma

Synonyms: Subdural haematoma Diagnosis: CT: Crescent shaped, diffuse covering a large part of the hemisphere Can be biconvex in shape Can be of mixed density: e.g. Fluid-fluid level Cross suture lines but not the midline Variation with time: Acute, hyperdense, homogenous Middle, isodense with brain Chronic: hypodense Acute on chronic: heterogenous, fluid-fluid levels Pathology: Acute: … Continue reading Subdural Hematoma

Epidural Hematoma

Synonyms: Extradural hematoma Diagnosis: CT or MRI: Biconvex shape a.k.a. ‘lentiform’, usually over the temporal lobe Can cross the falx, tentorium, can cross the midline, but doesn’t cross the suture lines Associated with skull fracture Clinical features: Usually there is a history of trauma Often the patient is knocked unconscious with the initial trauma. They … Continue reading Epidural Hematoma


Diagnosis: Clinical Classification: Grade 1: Transient confusion; no loss of consciousness; concussion symptoms clear in less than 15 minutes. Grade 2: Transient confusion; No loss of consciousness; concussion symptoms or mental status abnormalities last longer than 15 minutes. Grade 3: Any loss of consciousness, either brief (seconds) or prolonged (minutes). Treatment: Return to play (quick … Continue reading Concussion

Traumatic Brain Injury

Synonyms and related terms: Head trauma a.k.a. head injury a.k.a. traumatic brain injury TBI Diagnosis: Clinical With or without neuroimaging: CT more commonly than MRI, Classification, the Glasgow coma scale GCS was designed for this: Mild: GCS 13-15 Moderate: GCS 9-12 Severe: GCS = or <8 Critical: GCS 3-4 Treatment: If mild: Consider discharge or … Continue reading Traumatic Brain Injury

Subcortical Arteriosclerosis Encephalopathy

Now considered a subtype of Subcortical Vascular Dementia when cognitive dysfunction is present. It is the result of longstanding small vessel disease, particularly due to uncontrolled hypertension. Synonyms: Binswanger disease a.k.a. subcortical arteriosclerosis encephalopathy: Diagnosis: MRI T2/FLAIR: subcortical white matter hyperintensities in confluent areas (initially multifocal), more prominant periventricularly, usually with evidence of previous lacunar … Continue reading Subcortical Arteriosclerosis Encephalopathy

Primary Angiitis of the Central Nervous System

Synonyms: Primary angiitis of the central nervous system PACNS a.k.a. Granulomatous angiitis of the CNS GANS a.k.a. isolated CNS vasculitis Diagnosis: Brain +Meningeal biopsy: 1 cm wedge biopsy with meninges, grey & white matter Small or medium sized vessels. Parenchymal or meningeal Transmural destruction. Granulomatous (multinucleated cells) or lymphocytic infiltrate. Sometime macrophages. Intimal proliferation may … Continue reading Primary Angiitis of the Central Nervous System

Reversible Cerebral Vasoconstriction Syndrome

Synonyms: Reversible cerebral vasoconstriction syndrome RCVS a.k.a. Call-Fleming syndrome a.k.a. benign angiopathy of the CNS a.k.a. thunderclap headache with vasoconstriction Diagnosis: Clinical: Female >Male, thunderclap headache with out without neurological symptoms. Hemiplegia, visual field defects, May be postpartum +Imaging Findings on investigations: CT: infarcts usually posterior/watershed or hemorrhagic transformation, no SAH MRI: infarcts usually posterior/watershed … Continue reading Reversible Cerebral Vasoconstriction Syndrome

Cervical Artery Dissection

Synonyms: Cervical artery dissection: Internal Carotid artery dissection ICAD a.k.a. carotid dissection AND Vertebral artery dissection VAD Diagnosis: A combination of MRI dissection protocol and catheter angiography is best Findings on Investigations: MRI axial T1: False lumen= intermural hematoma (high signal, appears after 48hrs) compressing the true lumen (signal void). [274] Conventional spin echo MR: … Continue reading Cervical Artery Dissection

Radiation Vasculopathy

Diagnosis: MRI: Infarcts Enhancing mass lesion Cavernous marlformations Angiogram/Catheter angiography: Stenosis in MCA, ICA Can also cause accelerated atherosclerosis in the extracranial internal carotid artery Treatment: Depends on presentation: Enhancing mass, typically treated with steroids Infarcts are treated with antiplatelets, but data is limited Extracranial accelerated atherosclerosis is treat with antiplatelets, risk factor control and … Continue reading Radiation Vasculopathy

Fibromuscular Dysplasia

Synonyms: Fibromuscular dysplasia FMD, Diagnosis: Catheter angiography: Affects: extracranial vessels e.g. carotid artery Dilated portions (larger than normal parent vessel) & stenotic portions +/-Pseudoaneurysm Type 1: ‘string if pearls’ beaded appearance Type 2: tubular stenosis (focal or multifocal) Type 3: limited to part of the arterial wall False negatives with MRA, CTA and ultrasound but … Continue reading Fibromuscular Dysplasia

Intracranial Atherosclerotic Disease

Synonyms: Intracranial atherosclerotic disease ICAD a.k.a. Intracranial stenosis & intracranial atherosclerosis Diagnosis: Catheter angiography: WASID intracranial stenosis criteria: 50% stenosis by WASID criteria: Measure the diameter of the residual lumen Measure the normal reference diameter (one of the following in descending order of preference): 1 Same artery proximal to the stenosis 2 Same artery distal … Continue reading Intracranial Atherosclerotic Disease

Carotid Artery Stenosis, Extracranial

This section discusses extracranial internal carotid artery stenosis due to atherosclerotic disease. Diagnosis: Catheter angiography DSA digital subtraction angiography: Gold standard test NASCET measurement: N= narrowest diameter of residual lumen D= diameter of ICA well beyond the bulb Percentage stenosis= (1-N/D) X 100 Useful for: Suspected Total occlusion, Difficult anatomy, Fibromuscular dysplasia, Dissection, Disconcordant tests, … Continue reading Carotid Artery Stenosis, Extracranial

Cardioembolic Stroke

Diagnosis: Ischemic stroke with cardiac source found on investigations. Treatment: No use for anticoagulation  if not cardioembolic [TOAST] Choice of anticoagulant: Apixaban Dabigatran Warfarin orally, goal INR= 3.0-4.0 monitor every 2 weeks. Start Warfarin therapy without bridging [retrospective review] Other options: edoxaban, rivaroxaban Anticoagulate if: Atrial fibrillation [EAFT] Prosthetic valve: If recurrent on anticoagulation add … Continue reading Cardioembolic Stroke

Small Vessel Disease

This section will cover ischemic stroke due to small vessel disease Synonyms: Microangiopathic stroke a.k.a. microangipathic infarct ~Lacunar infarct Diagnosis: Clinical lacunar/thalamic syndrome: +HTN or DM +negative cardiac evaluation +negative large artery disease evaluation Note that cardiac embolism and large artery disease can cause imaging features consistent with lacunar infarcts Extensive work up is still … Continue reading Small Vessel Disease

Transient Ischemic Attack

Diagnosis: Sudden neurological focal deficit of vascular origin lasting <24 hrs (usually lasts <1 hr), with normal diffusion weighted MRI (DWI). PWI: may show decreased perfusion. Investigations to Consider: Blood tests: FBC, Coagulation screen, Blood Glucose, Blood chemistry panel, Fasting: Cholesterol, Lipids, glucose ESR: vasculitides, giant cell arteritis. Consider Homocystein, vasculitic screen, thrombophilia screen Extracranial … Continue reading Transient Ischemic Attack

Cerebral Amyloid Angiopathy

Patholgy: Brain Biopsy: Involves the cortex & overlying meninges, sparing the deeper structures. Histology: Congophilic angiopathy: amyloid in medium & small sized arteries. Dyshoric angiopathy: amyloid leaking from capillaries. Media & advantitia infiltration. H&E: eosinophilic acellular amorphous material (media & adventitia). Sometimes double barrel vessels (loss of smooth muscle & preservation of endothelium). Congo red … Continue reading Cerebral Amyloid Angiopathy

Cavernous Malformation

Synonyms: a.k.a. Cavernous hemangioma a.k.a. Cavernous angioma a.k.a. cavernoma Pathology: Dilated thin walled veins, without intervening brain tissue, surrounding gliosis & hemosiderin, no elastin in the walls Diagnosis: MRI: TI, T2 & FLAIR: Heterogenous mass (blood at different ages) with high signal on TI, T2 & FLAIR, low signal rim (hemosiderin) on T2 & FLAIR … Continue reading Cavernous Malformation

Spinal Vascular Lesions

Classification: Neoplastic vascular lesions: Hemangioblastoma Cavernous hemangioma Spinal aneurysms, rare Spinal Arteriovenous fistula, AVF Extradural Intradural: a.k.a. Foix-Alajouanine Ventral intradural: A. Small shunt B. Medium shunt C. Large shunt Dorsal intradural: A. single feeder B. multiple feeders Spinal Arteriovenous malformation AVM: Extradural-intradural Intradural: Intramedullary: Compact Diffuse Conus medullaris     Spinal Arteriovenous Fistula, spinal-AVF: Spinal … Continue reading Spinal Vascular Lesions

Capillary telangiectasia

Diagnosis: Clinical: Usually an incidental finding, very rarely [case reports] of bleeding. MRI: Pons ~3cm diameter T1 +contrast: Nodular enhancement after contrast Gradient echo GRE: hypointense, T2 isointense CT: invisible Angiography: Usually nothing is visible Pathology: Pons is the commonest location Microscopic Ectatic thin walled vascular channels (Capillaries) with interspersed normal appearing brain matter. Usually, … Continue reading Capillary telangiectasia

Sinus pericranii

Diagnosis: Clinical: Scalp mass that increases with valsalva or lying down & reduces with standing CT: Focal bone defect may be present Extracranial venous malformation that enhances heterogenously Cortical varix that strongly enhances CTV shows this well MRI: T1, T2: signal based on flow Contrast: Cortical Varix enhances well. Extracranial Venous malformation enhances heterogeneously MRV … Continue reading Sinus pericranii

Developmental Venous Anomaly

Synonyms: a.k.a. Venous malformations a.k.a. venous angioma Diagnosis: MRI: Linear structures with flow voids Dilated medullary veins: Around the ventricles, transcerebral course One large vein may drain into dural sinus or deep vein Enhance with contrast: caput medusae or umbrella shaped Features of associated cavernous malformation may be present Catheter Angiography: Normal arteries in size … Continue reading Developmental Venous Anomaly

Vein of Galen malformation

Synonyms: a.k.a. vein of Galen aneurysm a.k.a. Galenic varix   General points: This is a type of direct arteriovenous fistula AVF. It’s a misnomer because it involves the Median prosencephalic vein of Markowski. It is not an AVM because there is no nidus. It is not a dural arteriovenous fistula because it does not involve … Continue reading Vein of Galen malformation

Vertebral arteriovenous fistula

This section refers to Vertebral arteriovenous fistula (without dural involvement): Diagnosis: Clinical: Vertebrobasilar insufficiency, lower cranial nerve compression, neck pain, or asymptomatic Usually post trauma. Spontaneous fistula occur in fibromuscular dysplasia and neurofibromatosis. i.e. usually a complication of dissection Catheter angiography DSA: Arterial supply: Vertebral artery directly fills veinous plexus. Fistula point is usually at … Continue reading Vertebral arteriovenous fistula

Carotid Cavernous Fistula

Carotid cavernous fistulas are a type of dural arteriovenous fistula that involves the cavernous sinus. There are two types of carotid cavernous fistula (CCF): Direct carotid-cavernous fistula Indirect carotid-cavernous fistula   Classification (by catheter angiography): Barrow Type A i.e. direct CCF: direct ICA to Cavernous sinus shunt. i.e. no dural arterial branches are involved Type … Continue reading Carotid Cavernous Fistula

Dural Arteriovenous Fistula, Cranial

Clinical features: Wide range including: asymptomatic, pulsatile tinnitus, headache, cranial nerve palsy, cognitive deficits, hydrocephalus, focal deficits, seizures\ Pulsatile tinnitus, pulsatile exophthalmos Cranial neuropathy Encephalopathy, dementia, Parkinsonism In neonates/infants: heart failure Diagnosis: Catheter Angiogram: Use superselective catheterisation of 4 vessels, +external carotid Abnormal arteries and veins with shunting contained entirely within the dura (dural leaflets) … Continue reading Dural Arteriovenous Fistula, Cranial

Arteriovenous Malformations

Findings on Investigations: CT: Tangle of blood vessels: Serpentine or punctate high density on noncontrast Enhance with contrast Calcification may occur, hemorrhage may occur Hydrocephalus may occur with Vein of Galen malformation CTA: Arteries & draining veins are visible well, but angiography is still necessary MRI: Localises the lesion well. T1: curvilinear vessels T2: curvilinear … Continue reading Arteriovenous Malformations


Synonyms: Posterior communicating artery infundibulum: Diagnosis: CTA, MRA, catheter angiography: <3mm out pouching with an artery arising directly from the apex. Most commonly Posterior communicating artery Must be distinguished from very small aneurysms (=or<3mm) based on morphology

Cerebral Pseudoaneurysms

Subtypes: These can be Intracranial or extracranial Intracranial Pseudoaneurysm (Cerebral Pseudoaneurysm) Extracranial cervical artery pseudoaneursym (cervical pseudoaneurysm): Diagnosis: Focal dilation of a vessel wall that is not outlined by the layers of normal arterial wall. Usually, a hematoma that communicates with the vessel lumen. CT: Hematoma adjacent to vessel. Enhancing focus within a hematoma. CTA: … Continue reading Cerebral Pseudoaneurysms

Blister Like Pseudoaneurysm

Synonyms: Blood blister-like aneurysm a.k.a. blister-like pseudoaneurysm a.k.a. trunk aneurysm Pathology: Atherosclerosis with ulceration & hematoma A small defect in the vessel wall covered only with overlying fibrous tissue Atherosclerosis in parent vessel Diagnosis: Catheter Angiography: Small lateral wall bulge (asymmetric i.e. only one side of the lateral wall), hemispherical in shape Usually <10mm May … Continue reading Blister Like Pseudoaneurysm

Cerebral Aneurysms, Fusiform

Subtypes: There are two main subtypes: Non-atherosclerotic fusiform cerebral aneurysms (some authors include dissecting aneurysms here) Atherosclerotic fusiform cerebral aneurysms These are different from saccular cerebral aneurysms These are discussed in the two sections below: Non-Atherosclerotic fusiform cerebral aneurysms: Diagnosis of non-atherosclerotic fusiform aneurysms: Catheter Angiography: Long segment fusiform dilatation in absence of atherosclerosis, +ectatic … Continue reading Cerebral Aneurysms, Fusiform

Cerebral Aneurysms, Saccular

Please see other articles for fusiform cerebral aneurysms Synonyms: Saccular Intracranial aneurysms, Saccular Cerebral aneurysms, saccular aneurysms Diagnosis: Catheter angiography is the gold standard MRA and CTA can also be used as good screening tests Clinical features: Asymptomatic SAH signs and symptoms Occulomotor nerve palsy Trigeminal neuralgia Visual field cut (optic nerve compression) Cavernous sinus … Continue reading Cerebral Aneurysms, Saccular

Superficial Siderosis

 Synonyms: Central nervous system siderosis: Diagnosis: MRI: T2: dark outlining similar to GRE of all affected structures T2 gradient echo GRE: dark outlining to cerebellum, cerebellar folia, VIII cranial nerve & meninges & rest of the brain or spinal cord FLAIR: dark outlining similar to GRE of all affected structures T1: high signal on CNS … Continue reading Superficial Siderosis

Perimesenchphalic Subarachnoid Hemorrhage

Diagnosis: CT or MRI: blood in CSF space around the midbrain i.e. peri-mesencephalic. Usually in prepontine cistern or quadrageminal cistern. +Catheter Angiography: that excludes any cause of SAH. Especially posterior circulation aneurysm. +absence of trauma DDx. Aneurysmal subarachnoid hemorrhage due to ruptured posterior  inferior cerebellar artery (PICA) aneurysms 7% of Posterior circulation aneurysms may present … Continue reading Perimesenchphalic Subarachnoid Hemorrhage

Post-Anoxic Myoclonus

Synonym: Lance-Adams myoclonus Diagnosis: This is a clinical diagnosis: Delayed action-induced myoclonus, this occurs in the recovery phase of anoxic brain injury This is different from generalized myoclonic status epilepticus which occurs soon after anoxic injury Treatment: Valproic acid Related articles: Approach to movement disorders,

Anoxic Brain Injury

Synonyms: Global cerebral ischemia a.k.a. global/diffuse cerebral hypoxia ischemia a.k.a. hypoxic ischemic encephalopathy a.k.a. Postanoxic Encephalopahty Diagnosis: Clinical features with or without MRI Clinical features: Coma after pulseless cardiac arrest or after significant hypoxia Episode of brain anoxia/global ischemia. Myoclonic status epilepticus may occur (may involve face, trunk, limbs) Findings on investigations: MRI: T2/FLAIR hyperintensity … Continue reading Anoxic Brain Injury

Posterior Reversible Leukoencephalopathy Syndrome PRES

Synonyms: Reversible posterior leukoencephalopathy syndrome RPLS Diagnosis: CT: Hypodensity in affected areas, MRI is better. MRI: T2: Hyperintensity in the occipital and sometimes parietal areas bilaterally. Involves the white matter and sometimes the grey matter. Other affected areas; basal ganglia, cerebellum, brain stem, frontal lobes. Areas usually spared: calcarine cortex, paramedian occipital lobe DWI: hyperintense … Continue reading Posterior Reversible Leukoencephalopathy Syndrome PRES

Degos disease

Synonyms: Malignant atrophic papulosis Diagnosis: Clinical: Skin, brain & bowel vasculitis Skin: initially red papules then, umbilicated papules, +white centre & telangiectatic rim Bowel: GI bleed, bowel perforation MRI: Infarcts T2 hyperintensities, +small hemorrhagic areas T1 +GAD: dural enhancement may occur Cather Angiogram/angiography: Vasculitis features Peripheral aneurysms Also stenosis in GI arteries e.g. coeliac artery

Eales Disease

Diagnosis: Clinical: Retinal hemorrhages, retinal vasculitis, stroke Fundoscopy/slit lamp exam: Bilateral +Vascular sheathing (thin white lines along either side of the vessel) +Peripheral nonperfusion +Neovascularisation Microaneurysms, retinal hemorrhages, chorioretinal scars, tortuous vessels, Branch retinal vein occlusion Macular oedema Vitreous hemorrhages & debris, Fluorescein angiography: Leakage of dye in areas of vascular sheathing MRI: White matter … Continue reading Eales Disease

Susac’s syndrome

Synonyms: Retinocochleocerebral vasculopathy Diagnosis: Clinical: Encephalopathy (including psychosis), monocular vision loss, hearing loss Headache Branch retinal artery occlusion MRI: T2 hyperintensity in basal ganglia, thalamus, white matter (almost always involving corpus callosum). May involve brainstem & cerebellum T1 +contrast: leptomeningeal enhancement & parenchymal enhancement Ophthalmic fluorescein angiography: Retinal vasculitis: narrowing, occlusion, vessel wall hyperfluorescence, contrast … Continue reading Susac’s syndrome

Alagille syndrome

Synonyms: Arteriohepatic dysplasia Diagnosis: Genetics: Autosomal dominant JAG1 gene Chr. 20p, jagged1 Clinical features and investigations: Syndrome of involvement of Liver: LFTs: cholestasis, Ultrasound, MRCP: intrahepatic bile duct paucity +other systems including: Heart: coarctation of the aorta, aortic aneurysm Eyes: anterior chamber defects, posterior embryotoxon Face: frontal bossing, deep set eyes, bulbos nose tip, pointed … Continue reading Alagille syndrome

Cerebral Autosomal Dominant Arteriopathy and Subacute Infarcts with Leukoencephalopathy

Cerebral autosomal dominant arteriopathy and subacute infarcts with leukoencephalopathy (CADASIL) Diagnosis: Genetic testing: Notch 3 gene mutation on chromosome 19. Clinical including family history plus biopsy (skin or brain) +MRI: Diffuse white matter lesions including frontal lobes, temporal lobes (especially anteriorly), insula, deep & periventricular white matter. T2 hyperintense T1 hypointense Pathology: Skin biopsy: Electron … Continue reading Cerebral Autosomal Dominant Arteriopathy and Subacute Infarcts with Leukoencephalopathy

Postpartum Cerebral Angiopathy

Synonyms: Postpartum cerebral vasculopathy: Diagnosis: There are two forms: Idiopathic postpartum angiopathy a.k.a. Call-Fleming postpartum angiopathy Secondary postpartum cerebral angiopathy: Due to bromocriptine (used for lactation suppression), ergot alkaloids (used for control postpartum hemorrhage), sympathomemimetics, nasal decongestants Clinical features: Headache, seizure, encephalopathy within 1 month of delivery Normotensive (normal BP), no proteinuria MRI: In the … Continue reading Postpartum Cerebral Angiopathy

Cerebral Venous Sinus Thrombosis

Synonyms: Cerebral venous thrombosis CVT or cerebral venous sinus thrombosis/dural sinus thrombosis CVST and also Cortical cerebral venous thrombosis:   Diagnosis: By neuroimaging including CT venography, MR venography or catheter angiography revealing thrombus in the cerebral venous sinuses. May be clinically symptomatic or asymptomatic   Pathology: Any combination of the following may be involved: Venous … Continue reading Cerebral Venous Sinus Thrombosis

Moyamoya disease

Synonyms: Moyamoya disease a.k.a. idiopathic progressive arteriopathy of childhood a.k.a. spontaneous occlusion of circle of Willis: Diagnosis: Moyamoya syndrome is an angipathic pattern, not a specific disease. It has primary & secondary causes Moyamoya disease referes to the idiopathic condition that represents primary moyamoya syndrome   Clinical features: Bimodal age of onset: children ~5 years … Continue reading Moyamoya disease

Posterior Cortical Atrophy

Synonyms: Visual variant of Alzheimer’s disease, Benson’s syndrome   Clinical features: Features of Gerstmann’s syndrome (Alexia, Acalculia, Agraphia, Left-right agnosia/disorientation, Finger agnosia) Features of Balint’s syndrome (simultanagnosia, oculomotor apraxia, optic ataxia), Apperceptive visual agnosia, dressing apraxia, environmental disorientation, hemianopia, transcortical sensory aphasia Less commonly: memory or language disturbances Localises to visual association cortex bilaterally, usually … Continue reading Posterior Cortical Atrophy

Huntington Disease

Genetics: Autosomal dominant HD gene chr. 4p16.3, expansion of CAG trinucleotide repeat. Protein= huntingtin, mutation= expansion of polyglutamine segment. Norma repeat is <26 repeats, Hungtingtons disease if = or >36 repeats Genetic testing for CAG repeat expansion in the huntingin gene Clinical: Chorea, personality change, dementia Chorea: initially as fidgety movements, then it affects fingers, … Continue reading Huntington Disease

Diffuse Lewy Body Disease

Synonyms: Dementia with Lewy bodies, a.k.a. Lewy body dementia a.k.a. Diffuse Lewy body disease DLBD, formerly Lewy body varient of Alzheimers: Clinical features: Dementia: deficits in attention, executive function, visuospatial ability and later on in memory. This is a subcortical dementia i.e. cortical features are spared early in the disease Core features: Dementia that develops … Continue reading Diffuse Lewy Body Disease


This section will not cover all of epilepsy as it is a major subspeciality within neurology. But here is an introduction to get you started. Epilepsy is a clinical diagnosis supported by electoencephalography (EEG) evidence of seizure or certain inter-ictal findings. Epilepsy is a disorder of recurrent unprovoked seizures. Classically, it requires at least 2 … Continue reading Epilepsy

Subarachnoid Hemorrhage

Synonyms: Subarachnoid haemorrhage Diagnosis: Findings on Investigations: Diagnosis is established by neuroimaging (CT or MRI) or by lumbar puncture Non-contrast CT: Demonstrates subarachnoid hemorrhage in the acute phase. May be negative, but is positive in the majority of cases. If CT is negative LP is indicated. Blood in CSF spaces: sulci & cisterns. May also … Continue reading Subarachnoid Hemorrhage

Intracerebral Hemorrhage

This section will discuss intracerebral hemorrhage; the commonest type of hemorrhagic stroke. Hemorrhagic stroke is a broad category of stroke and includes intracerebral hemorrhage and subarachnoid hemorrhage. Together these two conditions represent 13-20% of stroke cases with the rest being due to ischemic stroke. Intracerebral hemorrhage is more common than subarachnoid hemorrhage with the later … Continue reading Intracerebral Hemorrhage

Ischemic Stroke

Ischemic stroke is the commonest form of stroke. It represents infarction of the brain or spinal cord due to interruption of blood supply. There are many causes including embolism of material such as thrombus, cholesterol or rarely other material. Other mechanisms include thrombosis and miscellaneous causes of interruption of blood flow. The symptoms vary depending … Continue reading Ischemic Stroke

Listeria Rhombencephalitis

Synonyms: Listeria brainstem encephalitis, neurolisteriosis, Listeria meningitis if without parenchymal involvement Diagnosis: Positive CSF gram stain & culture: gram positive bacillus, Listeria monocytogenes Or Positive blood culture: growing Listeria monocytogenes Listeria meningitis if without parenchymal involvement Clinical features: Fever +headache, then brainstem signs, then coma & respiratory failure Findings on Investigations: MRI: lesion in brainstem … Continue reading Listeria Rhombencephalitis

Viral Encephalitis

Viral encephalitis is the commonest cause of encephalitis. The general features and causes of encephalitis are described in a separate section. Here we discuss the various viral encephalitides.   HSV Encephalitis: Diagnosis: Clinical findings combined with MRI features and isolation of virus by PCR or pathology Findings on investigations: CT: Low density in: Insular regions, … Continue reading Viral Encephalitis


Encephalitis is the term used to describe an inflammatory process of the substance of the brain. This distinguishes it from meningitis which is an inflammatory process of the coverings of the brain. There are patients who have inflammation of both areas and this is described as meningo-encephalitis. Patients with encephalitis and those with meningitis present … Continue reading Encephalitis

Fungal Meningitis

There are various fungi that may cause meningitis. The manifestations vary by causative organism and host immune status. Some organisms are more common in certain geographical locations. Patients may present acutely with headache and encephalopathy or may have a much more indolent course.     Cryptococcal meningitis: Synonyms: Cryptococcosis (Cryptococcus neoformans) Diagnosis: Clinical findings plus … Continue reading Fungal Meningitis

Tuberculous Meningitis

Synonyms: Mycobacterium tuberculosis meningitis, TB meningitis, tuberculoma, tuberculous meningovasculitis Diagnosis: Clinical features plus confirmatory CSF analysis or TB studies Findings in Investigations: Findings remain after 10 days treatment White cell count: moderately high, Usually <500/microL, (100-300/mm3) Mainly lymphocytes Protein: High, >0.8g/L Glucose: Low ,<2.2 mmol/l Or atypically: Neutrophilia if early, normal protein, normal glucose Eosinophilia … Continue reading Tuberculous Meningitis

Viral Meningitis

Diagnosis: Clinical features plus confirmation by CSF analysis & isolation of the virus or PCR or antibody tests Findings on Investigations: CSF analysis: Early LP may show: Increased neutrophils, Glucose normal Later: White cell counts: moderately high, <1000/mL (usually 25-500/microL) Lymphocytes or monocytes RCC: raised in HSV encephalitis Glucose normal Protein: Usually normal Or slightly … Continue reading Viral Meningitis

Bacterial Meningitis

Diagnosis: Clinical features plus confirmation by CSF analysis Findings in Bacterial meningitis: High opening pressure >180 mmH2O, turbid/purulent appearance White cell count: high, 10-10,000/microL Mainly neutrophils (usually >100), but monocytes are suggestive of Listeria monocytogenes Protein: High, >0.45 g/L (>45 mg/dL) Glucose: low, <0.4 of serum (roughly <1/2 serum), or <2.2 mmol/L (<40 mg/dL) Borrelia … Continue reading Bacterial Meningitis


Clinical features: Patients present with headache and necks stiffness. They typically have a fever, unless they are immunosupressed, and may have a rash. The classic triad in bacterial meningitis is headache, fever and rash. It is a serious life-threatening medical emergency that often results in significant disability. However, the commonest cause of meningits overall is … Continue reading Meningitis

Amyotrophic Lateral Sclerosis

Synonyms: Lou Gehrig disease Clinical features: Features of upper motor neuron (UMN) disease (including increased reflexes in wasted limb) & lower motor neuron (LMN) disease +/-pseudobular palsy +/-cramps Weakness, fasciculations No sensory disturbance, no bowel or bladder dysfunction Diagnostic criteria: El Escorial criteria, also known as, World Federation of Neurology criteria (used more for research) … Continue reading Amyotrophic Lateral Sclerosis

Parkinson's Disease

Synonyms: Paralysis agitans: Clinical features: Triad of: Bradykinesia Rigidity. Tremor: this is not essential for the diagnosis Important characteristics: asymmetry, upper body is affected first, fluctuation in severity, postural instability later on BP & postural BP: to exclude Shy-Dragger syndrome Other clinical points: Re-emergent tremor: on testing for postural tremour, initially there is no tremour … Continue reading Parkinson's Disease

Alzheimer Disease

Clinical features: Clinical features in general: Episodic memory loss: This is usually the first symptom  to develop. It preceeds the dysfunction in activities of daily living. In most cases Alzeimer disease develops from amnestic mild cognitive impairment. Later on other cognitive domains are involved this leads to: Executive dysfunction Agnosia Apraxia Aphasia Neuropsychiatric symptoms: depression, … Continue reading Alzheimer Disease

Multiple Sclerosis

This is an autoimmune disease of the central nervous system white matter. There is some evidence that the grey matter may be involved in the disease, but it is best to think of it as a type of white matter disease. The disease is multifocal i.e. it affects non-adjacent parts of the white matter. The … Continue reading Multiple Sclerosis


  Approaches: Localization by level of lesion: Cervical Thoracic Lumbar (Conus medullaris and cauda equina syndrome) Localization by cross-sectional origin of pathology: Extradural Intradural extramedullary Intramedullary (within the spinal cord) Anatomical syndromes Anterior cord syndrome Central cord syndrome Transverse myelitis Brown-Sequard syndrome   Anatomical syndrome approach: Anterior cord syndrome: Anatomy: lesion at anterior aspects of … Continue reading Myelopathy