Tag Archives: Weakness

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


Clinical features (neurological porphyrias): General features: Acute ascending paralysis with areflexia, affecting VII nerve as well Sensory loss may occur “swimming trunk distribution” Autonomic neuropathy: tachycardia and orthostatic hypotension Confusion, anxiety Urine becomes dark on exposure to sunlight. Subtypes: Acute forms: Cause neurological disease and raised ALA Acute intermittent porphyria AIP: no cutaneous rash Variegate … Continue reading Porphyria

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

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

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

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

Necrotizing Autoimmune Myopathy NAM

Diagnosis: Clinical features plus positive antibodies and usually with necrotizing myopathy on biopsy Clinical features: Age range 30-60, progressive myopathy with profound proximal muscle weakness. May also occur in patients recieving statins, but most patients are statin naive Antibodies: Positive antibodies Anti-HMGCR Abs (3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase) Muscle biopsy: H&E: Necrotic fibers with a few regenerating … Continue reading Necrotizing Autoimmune Myopathy NAM

Lipid Storage diseases

Lipide storage myopathies: Carnitine deficiency Carnitine palmityl transferase II deficiency   Carnitine deficiency: Diagnosis: There are various forms: Muscle carnitine deficiency Systemic carnitine deficiency Secondary carnitine deficiency Muscle carnitine deficiency: Low muscle carnitine levels. Normal systemic carnitine levels Muscle biopsy: Vacuolar myopathy. Lipid droplets in type 1 fibres. Systemic carnitine deficiency: Systemic carnitine levels: low … Continue reading Lipid Storage diseases

Myoadenylate Deaminase Deficiency MAD deficiency

Genetics: Autosomal recessive AMPD1 gene mutation chr. 1 Clinical features: Broad: childhood to late adulthood, myalgia induced by exercise to rhabdomyolysis Skeletal muscle only, non-progressive Muscle biopsy: MAD: no staining Treatment: D-Ribose P.O. Related articles: Myopathy,

Sporadic Late Onset Nemaline Myopathy SLONM

Synonyms: a.k.a. Adult from of nemalin myopathy a.k.a. acquired nemaline myopathy, rare: Clinical features: Adults a.k.a. late onset nemaline myopathy: usually >40 year olds, head drop, proximal >distal weakness, dysphagia, respiratory weakness, proximal and axial atrophy Associated conditions: SPEP: monoclonal gammopathy. HIV associated nemaline myopathy. Muscle biopsy: HE fibre atrophy without grouping, subsarcolemmal increased eosinophilic … Continue reading Sporadic Late Onset Nemaline Myopathy SLONM

Condrodystrophic Myotonia

This is a very rare condition Synonyms: a.k.a. Schwartz-Jampil Syndrome SJS Clinical features: Myotonia +distichiasis (double row of eyelashes) Findings on investigations: EMG: Myotonia Genetics: Autosomal recessive Genetics: Perlecan gene mutation, HSPG2 gene chr. 1p35-p36.1 Related articles: Myopathy, Myotonic dystrophy DM1, Proximal myotonic myopathy (Myotonic dystrophy DM2), Myotonia Congenita (Thomsen’s disease)

Paramyotonia Congenita

Genetics: SCN4A 17q23 Clinical features: Myotonia (inability to relax) No improvement with exercise Precipitated by cold exposure. Flaccid paralysis may occur Related articles: Myopathy, Myotonic dystrophy DM1, Proximal myotonic myopathy (Myotonic dystrophy DM2), Myotonia Congenita (Thomsen’s disease)

Non-Dystrophic Myotonias

Diagnosis: Clinical features: childhood onset of myotonia +muscle hypertrophy There are multiple forms: Becker myotonia: Autosomal recessive Thomsen disease: (see appropriate section) Genetics: Autosomal dominant Genetic analysis: chloride channel CLCN1 gene mutations on chromosome 7. Different mutations for each. Muscle biopsy: Variation in fibre size. Rare centronucleation. Type 2A fibre hypertrophy. Type 2B fibres may … Continue reading Non-Dystrophic Myotonias

Myotonia Congenita

A form of nondystrophic myotonia Synonyms: a.k.a. Thomsen’s disease Clinical features: 1st and 2nd decade When infant: inability to open eyes after face is washed, peculiar cry Muscular hypertrophy (generalized), myotonia (worse in cold), No weakness Warm up phenomenon: improved strength and movement after warm up Genetics: Autosomal dominant Genetic analysis: chloride channel CLCN1 gene mutations on … Continue reading Myotonia Congenita

Proximal Myotonic Myopathy

Synonyms: a.k.a. myotonic dystrophy type 2 a.k.a. DM2 Diagnosis: The diagnosis is confirmed by genetic analysis Muscle biopsy: type 2 fibre atrophy, Genetics: Genetic analysis: CCTG repeat expansion in ZNF9 gene chromosome 3. Related articles: Myopathy, Myotonic dystrophy DM1,

Myotonic Dystrophy DM1

Synonyms: a.k.a. Dystrophia myotonica a.k.a. DM a.k.a. DM1 a.k.a. Steinert disease Diagnosis: Clinical +EMG +consistent labs Clinical features: Early frontal baldness, Wasting of temporalis (hatchet face), massester and sternocleidomastoid (swan neck), Ptosis, facial weakness. Weakness and atrophy of distal arms and finger flexors, and quadriceps and tibialis anterior (foot drop) Decreased reflexes Myotonia: difficulty releasing … Continue reading Myotonic Dystrophy DM1

Congenital Muscular Dystrophies CMD

These are a type of muscular dystrophy. Don’t confuse these diseases with non-dystrophic congenital myopathies. Merosin (Laminin 2) negative CMD: Clinical features: Cause hypotonia in the infant Pathology, Muscle or skin biopsy: H and E: dystrophic picture Immunohistochemistry: absent Mersonin (Laminin 2) in basement membrane. Findings on investigations: MRI: white matter changes   Merosin positive … Continue reading Congenital Muscular Dystrophies CMD

Oculopharyngeal Dystrophy OPMD

Synonyms: a.k.a. oculopharyngeal muscular dystrophy OPMD Muscle biopsy: Rare rimmed vacuoles. Intranuclear inclusions. Occasionally type 1 fibre predominance and occasionally ragged red fibres Genetics: Autosomal dominant PABP2 gene, Chr. 14q11.2-q13, expanded trinucleotide repeat (polyalanine) GCG in PABP2 poly A binding nuclear protein 2. Clinical features: Ptosis, dysphagia Later on proximal limb weakness and gait abnormalities … Continue reading Oculopharyngeal Dystrophy OPMD

Fascioscapulohumeral Myopathy FSH

Synonyms: a.k.a. Landuzy-Dejerine disease Muscle biopsy: 3 patterns Pseudoneurogenic: atrophied angulated fibres in nests Dystrophic: whorled fibres, moth eaten fibres, lobulated fibres. Endomysial fibrosis. Pseudomyositic: inflammatory cellular mononuclear infiltrates Diagnosis: Genetic analysis (blood test): deletion at 4q35. i.e. deletion of the telomeric region Genetics: Genetic analysis (blood test): deletion at 4q35. i.e. deletion of the … Continue reading Fascioscapulohumeral Myopathy FSH

Emery-Dreifuss Muscular Dystrophy

Synonyms: a.k.a. Humeroperoneal dystrophy Genetics: X linked recessive Clinical features: Weakness in biceps, triceps, distal leg muscles Early contractures Rigid spine Findings on investigations: Cardiac conduction block Muscle biopsy: Dystrophic changes similar to Duchenne muscular dystrophy Immunohistochemistry: absent Emerin is diagnostic. Investigations to consider: Monitor cardiac function: conduction abnormalities Treatment: Consider insertion of pacemaker Physical … Continue reading Emery-Dreifuss Muscular Dystrophy

Becker Muscular Dystrophy, BMD

Diagnosis: Must confirm with Western Blotting and genetic testing Quantitative dystrophin analysis by Western blotting: decreased dystrophin Muscle biopsy: Similar findings to Duchenne muscular dystrophy, but less severe. Immunohistochemistry: variation in staining for dystrophin between and within fibres. Use antibodies against different regions of dystrophin to avoid false negatives. Must confirm with Western Blotting and … Continue reading Becker Muscular Dystrophy, BMD

Glycogenoses (glycogen storage diseases)

Pompe disease: Synonyms: a.k.a. type 2 glycogenosis a.k.a. glycogen storage disease type II GSD II a.k.a. acid maltase deficiency, rare: Diagnosis: A type of lysosomal storage disease and a glycogen storage disease. Genetics: GAA gene chr. 17. Protein= alpha glucosidase Autosomal recessive Biochemical assay: Confirms the diagnosis. Enzyme activity: reduced Skin fibroblasts are best Muscle … Continue reading Glycogenoses (glycogen storage diseases)

Congenital Myopathies

These are the non-dystrophic congenital myopathies Nemaline myopathy a.k.a. nemaline rod myopathy: Clinical features: Floppy infant with facial weakness and respiratory insufficiency. Also see adult from a.k.a. sporadic late onset nemaline myopathy Genetics: Heterogeneous, Autosomal dominant, autosomal recessive Mutations in the following Proteins: Alpha-skeletal actin Nebulin Troponin. Muscle biopsy: HE fibre atrophy without grouping, subsarcolemmal … Continue reading Congenital Myopathies

Limb Girdle Muscular Dystrophies LGMDs

Synonyms: formerly pelvifemoral type, Laden-Mobius variant and scapulohumeral type Diagnosis: Autosomal: most are recessive. Must confirm with genetic testing especially for sarcoglycan and dysferlin. Muscle biopsy: Similar to Duchenne muscular dystrophy Cytoplasmic changes may occur: split fibres, whorls, moth eaten fibres, lobulated fibres Hints to subtypes: GMT, Rimmed vacuoles= Telethoninopathy LGMD2G GMT, Rod-like structures= myotilinopathy … Continue reading Limb Girdle Muscular Dystrophies LGMDs

Duchenne Muscular Dystrophy, DMD

Diagnosis: Genetic testing confirms the diagnosis, as does muscle biopsy Muscle biopsy: Early: variation in fibre size, atrophic fibres, round hypertrophied fibres, centronucleation, regenerating fibres, split fibres. Endomysial connective tissue begins to appear. Later: infiltration by adipose tissue. Poor differentiation of fibre type on ATPase reactions. Inflammatory infiltrates may occur. Immunohistochemistry: total absence of dystrophin … Continue reading Duchenne Muscular Dystrophy, DMD

Malignant Hyperthermia Syndrome

Genetics: Autosomal dominant Ca++ ryanodine receptor 1 RYR1. Ca++ CACN1A3 muscle DPH sensitive Ca++ channel Clinical features: Hyperthermia Rigidity, tachycardia, hypertension, fever, rising CO2, lactic acidosis, rhabdomyolysis Triggered by anesthetic administration e.g. halothane. Also suxamethonium Findings on investigations: Rhabdomyolysis Muscle biopsy: Normal or Non-specific changes Or pre-existing underlying myopathy: central core disease. Some forms of … Continue reading Malignant Hyperthermia Syndrome

Hyperkalemic Periodic Paralysis

Synonyms: formerly Gamstorps disease, adynamia episodica hereditaria Genetics: SCN4A 17q23, M1592V. Cold induced weakness I693T Autosomal dominant Mutations in sodium channel alfa subunit SCN4A Clinical features: Recurrent attacks of weakness. All limbs, spares, respiratory and ocular Weakness after exercise. Myotonia may occur e.g. cold induced Precipitated by K+. Alleviated by Ca++. Improves with age Findings … Continue reading Hyperkalemic Periodic Paralysis

Hypokalemic Periodic Paralysis

Genetics: Autosomal dominant, reduced penetrance in females Ca++ CACN1A3 muscle DPH sensitive Ca++ channel. CACNL1A3 (CACNA1S) gene chr. 1q32 protein= calcium channel L type 1S subunit, Na+ SCNA4A 17q23-q25.3. Or sodium channel alfa subunit SCN4A gene chr. 17q25 Or potassium channel KCNE3 gene chr. 11q13 Clinical features: Commonest form. Recurrent attacks of flaccid weakness. Attacks … Continue reading Hypokalemic Periodic Paralysis

Dyskalemic Myopathy

Diagnosis: Hyper- or Hypo-kalemia causing a myopathy Findings on investigations: +CK markedly raised Muscle Biopsy: swelling, vacuolation. If severe, necrosis. Related articles: Myopathy, Hypokalemic periodic paralysis, hyperkalemic periodic paralysis,

Statin Myopathy

Diagnosis: Clinical features consistent with statin myopathy, exclusion of other causes and improvement of myopathy on discontinuation of statin. Antibody tests can be useful in distinguishig between statin induced necrotizing myopathy and necrotizing autoimmune myopathy. Clinical features: Proximal symmetric muscle weakness, usually spares the face, bulbar muscles and sphincters CK: usually elevated, may be normal … Continue reading Statin Myopathy

Drug Induced Myopathies

Corticosteroid myopathy: See under corticosteroid myopathy Statin myopathy: See under statin myopathy Ziduvodine Mitochondrial myopathy: +Muscle biopsy: Ragged red fibres. COX negative fibres, Pleomorphic mitochondria Distinguishes it from HIV associated inflammatory myopathy Choroquine neuromyopathy +Muscle biopsy: Vacuolar myopathy, especially in type 1 fibres. PAS positive. Electron microscopy: muscle and nerve. Membranous whorlings, myelin figures, curvilinear … Continue reading Drug Induced Myopathies

Critical Care Myopathy

Synonyms: a.k.a. acute quadriplegic myopathy Diagnosis: This is a clinical diagnosis supported by exclusion of other causes. Usually it does not require biopsy but often it is used in cases of uncertainty Clinical features: All limbs, diaphragmatic and intercostal weakness, Occurs in severe illness +/-sepsis, +/-steroids, +/-neuromuscular blocking agents Findings on investigations: +CK normal or … Continue reading Critical Care Myopathy

Corticosteroid Myopathy

Synonyms: Steroid induce myopathy Diagnosis: This is a clinical diagnosis supported by exclusion of other causes. Usually it does not require biopsy but often it is used in cases of uncertainty Clinical features: Proximal weakness, usually gradual onset Findings on investigations: +/-CK normal or reduced +/-Muscle biopsy: Type 2 fibre atrophy, especially type 2B. Lipid … Continue reading Corticosteroid Myopathy

Eosinophilic Myositis and Eosinophilic Fasciitis

Eosinophilic myositis Occurs in hypereosinophilic syndrome, parasitic infections, Churg Strauss syndrome, Muscle biopsy: Inflammatory cells including eosinophils   Eosinophilic fasciitis a.k.a. Shulman syndrome: Clinical features: Subcutaneous induration sparing the face and fingers Stiff joints FBC: raised eosinophils Biopsy: Scleroinflammatory lesions in the fascia, may extend into the dermis or muscle. Well circumscribed or absent eosinophilia … Continue reading Eosinophilic Myositis and Eosinophilic Fasciitis

Macrophagic Myofasciitis MMF

Diagnosis: This is pathological diagnosis Muscle biopsy: Perimuscular infiltrate of large macrophages with PAS positive granular cytoplasm (slightly basophilic on H and E stain). Lymphocytic infiltrate. Usually in deltoid Related articles: Myopathy,

Nodular Focal Myositis

Diagnosis: The diagnosis is confirmed by muscle biopsy Seen in rheumatoid arthritis and other connective tissue diseases Muscle biopsy: Interstitial lymphocyte and plasma cell infiltration forming nodules 1 to 2mm diameter near arteries or arterioles. No invasion of the vessels. Related articles: Myopathy,

Inclusion Body Myositis

Synonyms: a.k.a. inclusion body myopathy IBM Diagnosis: Clinical +Muscle biopsy +neurophysiology Clinical features: Usually >50 year old patients Progressive weakness of quadriceps, ankle dorsiflexors, finger flexors and facial muscles. Dysphagia is common. Pathology, Muscle biopsy Inflammation HE: Rimmed vacuoles: Basophilic granules around vacuoles. Endomysial and perivascular lymphocytes. Increased connective tissue GMT: rimmed vacuoles (red rim), … Continue reading Inclusion Body Myositis

Parasitic Myositis

Trichinosis, Trichinella spiralis: Diagnosis: Muscle biopsy: encysted larvae. Treatment: Thiabendazole Toxoplasma   Related articles: Myopathy,

Bacterial Myositis

Pyomyositis and Tropical pyomyositis: Features: Very debilitated patients in ICU or tropical form Acute, spontaneous i.e. non-traumatic suppurative infection, abscess formation Gas gangrene, Clostridium perfringens Diagnosis: Traumatic or surgical. Also spontaneous gas gangrene Clostridium septicum in colon cancer patients. Gram stain of bullae fluid: gram positive rods Tissue biopsy may be necesary to confirm the … Continue reading Bacterial Myositis

Viral Myositis

Acute viral myositis: Viral causes: Influenza virus: Acute benign myositis or rhabdomyolysis. Coxsackie B virus: Bornholm disease or epidemic myalgia AIDS myopathy: HIV associated myopathy: Similar to seronegative polymyositis Muscle biopsy: HIV antigens in the endomysial and perivascular macrophages are usually present Muscle fibres express MHC-1 molecules Primary muscle lymphoma can occur in AIDS patients … Continue reading Viral Myositis


Diagnosis: Urinalysis for myoglobin Investigations to consider: CK Basic metabolic panel Monitor: K+ and renal function Treatment: Hydration to increase urine volume Treat hyperkalemia Treat the cause Treat renal failure Related articles: Myopathy, rhabdomyolysis,


Diagnosis: This is a clinical diagnosis supported by laboratory tests Findings on investigations: +CK markedly raised +/-EMG Florid myopathic motor unit pattern. Spontaneous potentials in many muscles Muscle biopsy, if done: Necrosis of a large number of fibres Other tests: Urinalysis: hematuria on dipstick which is actually myoglobinuria BASIC METABOLIC PANEL: hyperkalemia, hypocalcemia, hyperphosphatemia, hyperuricemia … Continue reading Rhabdomyolysis

Denervation Atrophy

Diagnosis: Muscle biopsy: Fibre size variation with angulated fibres (rounded fibres in spinal muscular atrophy) Grouped atrophy, bags of nuclei Target fibres Pseudomyopathic pattern Fibre distribution (ATPases): fibre type grouping, grouped atrophy of type 2 and type 1 fibres NADH: target fibres, central clearing Related articles: Nerve diseases, neuromuscular disease patterns, radiculopathy, polyradiculopathy, plexopathy (brachial … Continue reading Denervation Atrophy

Chronic Idiopathic Axonal Polyneuropathy CIAP

Diagnosis: Diagnosis by exclusion. Clinical features: Chronic, sensory or sensorimotor polyneuropathy Findings on investigations: NCS/EMG: Axonal polyneuropathy No evidence of demyelination Related articles: Approach to weakness, approach to sensory deficits, neuromuscular disease patterns, polyneuropathy,

Sjogren Syndrome Neuropathy

Diagnosis: Clinical features of neuropathy plus diagnosis of Sjogren syndrome (by serology or biopsy) plus exclusion of other causes. Vasculitis may occur. Clinical features: Features of neuropathy: small fibre neuropathy, or sensory axonal polyneuropathy, facial palsy CN VII may occur, Findings on Investigations: NCS/EMG: Features of the underlying pattern: small fibre sensory neuropathy, or sensory … Continue reading Sjogren Syndrome Neuropathy

Coeliac Disease Neuropathy

Synonyms: a.k.a. gluten neuropathy Diagnosis: Diagnosis of Coeliac disease or serology positive for coeliac disease, plus clinical or electrodiagnostic neuropathy and exclusion of other causes Clinical features: Different patterns: sensorimotor neuropathy >mononeuropathy multiplex >motor neuropathy >small fibre neuropathy. Findings on investigations: +NCS/EMG: Axonal neuropathy pattern, different patterns (sensorimotor neuropathy >mononeuropathy multiplex >motor neuropathy >small fibre … Continue reading Coeliac Disease Neuropathy

Idiopathic Sensory Perineuritis

Diagnosis: Clinical features of polyneuropathy, mononeuropathy multiplex, biopsy findings of perineuritis and exclusion of secondary causes Clinical features: sensory patchy neuropathy, sensorimotor forms exist. Pathology, nerve biopsy: Perineurium: inflammatory lymphocytic infiltrate, thickening of perineurium Exclusion of other causes Treatment: Consider corticosteroids Related articles: Approach to weakness, approach to sensory deficits, neuromuscular disease patterns, polyneuropathy, Diabetic … Continue reading Idiopathic Sensory Perineuritis

HIV Neuropathy

Synonyms: a.k.a. HIV associated polyneuropathy: Diagnosis: HIV infection with clinical features of neuropathy (many forms) with exclusion of other causese Many forms: CIDP, GBS, mononeuritis multiplex, sensory ataxic neuropathy, lumbosacral plexopathy, polyneuropathy Clinical features: Depends on the underlying subtype (see above) Findings on investigations: NCS/EMG, same as respective idiopathic forms Note: Guillain-Barre Syndrome occurs at … Continue reading HIV Neuropathy

Heavy Metal Neuropathy and Solvent Neuropathy

Diagnosis: Neuropathy +documented high heavy metal level +improvement of symptoms/signs/NCS/EMG after withdrawal of agent Clinical features: Clinical features of neuropathy: may be motor neuropathy, sensori-motor polyneuropathy Findings on investigations: NCS/EMG: Axonal pattern Specific causes: Lead neuropathy (see lead poisoning), Mercury (see mercury poisoning), Others, arsenic, thallium, gold, N-Hexane inhalation Related articles: Approach to weakness, approach … Continue reading Heavy Metal Neuropathy and Solvent Neuropathy

Alcohol Neuropathy

It is unclear if alcoholism without associated nutritional deficiency can cause neuropathy Clinical features: Painful sensory polyneuropathy. Pain on light touch a.k.a. allodynia. Loss of ankle jerks Improvement with withdrawal of alcohol and B1 supplementation Related articles: Approach to weakness, approach to sensory deficits, neuromuscular disease patterns, polyneuropathy, Nutritional neuropathy,

Chronic Renal Failure Neuropathy

Synonyms: a.k.a. uremic neuropathy Diagnosis: Clinical or electrodiagnostic features of neuropathy plus chronic renal failure and exclusion of other cause Clinical features: Distal sensorimotor neuropathy +chronic renal failure +resolves with dialysis or treatment of chronic renal failure Findings on investigations: EMG/NCS: Distal Sensorimotor neuropathy In some cases carpel tunnel syndrome Pathology/Nerve biopsy: Axonal loss Related … Continue reading Chronic Renal Failure Neuropathy

Hypophosphatemia Neuropathy

Diagnosis: Clinical features of neuropathy plus phosphate deficiency and exclusion of other causes Clinical features: Acute, Sensorimotor, areflexia, dysarthria Phostphate levels: <2.4 mg/dl Findings on investigations: NCS/EMG: Demyelinating pattern (Prolonged distal latencies, reduced conduction velocities) [case report] In some cases axonal pattern [case reports] F-waves absent Decreased recruitment (neurogenic recruitment) Pathology/Nerve biopsy: Sub-perineural edema, mild … Continue reading Hypophosphatemia Neuropathy

Nutritional Deficiency Neuropathy

Synonyms: a.k.a. nutritional neuropathy Diagnosis: The diagnosis is based on clinical features of neuropathy supported by electrodiagosis and confirmation of nutritional deficiency with exclusion of other causes +improvement of symptoms/signs/NCS/EMG after supplementation Clinical features: Usually features of polyneuropathy. Most commonly sensori-motor neuropathy +documented deficiency Findings on investigations: NCS/EMG: Usually Axonal pattern Pathology, nerve biopsy: Perineuritis … Continue reading Nutritional Deficiency Neuropathy

Charcot-Marie-Tooth disease CMT

Synonyms: Hereditary Motor and Sensory Neuropathy HMSN Now the whole group is called Charcot-Marie-Tooth disease CMT Diagnosis: Clinical +electrodiagnostics (EMG/NCS) +Genetic testing: Clinical features: Abnormal LMN features: weakness Atrophy: champagne-glass legs, stork legs Deformity: claw toe, Friedreich’s foot, kyphoscoliosis Sensory features: loss of vibration and later on loss of proprioception Palpable nerves Genetics: CMT1 a.k.a. … Continue reading Charcot-Marie-Tooth disease CMT

Acromegaly Neuropathy

Diagnosis: Clinical features of neuropathy plus diagnosis of acromegaly and exclusion of other causes Clinical features: Carpal tunnel syndrome, tarsal tunnel syndrome Polyneuropathy Findings on investigations: NCS/EMG: Carpal tunnel syndrome, tarsal tunnel syndrome Polyneuropathy Pathology, Nerve biopsy: Initially: demyelination Onion bulb formation in end stage Related articles: Approach to weakness, neuromuscular disease patterns, polyneuropathy,

Cranial Neuropathies

Here are some lists to help with the cranial neuropathies. Please see the underlying sections. Also see the section on vertigo for cranial nerve VIII diseases. Synonyms: Cranial neuropathy Causes of Oculomotor nerve palsy (CN III): think of anatomy Nuclear & fasciular: Tumours: Glioma Part of a brainstem stroke syndrome Basilar area: Meningitis: Bacterial, Meningovascular … Continue reading Cranial Neuropathies

Diabetic Neuropathy

There are various types of diabetic neuropathy Diabetic polyneuropathy (sensory type and sensorimotor type): Diagnosis: Features of polyneuropathy and meeting criteria for diabetes mellitus Clinical features: Symmetric sensory polyneuropathy, loss of vibration, pain, touch and temperature sensation and in some cases proprioception loss and Charcot joints Areflexia Painful May become sensorimotor Pathology, nerve biopsy: Nonspecific … Continue reading Diabetic Neuropathy

Paraneoplastic Vasculitic Neuropathy PVN

Synonyms: or paraneoplastic neuromyopathy Diagnosis: A subtype of nonsystemic vasculitic neuropathy, requires features of neuropathy on clinical exam or electrodiagnostic studies plus evidence of vasculitis and underlying neoplastic disorder Clinical features: Weakness +/-sensory abnornalities, often with features of mononeuropathy multiplex Findings on investigations: +Nerve conduction studies +EMG: Polyneuropathy or mononeuritis multiplex, axonal neuropathy +/-evidence of … Continue reading Paraneoplastic Vasculitic Neuropathy PVN

Nonsystemic vasculitic neuropathy NSVN

Diagnosis: This is based on clinical features +nerve/muscle biopsy findings of vasculitis +exclusion of systemic causes Clinical features: Clinical features: usually subacute, painful, distal, asymmetric, Findings on investigations: +Nerve conduction studies +EMG: Axonal neuropathy +CSF analysis: increased protein +ESR: might be increased +ANCA negative Pathology, nerve biopsy: Sural nerve or superficial peroneal nerve biopsy +/-muscle … Continue reading Nonsystemic vasculitic neuropathy NSVN

Systemic Vasculitic Neuropathy

Diagnosis: The diagnosis is made based on clinical features +Peripheral neuropathy, +evidence of vasculitis, +evidence of other organ involvement Clinical features: acute, mononuritis multiplex or less commonly mononeuritis simplex or symetric polyneuropathy, sensorimotor +Peripheral neuropathy +evidence of vasculitis +evidence of other organ involvement Findings on investigations: +NCS/EMG: NCS: Axonal neuropathy Conduction block: often transient CMAP: … Continue reading Systemic Vasculitic Neuropathy

Anti-sulfatide Neuropathy

Synonyms: a.k.a. anti-chondroitin sulfate neuropathy: Diagnosis: The diagnosis is made based on clinical features supported by electrodiagnostic tests and antibodies Clinical features: Polyneuropathy (sensory, or sensorimotor, sensory>motor), ataxia may occur, Findings on investigations: Anti-sulfatide antibody (a.k.a. anti-chondroitin sulfate): positive, > 1:1000 titre SPEP +IFE: usually have monoclonal IgM NCS/EMG: Mainly demyelinating pattern with secondary axonal … Continue reading Anti-sulfatide Neuropathy

Anti-GALOP syndrome: Gait ataxia, autoantibody, late onset polyneuropathy

Synonyms: a.k.a. gait ataxia and polyneuropathy GAPN Diagnosis: Clinical features: Late onset 70 year olds, gait ataxia (wide based with falls) and polyneuropathy (sensorimotor, sensory>motor, impaired proprioception) Anti-GALOP (IgM against central myelin antigen a.k.a. galopin): positive, SPEP +IFE: monoclonal IgM Treatment: Intravenous immunoglobulin IVIG cyclophosphamide Related articles: Approach to weakness, neuromuscular disease patterns, polyneuropathy, Polyneuropathy … Continue reading Anti-GALOP syndrome: Gait ataxia, autoantibody, late onset polyneuropathy

Lymphoma Associated Neuropathy

Diagnosis: Clinical and electrodiagnostic features supported by isolation of lymphoma Clinical features: Sensorimotor neuropathy, polyradiculopathy in carcinomatous meningitis Findings on investigations: CSF analysis: cytology and flow cytometery in carcinomatous meningitis NCS/EMG: Sensorimotor neuropathy Or polyradiculopathy in carcinomatous meningitis Pathology revealing lymphoma: Cytology, flow cytometery Bone marrow biopsy Lymphnode excitional biopsy Pathology, Nerve biopsy: Axonal neuropathy … Continue reading Lymphoma Associated Neuropathy

Anti-MAG syndrome

Diagnosis: This is diagnosed by a combination of clinical features, NCS/EMG and antibodies Clinical features: Distal symmetric, sensorimotor (sensory> motor), Findings on investigations: Anti-MAG: positive, IgM against myelin associated glycoprotein MAG SPEP +IFE: IgM paraprotein, monoclonal NCS/EMG: Distal slowing Pathology/nerve biopsy: Demyelination, axonal degeneration IgM deposits at sites of MAG localisation Immunohistochemsitry: Immunofluorescence with Anti-immunoglobulin … Continue reading Anti-MAG syndrome

POEMS syndrome: Polyneuropathy Organomegally Endocrinopathy M protein and Skin changes

Diagnosis: A paraneoplastic syndrome to osteoclastic plasmacytoma Pathology: Muscle actin stain; increased vessels in nerves VEGF: elevated serum levels Criteria/Features: Polyneuropathy: Demyelinating sensorimotor polyneuropathy (motor>sensory), usually painless, length dependent Monoclonal gammopathy: Serum protein electrophoresis with immunofixation IFE: M protein, Lambda light chain, immunofixation is necessary to avoid false negatives Osteoclastic plasmacytoma i.e. note lytic Skin … Continue reading POEMS syndrome: Polyneuropathy Organomegally Endocrinopathy M protein and Skin changes

Polyeuropathy Associated with Paraproteinemia

Diagnosis: This is a category of different neuropathies. Neuropathy due to a gammopathy includes anti-MAG syndrome, POEMS, cryoglobulinemia, IgM MGUS polyneuropathy, Anti-GALOP (IgM against central myelin antigen): Gait Disorder, Autoantibody Late-age Onset Polyneuropathy Evidence of paraproteinemia e.g. SPEP: paraproteinemia Pathology, nerve biopsy: Light microscopy: Nonspecific, loss of myelin and/or axons No inflammation except in cryoglobulinemia … Continue reading Polyeuropathy Associated with Paraproteinemia

Multifocal Acquired Demyelinating Sensory And Motor neuropathy MADSAM

Synonyms: Lewis Sumner syndrome LSS Diagnosis: Clinical features supported by +NCS/EMG Clinical features: Chronic, asymmetric, distal, sensorimotor, arms >legs, can affect cranial nerves Findings on investigations: NCS/EMG: Multifocal conduction block in affected nerves, Widespread sensory abnormalities: helps distinguish from MMN, Asymmetric, helps distinguish it from CIDP Serum anti-GM1 antibody: negative, helps distinguish from MMN CSF: … Continue reading Multifocal Acquired Demyelinating Sensory And Motor neuropathy MADSAM

Subacute Inflammatory Demyelinating Polyneuropathy

Synonyms: a.k.a. subacute IDP Diagnosis: Clinical +NCS/EMG Similar to Guillain Barre Syndrome GBS and Chronic inflammatory demyelinating polyradiculopathy CIDP but lasting 4-8 weeks. Related articles: Approach to weakness, neuromuscular disease patterns, polyradiculopathy, Guillain Barre syndrome GBS, Chronic inflammatory demyelinating polyradiculopathy CIDP,

Radiation Induced Radiculopathy

Synonyms: Formerly radiation induced lower motor neuron syndrome: Diagnosis: Clinical exposure to radiation in lower spinal cord and weakness +/-minor sensory involvement MRI +GAD: enhancement of nerve roots Related articles: Polyradiculopathy,

Critical Care Neuropathy CIP

Synonyms: a.k.a. critical illness polyneuropathy CIP Diagnosis: This is a clinical diagnosis supported by electrodiagnostic features Clinical features: Severely ill patient >1 week in ICU, acute weakness (distal initially), areflexia, flaccid tetraparesis, atrophy, difficulty weaning from ventilator, Findings on investigations: +NCS/EMG: EMG/NCS: reduced CMAP amplitude, reduced SNAP amplitude, normal velocities, no conduction block, fibrillations. NCS: … Continue reading Critical Care Neuropathy CIP

Idiopathic Lumbosacral Plexitis

Synonyms: Idiopathic Lumbosacral plexitis a.k.a. lumbosacral plexitis a.k.a. idiopathic neuralgic amyotrophy a.k.a. Lumbosacral plexopathy Diagnosis: The diagnosis is based on clinical features, electrophysiological findings and exclusion of competing causes. Clinical features: Lumbosacral distribution of pain followed by weakness See lumbosacral plexopathy Findings on investigations: +EMG Localises the lesion to the lumbar/sacral plexus Localises the lesion … Continue reading Idiopathic Lumbosacral Plexitis

Radiation Induced Plexopathies (Radiation Plexopathy)

Diagnosis: The diagnosis is made based on findings of plexopathy clinically and on imaging supported by exclusion of other causes. Clinical features: Exposure to radiation, exclusion of other causes Weakness, usually painless Clinical fasciculations and myokymia may occur Findings on investigations: NCS/EMG: Fasciculations and myokymia may occur SNAP and CMAP: slowed conduction velocity is common … Continue reading Radiation Induced Plexopathies (Radiation Plexopathy)

Heredofamilial Brachial Plexopathy

Synonyms: a.k.a. hereditary brachial plexus neuropathy a.k.a. hereditary neuralgic amyotrophy HNA, rare: Clinical features: Usually Painless Attacks of weakness with recovery over weeks +some cranial involvement Genetics: Mapped to chr. 17q24-25 Autosomal dominant Findings on investigations: NCS/EMG: may be normal between attacks Pathology, nerve biopsy: Semithin plastic sections: Tomacula (sausage like excess myelin) Teased fibres: … Continue reading Heredofamilial Brachial Plexopathy

Carcinomatous Plexopathy

Diagnosis: The diagnosis is confirmed by isolation of the causative neoplasm and electrophysiological and clinical findings Clinical features: Painful, Features of brachial plexopathy or those of lumbosacral plexopathy: Weakness in lower plexus C8, T1 distribution +atrophy Associated with Horner’s syndrome Asymmetric leg weakness, reduced reflexes Findings on investigations: NCS/EMG: Denervation (fibrillations and positive sharp waves … Continue reading Carcinomatous Plexopathy

Acute Brachial Plexus Neuritis

Synonyms: a.k.a. Parsonage-Turner syndrome formerly brachial neuralgic amyotrophy Diagnosis: This is a clinical diagnosis supported by electrophysiological findings and consistent imaging Clinical features: Brachial distribution of pain followed in 3-10 days by weakness and atrophy with areflexia In some cases sensory loss may occur May be bilateral Findings on investigations: +EMG: Localised to brachial plexus, … Continue reading Acute Brachial Plexus Neuritis

Neurogenic Thoracic Outlet Syndrome

This is a type of cervical rib syndrome. There is a related vascular thoracic outlet syndrome. Diagnosis: The diagnosis is made by clinical and electrophysiological (NCS/EMG) and then imaging to identify the underlying case. Clinical features: Pain: C8 andT1 Sensory loss C8 and T1 Weakness: abductor pollicis brevis Puling on the arm (down) reproduces sensory … Continue reading Neurogenic Thoracic Outlet Syndrome


Diagnosis: This is a clinical diagnosis supported by electrophysiological findings on NCS/EMG Clinical features of radiculopathy in general: Motor or sensory involvement restricted to the distribution of an isolated nerve root level e.g. C5 nerve rooth or L5 nerve root. The motor involvement may include weakness, atrophy or rarely faciculations in a myotome distribution. The … Continue reading Radiculopathy


Synonyms: Polyradiculoneuropathy Diagnosis: The diagnosis is clinical supported by electrophysiological studies (NCS/EMG) Clinical features: A syndrome with involvement of multiple nerve roots and peripheral nerves. Usually equal proximal and distal weakness with reduced reflexes Findings on investigations: +NCS: Symmetrical i.e. <50% difference between sides Decreased SNAP Decreased CMAP Motor conduction velocities: mild decrease (remaining >75% … Continue reading Polyradiculopathy

Brachial Plexopathy

Diagnosis: The diagnosis is made based on clinical features supported by neurophysiology (NCS/EMG) Findings on investigations: Neurophysiology (NCS/EMG) SNAP: More sensitive than CMAP Normal conduction velocity and distal latency Decreased amplitude in affected nerve (may be normal initially). CMAP: Indicates severe injury Decreased amplitude Conduction block distal to Erb’s point (i.e. amplitude is reduced at … Continue reading Brachial Plexopathy

Congenital Myasthenic Syndromes

Classification: Presynaptic: Choline Acetyltransferase Synaptic: Endplate acetylcholinesterase AChE deficiency Postsynaptic: AChR deficiencies AChR kinetic abnormalities (slow & fast channel syndromes) Rapsyn mutation Diagnosis: In general: AChR antibodies: negative Genetic testing confirms the diagnosis Clinical features: At birth or <2 y.o.: Respiratory and feeding difficulties Ocular symptoms (ptosis impaired movements) NCS/EMG: RNST: decrement in amplitude CMAP … Continue reading Congenital Myasthenic Syndromes

Neonatal Myasthenia

Diagnosis: Myasthenia in a new born to a mother with myasthenia gravis AChR antibodies: positive Clinical features: Weakness, hypotonia, dysphagia, weak cry and suck, Edraphonium/Tensilon test positive Mother with myasthenia gravis Treatment: Neostigmine Rarely plasma exchange Related articles: Approach to weakness, neuromuscular disease patterns, neuromuscular junction disorders,

Clostridium tetani (tetanus)

Diagnosis: This is a clinical diagnosis supported by electrophysiological features Clinical features: Tetany: lockjaw (trismus), wrinkled forehead (frontalis), closed eyes (orbicularis oculi), retracted lips (resus sardonicus), contracted bulbar muscles, neck, limbs, rigidity, board-like abdomen Spasms: opsotonos, paroxysms of contraction, pharyngeal/laryngeal spasms, Diaphoresis, BP swings Localised tetany: rigidity and spasms localised to one part of the … Continue reading Clostridium tetani (tetanus)

Clostridium botulinum neurotoxin (Botulism)

Diagnosis: The diagnosis is by clinical features supported by neurophysiology and confirmed by toxin testing Clinical features: Types: Wound botulism, infant botulism, food botulism, Descending weakness (ocular opthalmoplegia then pharyngeal then limbs) Loss of pupil accommodation, constipation, ileus Reflexes reduced or absent Normal sensation Findings on investigations: NCS/EMG: RNST at 20 and 50 Hz: incremental … Continue reading Clostridium botulinum neurotoxin (Botulism)

Lambert Eaton Myasthenic Syndrome LEMS

Synonyms: LEMS a.k.a. Myasthenic syndrome Diagnosis: The diagnosis is made by a combination of clinical features, autoantibodies and electrophysiology Clinical features: Proximal weakness (shoulder and pelvic) and neck muscle weakness Improve with exercise, sometimes this is not clinically detectable Reduced or absent reflexes Cholinergic autonomic failure (dry mouth, constipation, impotence, decreased sweating, blurred vision) Findings … Continue reading Lambert Eaton Myasthenic Syndrome LEMS

Mononeuropathy Multiplex

Synonyms: Mononeuropathy multiplex a.k.a. mononeuritis multiplex Diagnosis: This is a clinical plus electrophysiological diagnosis Clinical features: a syndrome with involvement of at least two separate nerves. Usually sensorimotor. Findings on investigations: +NCS: Axonal, asymmetrical i.e. >50% difference between sides, distribution of multiple separate nerves Decreased SNAP Decreased CMAP Motor conduction velocities: mild decrease (remaining >75% … Continue reading Mononeuropathy Multiplex


Synonyms: Distal symmetric polyneuropathy Diagnosis: This is a clinical diagnosis supported by electrophysiologic (nerve conduction studies and electromyography) testing. The underlying cause may be determined based on blood tests and other testing. Clinical features: Subtypes: sensory, senosrimotor, autonomic or combination. It may be axonal or demyelinating. Axonal forms are more common. Typical features: Distal symmtric … Continue reading Polyneuropathy

Electrical injury to anterior horn cells

Diagnosis: This is usually a clinical diagnosis based on exposure to electrical injury and clinical features of lower motor neuron disease Clinical features LMN disease (weakness, with reduced or absent reflexes), minimally progressive Previous electrical injury Related articles: Approach to weakness, Neuromuscular disease patterns, Amyotrophic lateral sclerosis,


Synonyms: Mononeuropathy, including Compressive neuropathy a.k.a. nerve compression Diagnosis: This is a clinical diagnosis supported by electrophysiology (NCS/EMG) Clinical features: Dysfunction limited to one isolated peripheral nerve for example the median nerve, the ulnar nerve, the radial nerve, the femoral nerve, the peroneal nerve etc. Only one nerve involved. This distinguishes the syndrome from mononeuropathy … Continue reading Mononeuropathy

Spinal and bulbar muscular atrophy, Kennedy disease

Synonyms: Spinal and bulbar muscular atrophy (SBMA), Kennedy disease Diagnosis: This is a clinical diagnosis supported by NCS/EMG Clinical features: Lower motor neuron (LMN) disease Muscle atrophy, weakness, contraction fasciculations, and bulbar involvement Gynecomastia, testicular failure Genetics: Androgen receptor (AR) gene, expansion of CAG trinucleotide repeat Related articles: Approache to weakness, nerve diseases, Amyotrophic lateral … Continue reading Spinal and bulbar muscular atrophy, Kennedy disease

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: A combination of clinical features and CSF analysis Clinical features: Prodrome: upper respiratory tract infection Followed by: Mild meningismus +headache Myalgial, paraesthesia, paralysis and respiratory weakness After recovery LMN features and flaccid weakness. Autonomic features (swollen, clammy, cold, purple) in Lower limbs. Findings in Investigations: CSF: Pleocytosis Serology NCS/EMG: Asymmetrical involvement. Motor evoked potential … Continue reading Poliomyelitis

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

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:

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,

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)

Bell's Palsy

Synonyms: Idiopathic facial nerve palsy (CN VII) Diangosis: Bell’s palsy is a diagnosis by exclusion Clinical diagnosis: Unilateral Lower motor neuron pattern facial palsy (the forehead muscles are involved) Bell’s phenomenon: the eyes will roll upwards and backwards when eyelid closure is attempted. This is a normal response that occurs in everyone, but it is … Continue reading Bell's Palsy

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

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


Clinical features: Proximal muscle weakness; may be asymmetric. Muscle wasting is late Shoulder girdle tenderness (may be absent) Dysphagia & neck muscle weakness may occur Spares face muscles & ocular muscles Muscle biopsy: Endomysial (within the fascicles): muscle fibre necrosis, lymphocytes (absence of eosinophils & plasma cells). Absence of rimmed vacuoles. Surrounding healthy fibres. If … Continue reading Polymyositis


 Clinical features: Heliotrope ‘lilac/purple blue’ rash around the eyelids, malar region, extensors, knuckles, trunk Gottron’s papules on hand dorsum Nailfold telangiectasia & erythema Nail changes; thickening, cracking Proximal Muscle weakness Findings on investigations: Nerve conduction studies/electromyography NCS/EMG: MUAP Myopathic recruitment On activation: Short duration, low amplitude polyphasic units Spontaneously: increased activity with fibrillations, complex repetitive … Continue reading Dermatomyositis

Chronic Inflammatory Demyelinating Polyradiculopathy

Synonyms: Chronic inflammatory demyelinating polyradiculoneuropathy a.k.a. Chronic inflammatory demyelinating polyneuropathy, CIDP Diagnosis: Is by clinical findings supported by +NCS/EMG and occasionally nerve biopsy Clinical features: Clinical: >2 months, gradual onset, usually sensorimotor, arms & legs, proximal weakness & distal weakness, usually spares the cranial nerves, thickened nerves may occur. NCS/EMG Nerve conduction studies: Key features: … Continue reading Chronic Inflammatory Demyelinating Polyradiculopathy

Lumbosacral Plexopathy

Diagnosis: This is a clinical diagnosis supported by neurophysiological (electrophysiology NCS/EMG) tests Clinical features: Weakness and sensory loss in lumbosacral distribution that spares the paraspinal muscles and is usually asymmetric in a distribution localizing to the plexus. Lumbar plexopathy: Loss of knee reflex Weakness: hip flexors, hip adductors, knee extensors, Reverse straight leg sign may … Continue reading Lumbosacral Plexopathy

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

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

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

Myasthenia Gravis

Clinical features: Ptosis, Diplopia (extraoccular muscle weaknss), dysphagia & facial weakness, respiratory failure In some patients: no ocular or facial weakness occurs Fatigable weakness, worse after exertion Fixed proximal myopathy in end stage disease Findings on Investigations: Neurotransmitter related tests: Edraphonium test (Tensilon): 10 mg I.V. (2mg initially & 8mg after 30 seconds) or Neostigmine … Continue reading Myasthenia Gravis

Guillain-Barre Syndrome

Guillain-Barre Syndrome (GBS) is an acute inflammatory polyradiculopathy. It is immune mediated and causes ascending weakness in the limbs, respiratory failure and autonomic instability. Synonyms: Landry-Guillain-Barre-Strohl syndrome Clinical features: Progressive ascending weakness in both legs & arms & areflexia Relative symmetry, autonomic dysfunction, mild sensory symptoms Findings on Investigations: CSF analysis: Albuminocytological dissociation after one … Continue reading Guillain-Barre Syndrome

Tick Paralysis

Tick paralysis also known as Tick bite paralysis is a neuromuscular condition that causes ascending symmetric flaccid paralysis. Clinical features: Prodrome phase followed by weakness Then acute generalised weakness (ascending symmetric flaccid paralysis), involves cranial nerves, usually occurs in children, usually spring or summer. No sensory symptoms +Tick bite or tick attached to skin In … Continue reading Tick Paralysis

Diphtheria Polyneuritis

Diphtheria polyneuritis is a neuromuscular condition that is caused by the bacteria Corynebacterium diphtheriae. It classically causes pharyngitis followed by descending weakness that starts with bulbar weakness and progresses to involve the limbs. Clinical features: Corynebacterium diphtheriae infection: this causes pseudomembrane of the pharynx/tonsils, URI, sore throat Then at 1-2 weeks pharyngeal & laryngeal paralysis, … Continue reading Diphtheria Polyneuritis

Multifocal Motor Neuropathy

Multifocal motor neuropathy (MMN) is a neuromuscular disease that usually presents with asymmetric weakness in a limb. The clinical pattern is that of mononeuropathy multiplex. The condition is treatable.   Clinical features: Asymmetric weakness, usually upper limbs, spares cranial nerves, reflexes may be preserved, fasciculations may occur Note this is a form of mononeuropathy multiplex … Continue reading Multifocal Motor Neuropathy

Nerve diseases

Please start with the section on neuromuscular disease patterns for an introduction. Once you determined that the patient likely has a nerve disease you will need to consider which type to narrow down the differential diagnosis. As described in the previous section determining which of the main patterns cranial neuropathy, mononeuropathy, radiculopathy, polyneuropathy, mononeuropathy multiplex, … Continue reading Nerve diseases

Myopathy (Muscle diseases)

Synonyms: Myopathies, Introduction: Please start with the section on neuromuscular disease patterns for an introduction. Once you determined that the patient likely has a myopathy you will need to consider which type of myopathy to narrow down the differential diagnosis. Clinical features of myopathy: Muscle may be normal, wasted or pseudohypertrophied, depending on the disease … Continue reading Myopathy (Muscle diseases)

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