Tag Archives: PNS


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

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. Clinical features: Peripheral neuropathy Genetics: Autosomal recessive Findings on investigations: Biochemical: Assay of beta galatosylcerebrosidase activity is diagnostic. Electrophysiology/NCS: Peripheral neuropathy Imaging: White matter and grey matter CT: hyperdense in basal ganglia, thalami, corona … 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: Metachromatic leukodystrophy MLD a.k.a. arylsulfatase A deficiency Krabbe disease (Globoid Cell Leukodystrophy) a.k.a. galactocerebroside b-galactosidase deficiency Adrenoleukodystrophy and adrenomyeloneuropathy Alexander disease Canavan disease a.k.a. spongiform degeneration a.k.a. N-acetylaspartatoacylase deficiency Sudanophilic … Continue reading Leukodystrophy

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

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

Idiopathic Cramps

Diagnosis: Cramps occurring without physical examination findings of neurological disease and with normal electrolytes and calcium Clinical features: Cramps occurring without physical examination findings of neurological disease Treatment: Day time cramps: Carbamazepine CBZ P.O. Phenytoin PHT P.O. Nocturnal cramps: Carbamazepine CBZ, Phenytoin PHT, diazepam Note: Quinine P.O. nocte works however risks out-way benefits

Paroxysmal Extreme Pain Disorder PEPD

Synonyms: formerly familial rectal pain syndrome Diagnosis: A type of channelopathy Genetics: Autosomal dominant SCN9A gene. Protein= Nav1.7 voltage gated sodium channel alpha subunit Clinical features: Begins in infancy Autonomic: syncope, bradycardia, skin colour changes (flushing, or harlequin), Tonic nonepileptic seizures Paroxysmal pain: rectal, periorbital or jaw Treatment: Carbamazepine CBZ P.O. Related articles: Neuromuscular disease … Continue reading Paroxysmal Extreme Pain Disorder PEPD

Morvan's fibrillary chorea, Morvan's syndrome, neuromyotonia NMT, and Isaac syndrome

Synonyms: Morvan’s ‘fibrillary chorea’ a.k.a. Morvan’s syndrome, neuromyotonia NMT a.k.a. Isaac syndrome: Both conditions have been described with anti-voltage-gated potassium channel antibodies anti-VGKC (Kv1) VGKC is positive in patients with limbic encephalitis, Morovan’s syndrome. These have different targets. Caspr2: contactin-associated protein-antibody-2, a subtype of VGKC found in Morovan’s syndrome Lgi1: leucine-rich, glioma inactivated 1 protein, … Continue reading Morvan's fibrillary chorea, Morvan's syndrome, neuromyotonia NMT, and Isaac syndrome