Ataxia
Subacute onset
Guillain-Barre syndrome
Tick paralysis
Acute onset
Vascular lesion
ADEM
Acute cerebellar ataxia
Sx usually unilateral; accompanied by cranial nerve abnormalities; often associated with headache
Examples: vertebral artery occlusion (including dissection), cerebellar stroke, cavernous angioma, posterior fossa AVM, venous sinus thrombosis
Typical age range: 2-10yo
Accompanied by encephalopathy not explained by fever (= any change in mental status -> irritability, sleepiness, confusion, obtundation)
Post-infectious (especially associated with varicella [or varicella vaccine], EBV)
Associated with lateral gaze nystagmus
Post-infectious (usually 2-3 weeks after infection)
NOT typically accompanied by encephalopathy
Neuroblastoma
Intracranial mass
Ingestion
Postural vertigo (BPPV)
Ethanol
Benadryl
Benzodiazepines
AEDs: phenytoin (especially), phenobarbital, carbamazepine
Look for opsoclonus-myoclonus (but not always present!)
If ataxia is symmetric, consider midline posterior fossa tumor (most common = medulloblastoma)
If mass is significant enough to cause ataxia, there should also be signs of increased ICP
Most common presentation: areflexia with ascending weakness
Variant: areflexia with ataxia (and no weakness/paralysis)
Miller-Fisher variant: ataxia + areflexia + ophthalmoplegia
Self-limiting
Sx worsen over days to weeks
Vestibular neuritis
Post-infectious
Accompanied by nystagmus in one direction
Patients fall toward the affected side
If accompanied by hearing loss -> labrynthitis
Hydrocephalus without a mass can also cause a similar picture
Basilar migraine (can also present acutely)
Conversion disorder (can also present acutely)
MRI shows diffuse, >1-2cm lesions of white matter
Typically accompanied by focal neurological deficits
Affects white matter tracts of the brain, brainstem (which may affect respiratory drive), spinal cord, and optic nerves
Acute inflammatory demyelinating disorder
Peak incidence: 5-6yo
Dextromethorphan
Marijuana