Ataxia

This page is for adult patients. For pediatric patients, see: ataxia (peds).

Background

• Sign of a variety of disease processes; not a diagnosis in itself
• Isolated lesion of cerebellum is NOT the most common cause
• Must distinguish between motor (cerebellar) and sensory (cord, peripheral nerves) ataxia
  • Sensory ataxia may be compensated to a degree with visual sensory information

Clinical Features

• Sensory (failure to transmit proprioception) versus motor (cerebellar) ataxia
  • Romberg test
    • Comparison of posture stability when eyes are open versus eyes closed
    • If ataxia worsens with loss of visual input suggestive of sensory ataxia
    • If ataxia does not significantly change with eyes closed suggests motor ataxia
• Systemic versus isolated nervous system disease
• CNS versus PNS
• Cerebellar versus posterior column (proprioceptive)
  • Finger to nose
    • Performing test with eyes closed tests proprioception
  • Heel-to-shin test
    • Posterior column disease: Difficult locating knee
    • Cerebellar disease: Action completed with series of jerky movements

Differential Diagnosis

• Systemic conditions
  • Intoxications with diminished alertness
    • Ethanol
    • Sedative/hypnotic toxicity
    • Toxic alcohols
    • GHB
    • Benzodiazepine toxicity
    • TCA toxicity
    • Antipsychotic toxicity
    • Inhalant abuse, hydrocarbon toxicity
    • Pentobarbital
    • Chloral hydrate toxicity
    • Marijuana toxicity
    • Phencyclidine toxicity
  • Intoxications with relatively preserved alertness
    • Phenytoin, fosphenytoin, Keppra
    • Carbamazepine, oxcarbazepine
    • Valproic acid
    • Lead, organic mercurials
    • Carbon monoxide
    • Acute radiation syndrome
    • Lithium toxicity
    • Mushroom toxicity
    • Lacosamide
    • Arsenic toxicity
    • Gabapentin
    • Marijuana toxicity
    • Phencyclidine toxicity
    • Lindane
    • Vitamin A toxicity
  • Other metabolic disorders
    • Hyponatremia
    • Hypernatremia
    • Hypomagnesemia
    • Inborn errors of metabolism
    • Wernicke disease
    • Vitamin B7 deficiency
    • Vitamin E deficiency
• Disorders predominantly of the nervous system
  • Conditions affecting predominantly one region of the CNS
    • Hemorrhage, vertebral and carotid artery dissection
    • Infarction
    • Lateral medullary syndrome
      • Degenerative changes
    • Abscess
    • Brain tumor
    • Head trauma
    • Hydrocephalus, normal pressure hydrocephalus, VP shunt malfunction
    • Parkinson's disease
    • Prion disease
    • Heat stroke
    • Leukostasis and hyperleukocytosis
    • Cervical spondylosis
    • Posterior column disorders
  • Conditions affecting predominantly the peripheral nervous system
    • Peripheral neuropathy
    • Vestibulopathy (e.g. vestibular neuritis, labyrinthitis)
    • Guillain-Barre
  • Miscellaneous
    • Acute mountain sickness
    • Syphilis
    • Tick paralysis
    • Ciguatera, neurotoxic shellfish poisoning
    • African trypanosomiasis
    • Tympanic membrane rupture
    • Legionella
    • Paraneoplastic syndromes
      • Postinfectious cerebellitis (acute cerebellar ataxia)
    • Post vaccination (varicella)
    • Vasculitis
    • Epilepsy

Evaluation

• Depends on rapidity of symptoms and additional features
• If acute consider CT, MRI, LP

Management

• Treat underlying pathology

See Also

• Altered Mental Status
• Ataxia (Peds)
• Weakness
• Cerebellar Stroke
• Focal neuro deficits