Ataxia

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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 versus motor 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-hypnotics
    • Intoxications with relatively preserved alertness
      • Phenytoin
      • Carbamazepine
      • Valproic acid
      • Lead, organic mercurials
    • Other metabolic disorders
      • Hyponatremia
      • Inborn errors of metabolism
      • Wernicke's disease
  • Disorders predominantly of the nervous system
    • Conditions affecting predominantly one region of the CNS
      • Cerebellum
        • Hemorrhage
        • Infarction
        • Degenerative changes
        • Abscess
      • Cortex
        • Frontal tumor, hemorrhage, or trauma
        • Hydrocephalus
      • Subcortical
        • Thalamic infarction or hemorrhage
        • Parkinson's disease
        • Normal pressure hydrocephalus
      • Spinal cord
        • Cervical spondylosis
        • Posterior column disorders
    • Conditions affecting predominantly the peripheral nervous system
      • Peripheral neuropathy
      • Vestibulopathy

Evaluation

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

Management

Disposition

See Also

References