Failure to produce smooth intentional movements. Is either sensory abnormality (due to peripheral nerves, spinal cord, or cerebellar input tracts) or motor abnormality (cerebellum).
Always walk your patient if you can with any neuro complaint.
Rapid thigh-slapping test: examines for dysdiadochokinesia or clumsy rapid movements. Have patient slap thigh with palm and then the back of the hand rapidly as fast as possible. Looks for lateral cerebellum dysfunction.
Finger-to-nose test: helpful for distingushing between cerebellar and posterior column (proprioception) by having them close their eyes (proprioception).
Heel-to-shin test: Cerebellar function in the lower extremities.
Stewart-Holmes rebound sign: sudden release of the flexed forearm, the individual fails to check the movement.
Romberg Test: standing with arms outstretched and eyes open. Look for unsteadiness – if present, has some ataxia. Have them close their eyes while doing it – if theres a large change in unsteadiness, romberg sign positive and suggests sensory ataxia such as posterior column/vestibular dysfunction or peripheral neuropathy.
Systemic disorders: intoxication with diminished alertness (alcohol, sedative-hypnotics), intoxication with preserved alertness (phenytoin, carbamazepine, valproic acid, heavy metals), metabolic disorders (hyponatremia, wernicke’s disease).
Local CNS disorders: cerebellum (hemorrhage, infarction, degenerative changes, abscess), cortex (frontal tumor, hemorrhage or trauma, hydrocephalus), subcortical (thalamic infarction or hemorrhage, parkinson’s disease, NPH), spinal cord (cervical spondylosis, posterior column disorders).
Peripheral Nervous System disorders: peripheral neuropathy (B12, folate), vestibulopathy.
Ataxia in Children
Drug Ingestion: Ethanol, phenytoin, carbamazapine, sedatives, lead, mercury.
Idiopathic: acute cerebellar ataxia of childhood (post infectious demyelinating disorder with onset of gait ataxia, occasional fever).
Infection and Inflammation: Varicella, Coxsackervirus A/B, Mycoplasma, Echovirus, Postinfectious Inflammation, Postimmunization.
Neoplasm: Neuroblastoma, CNS tumor.
Paraneoplasm: Opsoclonus-myclonus syndrome.
Trauma: SDH or EDH.
Congential or herediatry: Pyruvate decarboxylas deficiency, Friedreich’s ataxia, Hartnup disease.
Others: hydrocephalus, cerebellar abscess, labyrinithis, vestibular neuronitis, transverse myositis, meningoencephalitis.
Tintinalli, Chapter 163: Ataxia and Gait Disturbances