Pseudochoreoathetosis in four patients with hypesthetic ataxic hemiparesis in a thalamic lesion.

Thalamic lesions give rise to a variety of clinical syndromes including choreoathetotic movements and ataxic hemiparesis as well as sensory deficits. We describe four patients exhibiting pseudochoreoathetosis, hypesthesia, and ataxic hemiparesis in the limbs contralateral to a thalamic lesion. Three of the four patients showed the involuntary movements within 10 days of stroke onset; the remaining patient was not seen until 4 years later. Three had infarction and the other one hemorrhage in the posterior and lateral thalamus. All the patients had both cerebellar and sensory ataxia. These cases suggest that failure to convey proprioceptive information be the basic pathophysiology of pseudochoreoathetosis.