Ataxic hemiparesis following thalamic infarction.

We describe a 73-year-old man with ataxic hemiparesis following infarction of the ventrolateral nucleus of the thalamus demonstrated by computed tomography and magnetic resonance imaging. Cerebellar ataxia was most likely due to interruption of the dentatorubrothalamocortical fibers at the level of the injured ventrolateral nucleus. Hemiparesis was probably caused by local edema compressing the corticospinal tract in the adjacent posterior limb of the internal capsule. We believe this to be the first reported case of classic ataxic hemiparesis following thalamic infarction.