Ataxic hemiparesis due to small semioval center infarction--consideration of the neuroanatomical disruptions responsible for ataxic hemiparesis.

A 63-year-old man with clinical features of typical ataxic hemiparesis is reported. CT scan and magnetic resonance imaging showed a small infarction in the contralateral semioval center near the parietal cortex. Of note is the previously unreported site of the lesion relative to this syndrome. The neuroanatomical basis for the ataxic hemiparesis syndrome is discussed.