Somatosensory evoked potentials in lacunar syndromes of pure motor and ataxic hemiparesis.

Syndromes of hemiparetic lacunar infarction include pure motor hemiparesis and ataxic hemiparesis. Twelve such patients were evaluated with somatosensory evoked potentials. Potentials were delayed or absent in all 4 patients with ataxic hemiparesis and in 1 of 8 patients with pure motor hemiparesis. Unlike pure motor hemiparesis, ataxic hemiparesis appears to be associated with abnormal somatosensory evoked potentials. These abnormalities suggest that disturbance of afferent pathways are important in ataxic hemiparesis.