Ataxic hemiparesis following thalamic lacunar infarction.

A 60-year-old man developed left hemiparesis and homolateral ataxia with normal sensation and normal somatosensory evoked potentials. A lacunar infarct with gadolinium enhancement in the right dorsolateral part of the thalamus was demonstrated on magnetic resonance imaging. Thalamic lesion is a relatively rare cause of ataxic hemiparesis; most of the reported cases of ataxic hemiparesis caused by thalamic lesion were accompanied by sensory disturbances. This is an interesting case which suggested that the thalamic lesion could be responsible for the ataxic hemiparesis without a sensory disturbance.