[Ataxic hemiparesis with ipsilateral cheiro-oral syndrome due to a single lacunar infarct at the border between the posterior limb of the internal capsule and the corona radiata].

A patient with ataxic hemiparesis and ipsilateral cheiro-oral dysesthesia (tingling) due to a single lacunar infarct at the border between the posterior limb of the internal capsule and the corona radiata is described. A 47-year-old hypertensive man was admitted because of weakness of the right upper and lower limbs with ipsilateral peri-oral and palmar dysesthesia, which developed during bathing in the morning. Upon admission, neurological examination revealed right hemiparesis with ipsilateral limb ataxia and ipsilateral peri-oral and palmar dysesthesia. Based on neurological finding, he was diagnosed as having ataxic hemiparesis with ipsilateral cheiro-oral syndrome. Brain computed tomography and magnetic resonance imaging demonstrated a small lesion at the border between the posterior limb of the left internal capsule and the corona radiata, which was enhanced with gadolinium-DTPA administration. It has been reported that the disturbance of the cortico-pontine tract causes ataxic hemiparesis and that of the thalamo-cortical projection causes cheiro-oral syndrome. These findings of the present case, therefore, suggest that both of these pathways run closely together at the border between the posterior limb of the internal capsule and the corona radiata.