[Cerebral peduncle infarction with pure dysarthria--case report].

A 82 year-old male having a long history of hypertension was admitted for dysarthria. Neurological examination revealed dysarthria with mild disturbance of left-sided soft palate elevation. No lingual palsy nor facial weakness were noted. No motor weakness in the upper and lower extremities was noted. Diffusion-weighted image and T2 weighted image revealed a small high signal lesion localized in the medial one-third of the left cerebral peduncle. There were bilateral stenotic lesions of the posterior cerebral artery at P1 portion in intracranial magnetic resonance angiography. Pure dysarthria can be caused by disruption of the supranuclear fiber of glossopharyngeal and vagal nerve nucleus in the corticobulbar tract, which can be localized in the medial portion of the cerebral peduncle.