Pure dysarthriaを呈した大脳脚梗塞の1例

Cerebral Peduncle Infarction with Pure Dysarthria―Case Report

緒言

　1983年にFisherは構音障害だけを生じるラクナ症候群をpure dysarthriaと呼んだが，これらの神経症候を生じる責任病変としては現在までに大脳皮質，放線冠，内包膝部，後脚，橋底部，小脳虫部などが指摘されている^1－8）。大脳脚の限局性梗塞によるpure dysarthriaの報告は本例が初めてであり，構音障害の責任病変部位からその機序と大脳脚における皮質延髄路の局在について考察した。

Abstract

　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.