小脳橋角症候群をきたした後下小脳動脈動脈瘤症例

Cerebellopontine Angle Syndrome due to an Aneurysm of Posterior Inferior Cerebellar Artery:Report of a Case

緒言

　小脳橋角症候群をきたす疾患としては，聴神経腫瘍が代表的であるが，その他の種々の腫瘍性，非腫瘍性病変によっても同様の症候が惹起され得ることが知られている。われわれは，血管性病変の一つである後下小脳動脈（PICA）動脈瘤によって小脳橋角症候群を呈した症例を経験し，神経耳科学的に精査する機会を得たので，考察を加え報告する。

In a 75-year-old woman, audiological examina-tions showed a mild sensorineural hearing loss in her left ear, suggesting of a retrocochlear lesions. Auditory brainstem response showed the disap-pearance of wave V. Neurotological examinations showed cerebellar and brainstem deficits.

CT showed a high density area with contrast medium near the left cerebellopontine angle. And the angiography of left vertebral artery revealed an aneurysm of the posterior inferior cerebellar artery.

The literature concerning cerebellopontine angle syndrome was reviewed, and the mechanism of cerebellopontine angle syndrome produced by an aneurysm was discussed.