くも膜下出血と小脳梗塞を同時に発症した椎骨動脈-後下小脳動脈解離性動脈瘤の1例  [in Japanese] A Case of Dissecting Aneurysm of Vertebral Artery-Posterior Inferior Cerebellar Artery with Subarachnoid Hemorrhage and Cerebellar Infarction Coincidentally  [in Japanese]

We report a case of dissecting aneurysm of the vertebral artery (VA)-posterior inferior cerebellar artery (PICA) with subarachnoid hemorrhage (SAH) and cerebellar infarction coincidentally. A 40-year-old man presented with severe cervical pain with subsequent serious disturbance of consciousness. CT on admission showed SAH mainly in the posterior fossa, and magnetic resonance imaging (MRI) revealed acute infarction in the left cerebellar hemisphere. Angiography, 3D CT angiography and MRI showed no obvious bleeding source. He underwent suboccipital external decompression due to progressive brain edema resulting from the cerebellar infarction. Three weeks later, follow-up angiography revealed a stenotic lesion at the left PICA. Proximal clipping of the left VA proximal to the left PICA was planned under the diagnosis of a dissecting aneurysm. Intraoperative findings revealed an aneurysm at the left VA proximal to the left PICA. The aneurysm dome had a surface dimple with circumferential hematoma, which seemed to be the bleeding source. Trapping of the aneurysm was performed. The patient was discharged with slight cerebellar ataxia. We suggest that some dissecting vertebral aneurysms may induce subarachnoid hemorrhage and infarction coincidentally.