[Dissecting aneurysm of the posterior cerebellar artery]

Dissecting aneurysms affecting exclusively to the posterior inferior cerebellar artery (PICA) are rare entities. Depending on the dissecting plane of the arterial wall, the clinical manifestations are subarachnoid hemorrhage (SAH) due to rupture or ischemia caused by stenosis or occlusion. Angiographic findings are fusiform dilatation with a narrowing of various degrees proximal to and distal to the fusiform lesion. Magnetic resonance imaging (MRI) can be useful demonstrating the intramural hematoma. We report a 47-year-old man who suffered from SAH. He was neurologicaly intact and vertebral angiography demonstrated and fusiform aneurysm at the origin of the left PICA. He was operated by trapping of the dissecting segment. The patient's postoperative course was uneventful despite of severe vasospasm showed in follow up angiography. Aggressive treatment has been recommended for dissecting aneurysms of the PICA and specially for those presenting with SAH. Both the surgical and endovascular procedures are effective and with good results.