Dissecting aneurysms of the posterior inferior cerebellar artery: report of four cases and review of the literature

Dissecting aneurysms frequently involve the vertebral arteries and their br anches, but those exclusively on the posterior inferior cerebellar artery ( PICA) represent only 24 cases in the literature, including the four cases d iscussed in this article. The clinical diagnosis tacks pathognomonic signs or symptoms, with presentations such as subarachnoid haemorrhage or ischaem ia of the brain stem or the cerebellum, and the management is controversial . Wrapping, clipping and embolisation of the aneurysms were tried in this s eries with different outcomes. Exclusion of the pathological segment should be performed, as shown by rebleeding from our case which was wrapped or by progression of the vascular disease in cases where treatment was delayed. Surgical or endovascular occlusion are well tolerated in our cases and in t hose reported from the literature, which implies the absence of normal perf orating branches to the brain stem arising from the proximal dissected segm ent of the PICA and a good collateral circulation. A revascularisation proc edure using the occipital artery can be performed in order to prevent infar ction if an endovascular test occlusion is not tolerated. (C) 2000 Harcourt Publishers Ltd.