Proximal clipping of dissecting intracranial vertebral aneurysm--effect of balloon Matas test with neurophysiological monitoring. Case report.

A case of repeated subarachnoid haemorrhage (SAH) caused by rupture of a dissecting intracranial vertebral aneurysm is reported. The clinical manifestations, angiographic findings, pre-operative assessment with neurophysiological monitoring, and surgery are presented. A review of the literature suggests that this type of intracranial aneurysm is being recognized with increasing frequency in SAH and fatality, and therefore exploration and treatment of vertebrobasilar (V-B) dissecting aneurysms is necessary. We emphasize that a balloon Matas test with monitoring of somatosensory evoked potentials (SEP), auditory brain stem responses (ABR), and its wedge pressure in occluding the vertebral artery before operation are objective assessments of treatment for dissecting intracranial vertebral aneurysm.