The role of vertebral angiography in the investigation of third nerve palsy.

Abstract
The association between intracranial aneurysm and 3rd nerve palsy in a series of 50 patients over a 6 year period was studied. All aneurysms causing a 3rd nerve palsy were in the anterior circulation and all were adequately demonstrated by carotid angiography alone. None of the 30 cases of posterior circulation aneurysm was associated with a 3rd nerve palsy. Vertebral angiography carries a higher risk of serious complication than carotid angiography. The added risk of vertebral angiography is not justified for the investigation of an isolated 3rd nerve palsy.