Abstract
There are many reasons for patients infected with human immunodeficiency virus (HIV) to develop cerebrovascular disease. The HIV virus itself however may be a cause of vessel wall pathology. We present a clinical and pathological study of a patient who was HIV positive and presented with a subarachnoid haemorrhage. Cerebral angiography and later histology confirm that there was extensive vessel wall injury with dissection and a false aneurysm of the right middle cerebral artery.