Subarachnoid haemorrhage due to a dissecting aneurysm of the anterior cerebral artery: a case report.

Dissecting aneurysms of the intracranial carotid circulation are becoming increasingly recognised as a cause of subarachnoid haemorrhage. We present a case where SAH caused by anterior cerebral artery dissection was diagnosed on a repeat angiogram and successfully treated by surgical trapping. Diagnosis may be difficult as angiographic signs may be subtle and variable. Accurate diagnosis and prompt treatment is important, as the re-bleed rate is high.