Moyamoya phenomenon following clipping of intracranial aneurysm: case report.

Subarachnoid haemorrhage from aneurysmal rupture is a common emergency in neurosurgery. Depending on aneurysm position, morphology, size, associated clot, and symptoms, it is either managed by endovascular occlusion or by clipping. Here we report the first known case of secondary Moyamoya phenomenon following the clipping of a supraclinoid internal carotid artery Aneurysm. After making a complete recovery following clipping, this patient developed headaches 6 years later. Angiographic imaging revealing Moyamoya phenomenon characterized by total distal arterial occlusion and development of anastomotic collaterals. This phenomenon may be caused by neuroinflammation and suggests a tailored neuroimaging follow-up is required for such patients.