Stenosis of the proximal external carotid artery in an adult with moyamoya disease: moyamoya or atherosclerotic change?

A 55-year-old woman presented with moyamoya disease manifesting as recurrent transient ischemic attacks despite taking aspirin and antihypertensive agent. Angiography showed the characteristic angiographic appearance with bilateral internal carotid artery occlusion and abnormal collateral vessels. Left external carotid angiography demonstrated moderate stenosis of the proximal external carotid artery (ECA). A self-expandable stent was successfully placed in the left ECA to improve ipsilateral cerebral perfusion. The patient had an uneventful outcome after a 1-year follow up. Involvement of the proximal ECA is very unusual in moyamoya disease, and might result from hemodynamic stress or degenerative atherosclerosis. Revascularization procedures for stenoses of proximal ECA may improve cerebral perfusion in patients with moyamoya disease.