Unilateral moyamoya disease with ipsilateral carotid canal hypoplasia: A case report

Abstract

A 41-year-old Korean man was admitted to our hospital with a 1-day history of headache and abnormal left visual field. Neurological examination revealed left homonymous hemianopia and difficulty in fine movement of the left finger. Laboratory studies indicated hyperlipidemia and hyperhomocysteinemia. Diffusion-weighted imaging showed a hyperintense signal on the right posterior cerebral-middle cerebral artery watershed area. Computed tomography angiography and carotid angiography revealed the bottle neck sign on the right internal carotid artery (ICA) with occlusion of the distal right ICA, but not the left ICA. Carotid angiography showed moyamoya vessels as well as occlusion of the distal right ICA. The right carotid canal was hypoplasic. We diagnosed the patient with unilateral moyamoya disease and carotid canal hypoplasia. This case demonstrates that unilateral carotid canal hypoplasia may co-exist with ipsilateral moyamoya disease. A unilateral bottle neck sign may indicate the presence of carotid canal hypoplasia. Evaluation of the bony carotid canal may be useful when it is necessary to distinguish between secondary vascular stenosis due to arteriosclerosis and MMD. Keywords: Moyamoya disease, Carotid canal, Bottle neck sign