Concurrent moyamoya disease and Graves' thyrotoxicosis: case report and literature review.

Coexistence of thyrotoxicosis and moyamoya disease is extremely rare. A 23-year-old woman who had a history of migraine, suffered from frequent right carotid transient ischemic attacks, followed by an ischemic stroke after taking ergotamine for migraine. Magnetic resonance angiography revealed a tubular stenosis of the right internal carotid artery (ICA) and bilateral strictures of the supraclinoid segments of the ICAs. A concomitant thyrotoxicosis was found. A second stroke occurred three weeks later, when the dosage of antithyroid medication was increased and phenylpropanolamine-containing cold remedies were taken. Moyamoya disease was confirmed by cerebral angiography which showed irregular tubular stenosis of the right cervical ICA just above the bifurcation and nearly complete occlusion of bilateral supraclinoid ICAs with collateral flows from posterior circulation. The complexity of the cerebral hemodynamics of this patient is discussed.