Moyamoya Syndrome Associated with Graves' Disease: A Case Report and Review of the Literature

We report a patient and critically review the literature in order to define the demographic, clinical, neuroradiologic, and treatment features of moyamoya syndrome (MMS) in the setting of Graves' disease (GD). We performed a comprehensive English language Medline search using the keywords “moyamoya,” “Graves' disease,” and “thyrotoxicosis.” We included all patients with angiographic findings consistent with MMS. A 23-year-old woman with active GD presented with intermittent confusion and right arm paresis. Brain magnetic resonance imaging revealed acute left and chronic bilateral hemispheric infarcts. Cerebral angiography revealed multivessel intracranial occlusive disease. Initial treatment with plasmapheresis plus aspirin stabilized the patient's neurologic deficits. Antithyroid treatment plus subsequent surgical encephalomyosynangiosis resulted in prolonged neurologic stability. We studied 30 patients (27 women [90%], 23 of Asian descent [77%]), with a mean age of 29 ± 11.6 years. Hemiparesis (n = 12; 40%) was the leading clinical sign, and ischemic infarction was the most frequent neuroimaging finding (n = 26; 87%). Treatment regimens included antithyroid medications alone (n = 5; 17%), antithyroid plus antiplatelet agents (n = 9; 30%), neurosurgical revascularization after antithyroid medication (n = 11; 37%), and plasmapheresis in the acute thyrotoxic state (n = 2; 7%). Most patients had good short-to-medium term outcome (n = 14; 78% of reported outcome). Plasmapheresis-treated patients achieved neurologic stabilization and had good outcomes. MMS, an infrequent complication of GD, typically affects young women. Our findings indicate that plasmapheresis can stabilize the neurologic picture in the acute phase, and that antithyroid and antiplatelet therapy, combined with revascularization surgery, may improve long-term outcomes. Further work is needed to establish an optimal treatment strategy.