Abstract 2786: Moyamoya Syndrome Associated With Graves' Disease: Report Of 16 Cases

Abstract

Background and purpose Moyamoya disease is a cerebrovascular disorder characterized by bilateral progressive stenosis and occlusion of terminal portions of internal carotid artery (ICA) accompanying by typical net-like collateral vessels. Patients with both the characteristic moyamoya vasculopathy and the associated conditions are categorized as moyamoya syndrome. These conditions include sickle cell disease, neurofibromatosis type 1, Down’s disease, cranial therapeutic irradiation and other rare diseases. Moyamoya syndrome associated with Graves’ disease has been rarely reported and the underlying coexisting mechanism remains unclear. The aim of this study is to identify the clinical and radiological findings of the patients with simultaneous diagnosis of moyamoya syndrome and Graves’ disease. Possible mechanisms predisposing these individuals to ischemic accidents are discussed. Methods We retrospectively identified 12 patients in Peking Union Medical College Hospital and 4 patients in 307 hospital of PLA between May 2000 and December 2010. All patients were female and mean age (range) was 35.13±12.34 years (11-57 years). The patients were diagnosed with Graves’ disease in endocrinology clinic which meet the full diagnostic criteria and no atherosclerotic factor was found in them. Moyamoya vasculopathy was definitely or probably diagnosed by digital subtract angiography or magnetic resonance angiography. The clinical characteristics and prognosis, laboratory data, vascular radiological characteristics were all collected. Results Stenosis or occlusion of bilateral distal ICA and/or proximal anterior /middle cerebral arteries was found in 13 patients. Three patients had unilateral distal ICA stenosis and abnormal collateral vessels. PCA stenosis was found in 2 patients. Fifteen patients presented with infarction or transient ischemic attack and one with dizziness. Interestingly, thyroid function tests demonstrated predominantly elevated thyroxine and suppressed thyroid stimulating hormone level in 15 patients when cerebrovascular accidents occurred. All patients received antithyroid therapy and two had recurrent ischemic attack after several months of drug withdrawal. Four patients underwent revascularization procedures after normalization of their hormonal conditions in 307 Hospital of PLA and their neurologic status has remained stable during follow-up. Conclusions: Compared with classical moyamoya disease, moyamoya syndrome associated Graves’ disease more commonly presented asymmetric stenosis or occlusion and PCA lesions. Cerebrovascular hemodynamic changes attributable to thyrotoxicosis might be responsible for ischemic attack and further studies are required to verify this hypothesis.