Acute Thyrotoxicosis of Graves Disease Associated with Moyamoya Vasculopathy and Stroke in Latin American Women: A Case Series and Review of the Literature

Objective Moyamoya disease is a cerebral vasculopathy characterized by stenosis of the terminal internal carotid artery, proximal middle cerebral artery, and anterior cerebral artery. There is an association between moyamoya vasculopathy and Graves disease, primarily in Asian populations. Here, we present the largest series of non-Asian, predominantly Latino patients with moyamoya vasculopathy in the setting of Graves thyrotoxicosis, as well as the largest review of the literature to date. Methods We retrospectively analyzed patients presenting with stroke in the setting of clinical Graves disease to our institution from 2004 to 2014. Moyamoya vasculopathy was diagnosed by magnetic resonance angiography in all patients. Results Eight patients with Graves disease thyrotoxicosis and moyamoya vasculopathy were identified. Six patients were effectively managed with aggressive medical management using antithyroid and antiplatelet medications. No recurrent strokes were noted once thyrotoxicosis was controlled. Intracranial bypass was necessary in 2 patients who failed medical management. Seventy-nine additional cases were reported from the literature. There was no significant difference in clinical improvement between medical therapy alone and medical therapy with neurosurgical prophylaxis (87.0% vs. 88.0%, respectively; P = 0.94). Conclusions Moyamoya vasculopathy associated with Graves disease thyrotoxicosis in non-Asian women may be more common than previously thought. In addition, our series suggests that thyrotoxicosis promotes the progression of vasculopathy. Based on our review, there is no significant difference in clinical improvement between proper medical and surgical therapies. Aggressive medical therapy should be considered first-line treatment for moyamoya vasculopathy with Graves thyrotoxicosis, with neurosurgical rescue reserved for medically refractory cases.