A Rare Case of Ischemic Stroke Due to Moyamoya Syndrome Associated with Graves’ Disease in Sub-Saharan Africa

Introduction The coexistence of Moyamoya syndrome and Graves’ disease is rare, particularly in sub-Saharan Africa. We report a case of Moyamoya syndrome associated with Graves’ disease, revealed by an acute ischemic stroke. Patient and observation We present the case of a 45-year-old woman admitted for sudden-onset left-sided hemiparesis and speech impairment. Her medical history included anxiety-depressive disorders, chronic headaches, sleep disturbances, and progressive weight loss. On admission, clinical examination revealed physical asthenia, bilateral pyramidal syndrome, a stage 1 goiter, and regular tachycardia. Brain MRI with angiography showed bilateral FLAIR hyperintensities in the watershed territories of the anterior and middle cerebral arteries, with diffusion restriction and decreased ADC values. Cerebral vascular imaging revealed bilateral occlusion of the terminal internal carotid arteries and middle cerebral arteries, along with narrowing of the anterior, posterior cerebral arteries and the vertebrobasilar system. Cerebrospinal fluid analysis was normal. Ultrasensitive TSH was nearly undetectable. Graves’ disease was suspected based on the presence of hyperthyroidism and significantly elevated anti-TSH receptor antibodies (3.79 IU/L). The vascular lesion pattern observed on cerebral angio-MRI was consistent with stage 1 Moyamoya syndrome according to the Suzuki classification. Conclusion Ischemic strokes are common in Moyamoya syndrome associated with Graves’ disease, particularly in the context of thyrotoxicosis.