Clinical features of moyamoya disease with Graves' disease: a retrospective study of 394,422 patients with thyroid disease

Moyamoya Syndrome: Differential Diagnosis in Patients With Central Nervous System Symptoms and Hyperthyroidism

Moyamoya syndrome, known as secondary moyamoya disease, is associated with various primary illnesses, such as brain tumor, meningitis, autoimmune disease, and thyrotoxicosis, and their relations are not clear. We report a rare case of moyamoya syndrome in a patient with Graves' disease. An 18-year-old woman was admitted to our hospital due to convulsions. She had symptoms of palpitations and fatiguability for half a year and transient numbness in her left upper extremity and dysarthria for a month. In physical findings, tachycardia and diffuse thyroid swelling were noted. A blood test revealed thyrotoxicosis and antithyroid antibody, and a diagnosis of Graves' disease was obtained. Brain magnetic resonance imaging (MRI) showed bilateral internal carotid artery occlusion. We finally diagnosed the patient with moyamoya syndrome caused by Graves' disease. Moyamoya disease or syndrome can cause symptoms like a stroke, sometimes requiring neurosurgical treatment. In our case, the therapy for Graves' disease resolved the symptoms. When diagnosing moyamoya disease, it is necessary to confirm whether there are any background diseases, such as Graves' disease.

Synergistic Interaction of Thyroid Autoantibodies and Ring Finger Protein 213 Variant in Moyamoya Disease

Recently, thyroid autoantibodies were found to be associated with moyamoya disease (MMD). The ring finger protein 213 (RNF213) p.R4810K variant represents the most important susceptibility genotype of this disease, but its relationship with thyroid autoantibodies remains to be elucidated. Thus, in this study, we aimed to evaluate the clinical relevance of thyroid autoantibodies in each RNF213 genotype in patients with MMD. Included in this study were patients with MMD without a thyroid disease history and in euthyroid status; they were then classified into the mutated or nonmutated based on the RNF213 p.R4810K genotype and positive or negative based on thyroid autoantibody (thyroperoxidase and thyroglobulin) levels. Clinical data of each group were thereafter evaluated. Among the 209 patients, the mutated RNF213 p.R4810K variant and positive thyroid autoantibodies were detected in 155 and 41 patients, respectively. Positive thyroid autoantibodies were found to be more common in the nonmutated patients than in the mutated patients (31.5% vs. 15.5%; P = 0.011). In the mutated patients, as compared to autoantibody-negative patients, autoantibody-positive patients were determined to be more likely to have advanced disease with posterior cerebral artery involvement (54.2% vs. 29.0%; P = 0.017), white matter infarction (58.3% vs. 37.6%; P = 0.046), and a higher modified Rankin Scale at last visit (16.7% vs. 3.1%; P = 0.021). These results suggest that thyroid autoantibodies can act as an immunity inducer in patients with MMD lacking the susceptibility gene RNF213 p.R4810K variant. Moreover, the simultaneous presence of thyroid autoantibodies and the variant seems to aggravate the disease, which indicates synergy between thyroid autoantibodies and the variant.