Hemichorea as the Initial Presentation of Graves' Disease

Chorea is a hyperkinetic movement disorder characterized by involuntary, spontaneous, irregular, purposeless movements that flow unpredictably from one body part to another. An overlap between movement disorders and neuroendocrine abnormalities is widely recognized; however, chorea is a rare complication of hyperthyroidism. In this case report, we present a case of unilateral upper limb chorea as a manifestation of hyperthyroidism. We describe a clinical case of a 21-year-old male who presented repeatedly to the emergency department (ED) with acute-onset, involuntary proximal movements of the left upper limb (LUL), arrhythmic in nature, without involvement of the face, trunk, or lower limbs (LLs). Neurological examination and investigations (cerebral magnetic resonance imaging, electroencephalogram, cerebral computed tomography angiography, and lumbar puncture) were unremarkable, except for the involuntary purposeless movements previously mentioned. During a subsequent admission for recurrent symptoms, the patient was diagnosed with acute appendicitis. Concurrent laboratory evaluation revealed thyrotoxicosis with suppressed TSH, elevated free T4 and T3, and positive TSH-receptor antibodies, confirming Graves' disease. Surgical intervention was postponed due to the risk of thyroid storm, and the patient was admitted to the intensive care unit for stabilization and initiation of antithyroid therapy. Treatment with methimazole, propranolol, cholestyramine, hydrocortisone, and Lugol's iodine led to normalization of thyroid function and complete resolution of hemichorea on follow-up, supporting a causal link to thyrotoxicosis. Hemichorea is rare in patients with hyperthyroidism, but it can be the first manifestation of the condition. This clinical case draws attention to an atypical presentation of Graves' disease and its challenges. This initial presentation may experience a delayed diagnosis, as hyperthyroidism is not typically the first consideration, and usually presents with other symptoms, such as palpitations, weight loss, heat intolerance, irritability, proptosis, and hyperhidrosis. Early recognition and proper diagnosis are essential, as treating the underlying disease may lead to rapid resolution of chorea and avoid unnecessary treatments.