Nonketotic Hyperglycemia Presenting as Hemichoreoballism: A Case Report of an Older Woman with Diabetes

Nonketotic hyperglycemic hemichoreoballism, also known as chorea, hyperglycemia, and basal ganglia syndrome, is a rare neurological manifestation of poorly controlled diabetes.This report describes the case of an 81-year-old woman with a 25-year history of diabetes who developed choreoballism.She exhibited continuous, involuntary, arrhythmic, and purposeless movements of the left limbs.Laboratory results revealed marked hyperosmolar hyperglycemia, with a random blood glucose level of >600 mg/dL, serum osmolality of 308 mOsm/kg, and a glycated hemoglobin A1c level of 12.9%.T1-weighted brain magnetic resonance imaging revealed high-signal intensities in the right putamen, a part of the basal ganglia.The unusual movements resolved after glucose levels were normalized and haloperidol was administered.Although the exact pathophysiology and clinical features of this condition remain unclear, it generally carries a favorable prognosis.