[A rare neurologic syndrome due to a common medical condition].

We describe a patient with hypertension, diabetes mellitus, recurrent strokes, congestive heart failure, chronic atrial fibrillation and renal failure,who was hospitalized twice for chorea. A thorough work-up excluded all common causes for chorea in the elderly. The patient's HbA1c was > 17% and the brain computerized tomography revealed dense lesions in the basal ganglia compatible with Chorea Hyperglycemia Basal Ganglia syndrome. This syndrome includes a combination of chorea, hyperglycemia and dense lesions in the basal ganglia. The hemichorea in this syndrome is provoked by non-ketotic hyperglycemia and improves with insulin treatment. The radiographic picture also improves after there is control of glucose levels and clinical improvement.