Abstract
A 68-year-old woman with poorly controlled diabetes mellitus presented to the emergency department with choreoathetoid movements affecting the upper and lower left limbs. Computed tomography of the brain did not show any intracranial abnormalities. However, subsequent magnetic resonance (MR) imaging of the brain revealed an increased T1 signal in the right basal ganglia, raising the suspicion of nonketotic hyperglycaemic chorea-hemiballismus. Management consisted of adjusting her insulin dose to achieve good glycaemic control. The patient subsequently recovered and was discharged after eight days. There are many causes of basal ganglia T1 hyperintensity, including hyperglycaemia in patients with poorly controlled diabetes mellitus. This case emphasises the importance of MR imaging in the early diagnosis of hyperglycaemia as a cause of chorea-hemiballismus, to enable early treatment and a better clinical outcome.