Abstract
Hemichorea-hemiballismus (HCHB) is a spectrum of involuntary, non-rhythmic movement affecting one side of the body. Although rare, it has been reported as a presenting feature in hyperglycaemic hyperosmolar state (HHS) known in literature as C-H-BG (chorea, hyperglycaemia, basal ganglia) syndrome. We present a case in which the patient presented with 2-day history of right-sided hemichorea preceded by non-compliance to oral hypoglycaemic agent. Investigations revealed marked hyperosmolarity and hyperglycaemia, consistent with HHS. Computed tomography (CT) brain showed non-enhancing hyperdensities at the contralateral putaminal region. The choreiform improved after initiation of treatment for HHS. The hemichorea-hemiballistic movement can be the presenting feature of HHS, diabetic ketoacidosis or uncontrolled diabetes and is completely reversible with timely management. Nevertheless, CT brain plays diagnostic role and important to rule other more sinister aetiologies. The diagnosis of C-H-BG syndrome should be considered in patients with abnormal movement and hyperglycaemia. The symptom can completely recover if the hyperglycaemia is treated accordingly.