Diabetic Striatopathy: A Rare Case of Non-ketotic Hyperglycaemia-Induced Hemichorea

Diabetes mellitus is a metabolic condition leading to elevated blood glucose levels due to insulin deficiency, insulin resistance, or a combination of both. Chronically raised blood glucose levels can lead to a broad variety of microvascular and macrovascular complications. Neurological disorders are a common manifestation of diabetes mellitus, and poorly controlled diabetes mellitus frequently causes peripheral sensorimotor polyneuropathy and autonomic neuropathy. More rare manifestations include diabetic amyotrophy and mononeuritis multiplex. Hemichorea-hemiballismus (HCHB) syndrome is a movement disorder in which there is involuntary, high amplitude, low frequency, and irregular movements involving one side of the body and sparing the other. It is a rare condition, and there are many causes such as metabolic, vascular, neoplastic, infective, demyelinating, and traumatic precipitating causes. This report discusses a 63-year-old female who presented with a one-day history of involuntary movements of her left upper and lower limb. On presentation, she was noted to have high-amplitude, low-frequency movements of her left arm and, to a lesser extent, her leg and was significantly hyperglycaemic on presentation. She had a glycated haemoglobin (HbA1c) level of 144 millimole per mol (mmol/mol) and computerised tomography, and magnetic resonance imaging scans of her brain did not identify any abnormalities in the basal ganglia. On control of her blood glucose levels to lower ranges, her involuntary movements resolved, demonstrating a diagnosis of non-ketotic hyperglycaemic hemichorea.