Hyperglycaemia Presenting With Hemichorea: A Rare Case of Diabetic Striatopathy With Ketosis

Acute movement disorder is a rare complication of diabetes mellitus. Uncontrolled diabetes mellitus can present with various movement disorders, of which chorea and ballism are the most common. Various nomenclatures have been used in the past for this condition. However, diabetic striatopathy is the most common and comprehensive terminology. It refers to a condition of hyperglycaemia and an acute-onset movement disorder with or without characteristic radiological findings on CT or MRI scan. It is commonly associated with non-ketotic hyperglycaemia in the background of type 2 diabetes mellitus. Previous studies have mostly reported it in the Asian population in the sixth to seventh decades of life with a female predominance. We present an 84-year-old British woman with type 2 diabetes mellitus, atrial fibrillation and suspected primary pancreatic malignancy, who presented after a fall and head injury with a one-week history of choreoathetoid movement of the right forearm and hand. Blood sugars and ketones were raised on presentation. CT and MRI brain demonstrated hyperdensity and T1 hyperintensity in the left basal ganglia, respectively. The patient was treated with variable-rate insulin for a prolonged period, followed by pre-mix insulin. Tetrabenazine was also started. Within one week, there was a dramatic improvement in the choreoathetoid movement. Although increasingly recognised, diabetic striatopathy remains underreported, largely due to limited physician awareness. This case is notable for the unusual association with ketotic hyperglycaemia, advanced age and significant comorbidities. Despite these factors, the patient achieved full recovery, underscoring the importance of early recognition and symptomatic treatment in addition to metabolic correction. Therefore, it should be considered in the list of differential diagnoses in any diabetic patient presenting with a movement disorder, even outside the typical Asian demographic and non-ketotic setting. Prompt diagnosis prevents misclassification as an intra-cerebral haemorrhage and facilitates timely management with an excellent prognosis.