Resolving the Dance: A Case Study on Non-Ketotic Hyperglycemic Hemichorea-Hemiballismus in a Patient with Long-Standing Type 2 Diabetes.

BACKGROUND Non-ketotic hyperglycemic hemichorea-hemiballism (HCHB) is a rare complication of diabetes, which is mainly described in case reports. This condition occurs more commonly in older women and is known to be associated with T1 hyperintensity basal ganglia lesions on magnetic resonance imaging (MRI). The pathophysiology of non-ketotic hyperglycemic HCHB is not well defined, although a combination of regional metabolic failure and ischemia due to hyperglycemia is suspected to occur. Treatment entails tight blood glucose control, although antipsychotic medications such as risperidone may be helpful in refractory cases. CASE REPORT We describe a case of a middle-aged man with long-standing type 2 diabetes who experienced 3 weeks of progressive unilateral arm, leg, and face choreiform movements. Laboratory testing performed just prior to symptom onset was notable for a hemoglobin A1C of >15% and a serum blood glucose of 566 mg/dl. MRI revealed diffuse T1 hyperintensity in the left lentiform nucleus. Our patient's insulin regimen was adjusted, resulting in improvement in average serum glucose (A1C of 9.4%). However, his symptoms did not improve significantly. A trial of benzodiazepine was attempted, without success. When risperidone was started, the patient experienced resolution of symptoms. Recurrence of non-ketotic hyperglycemic HCHB while off risperidone has not occurred to date. CONCLUSIONS Non-ketotic hyperglycemic HCHB is a rare but important diagnosis to consider in patients with hyperglycemia and new-onset choreiform movements. Patients with long-standing type 2 diabetes may be affected, especially when glycemic control worsens. When tight blood glucose control does not resolve symptoms, a short course of antipsychotic agents may provide relief.