Dancing Limbs, Silent Hyperglycemia: Hemiballismus Revealing Hyperosmolar Hyperglycemic State

Hemiballismus Revealing Hyperosmolar Hyperglycemic State

Abstract

Hemiballismus is a rare hyperkinetic movement disorder classically associated with structural lesions of the basal ganglia, but it may also represent a reversible manifestation of severe metabolic disturbances, particularly hyperglycemia. We report the case of a 68-year-old man with type 2 diabetes mellitus who presented with a two-week history of progressive gait impairment due to unilateral involuntary movements. Laboratory evaluation revealed severe hyperglycemia, hyperosmolarity, acute kidney injury, and electrolyte disturbances, consistent with hyperosmolar hyperglycemic state. Brain computed tomography showed no acute structural lesions. Following metabolic correction with intravenous fluids and insulin therapy, rapid and sustained neurological improvement was observed. This case highlights hemiballismus as an initial and potentially misleading manifestation of severe hyperglycemia, emphasizing the importance of systematic metabolic assessment in patients presenting with acute or subacute movement disorders that may mimic cerebrovascular disease.