MON-652 Rhabdomyolysis Secondary To Refractory Hemichorea In The Setting Of Nonketotic Hyperglycemia

Abstract Disclosure: S. Benjamin: None. K. Shams: None. M.H. Horani: None. A. Samuel: None. Background: Hemiballismus-hemichorea (HH) is a rare hyperkinetic movement disorder associated with nonketotic hyperglycemia. Although often self-limiting with glycemic control, prolonged and refractory symptoms are uncommon and rarely lead to rhabdomyolysis. Case Presentation: A 53-year-old female with type 2 diabetes mellitus presented with one week of choreoathetoid movements of the right upper extremity, with minor right lower extremity involvement. She had been off antidiabetic medications for over one year due to insurance limitations. Upon evaluation, head CT was unremarkable, labs showed glucose 409 mg/dL, bicarbonate 19 mmol/L, anion gap 20, BHB 8 mmol/L, C-peptide 0.8 ng/mL, and A1c >14%. Notably, creatinine was 1.48 mg/dL and CK elevated at 8,447 U/L. Imaging revealed basal ganglia hyperdensity, consistent with nonketotic hyperglycemia. MRI and MRA were limited by motion artifact and the patient declined repeat imaging with sedation. EEG showed no epileptiform activity. Despite insulin initiation and improving glycemic control, hemichorea persisted for several days, contributing to marked muscle overuse and resulting rhabdomyolysis. A combination of olanzapine and topiramate eventually led to significant motor symptom resolution. CK levels normalized with resolution of HH. Discussion: This case underscores the importance of recognizing rhabdomyolysis as a rare but potential complication of HH when symptoms are prolonged/refractory. While HH is usually reversible with glycemic control, sustained involuntary movements can result in metabolic complications including muscle breakdown. The patient’s elevated CK, renal dysfunction, and persistent chorea highlight this rare but serious complication. Conclusion: Refractory hemichorea secondary to nonketotic hyperglycemia can lead to rhabdomyolysis, a rare but clinically significant consequence. Multidisciplinary management and early recognition are key to avoiding systemic complications. This case also reinforces the importance of treatment access and adherence in chronic disease management. Presentation: Monday, July 14, 2025