Hyperglycemic chorea-ballism or acute exacerbation of Huntington's chorea? Huntington's disease unmasked by diabetic ketoacidosis in type 1 diabetes mellitus.

Content: Hyperglycemic chorea-ballism is predominantly observed in older type 2 diabetic patients, and it is rare in type 1 diabetes and diabetic ketoacidosis (DKA). Huntington's disease (HD) is one of several genetic syndromes associated with diabetes, although the reported prevalence of the association varies. There are few opportunities for most physicians to diagnose early-stage HD.

Objective: We describe bilateral hyperglycemic chorea-ballism in a 40-yr-old female type 1 diabetes patient with DKA and HD.

Setting: The study was conducted in a tertiary care referral hospital.

Results: On admission, the patient exhibited severe involuntary movement of bilateral extremities with DKA, and hyperglycemic chorea-ballism was diagnosed. She recovered from chorea-ballism with admission of fluids and insulin, but mild choreatic movement persisted in the upper extremities. Brain magnetic resonance imaging and DNA analysis revealed HD. Although it has been considered that depletion of striatal γ-aminobutyric acid (GABA) content is rare in DKA, it is largely decreased in HD. Therefore, it is probable that hyperglycemic chorea-ballism or exacerbation of Huntington's chorea resulted from transient depletion of GABA.

Conclusion: The present case provides important insights on the role of GABA in hyperglycemic chorea-ballism and on the clinical issues associated with HD diagnosis.