Putaminal changes before the onset of clinical symptoms in diabetic hemichorea-hemiballism.

An 81-year-old woman with poorly controlled diabetes mellitus was hospitalized due to hemichorea-hemiballism. A radiological examination revealed typical putaminal changes of diabetic hemichorea-hemiballism (DHC-HB). Interestingly, brain computed tomography, performed before symptom onset, disclosed a hyperdense lesion in the left basal ganglia, indicating persistent basal ganglia impairment, even before the onset of symptoms, under sustained hyperglycemia. Additionally, an increase in the cerebrospinal fluid level of homovanillic acid was related to the symptom appearance of DHC-HB. Pronounced potential basal ganglia impairment under hyperglycemia and central dopaminergic hyperactivity was important for the development of DHC-HB in this patient.