Presentation of striatal hyperintensity on T1-weighted MRI in patients with hemiballism-hemichorea caused by non-ketotic hyperglycemia: report of seven new cases and a review of literature.

Recent studies have shown unique clinicoradiologic characteristics in patients with hemiballism-hemichorea (HB-HC) caused by non-ketotic hyperglycemia; however, there is still a limited number of patients being reported. We report 7 patients (3 males and 4 females) with this type of dyskinesia, whose ages ranged from 60 to 84 years. Brain CT of these patients showed hyperdensity in the contralateral striatum, corresponding with MRI studies that showed an increased signal intensity on T1-weighted images and a decreased signal on T2-weighted images. After metabolic control had been achieved, the hyperkinetic state of these patients abruptly ceased. Follow-up neuroimaging studies in 2 patients documentied complete resolution of the striatal hyperintensity on brain CT and MRI after 3 months and 6 months, respectively. A review of patients with HB-HC caused by non-ketotic hyperglycemia reported formerly and in the present study shows that the dyskinesia tends to occur in aged diabetic patients. The age of patients with dyskinesia secondary to cerebral infarction is generelly much lower. We also found that 86% (30 out of 35 cases) patients reported with HB-HC caused by non-ketotic hyperglycemia were Asians. The prognosis of the dyskinesia was excellent, and the radiological abnormalities are completely reversible.