Background: Chorea associated with non-ketotic hyperglycemia and high signal intensity lesions on T1-weighted brain magnetic resonance images (C-H-BG) is recognized as a unique syndrome that affects elderly women exclusively. However, its overall clinical features are unclear.
Material and methods: The literature describing patients with C-H-BG from 1985 to 2001 was reviewed using MEDLINE. Their clinical features and those of four patients with C-H-BG at this hospital were analyzed.
Results: This study included 49 patients from the literature and four patients at this hospital. Their mean age at the onset was 71.1 years (range=22-92 years). Women were affected more frequently than men (men/women=17:30). The mean serum glucose level measured after the onset of chorea was 481.5 mg/dl (ranging from 169 to 1264), HbA1c level was 14.4% (ranging from 9.9 to 19.2), and the serum osmolarity was 305.9 mmol/kg (ranging from 291 to 335). Forty-seven patients developed hemichorea. Six patients developed bilateral chorea, and magnetic resonance imaging (MRI) showed bilateral basal ganglia lesions. MRI showed that putamen was involved in all cases (isolated putamen=31 patients, additional basal ganglia lesions=22 patients). None had lesions confined to the caudate nucleus or the globus pallidus. In all, except one, the anterior limb of the internal capsule was spared. Follow-up MRI studies were performed in 22 patients. In most, hemichorea improved along with the disappearance of the lesions. In 39 patients, chorea had ameliorated completely. The remaining 14 cases showed some improvement during the follow-up period. The chorea recurred in seven patients.
Conclusion: C-H-BG is a benign disorder affecting the elderly. It affects men much more frequently than has been reported. The high signal intensity basal ganglia lesion on the T1-weighted brain MRI study was reversible, and correlated with the clinical improvement in chorea.