Hemichorea-hemiballism in primary diabetic patients: MR correlation

Purpose: The purpose of this work was to describe the characteristic imaging findings and clinical presentations in patients with hemichorea-herniballism (HC-HB) associated with nonketotic hyperglycemia (NKH) in primary diabetes mellitus (DM). Method: The MR findings from six patients with HC-HB associated with NKH in primary DM were evaluated. Their ages ranged from 43 to 81 years. CT was performed on three patients, one of whom underwent a SPECT exam and another who had follow-up MRI. Results: A high-signal putaminal lesion was evident on the T1-weighted images in all cases without edema or mass effect. Three of the six cases also showed high-signalintensities in the caudate. Two cases revealed high-signal intensities in the globus pallidus, and the lesions extended to the midbrain in one patient. The T2-weighted and FLAIR images were more variable. One diffusion-weighted image showed increased signal intensity. All three patients who had postcontrast MRI showed no enhancement. Two of the three patients who had CT studies showed high attenuation and the other isodensity. The SPECT study showed decreased perfusion. In all our patients. the chorea resolved within days to weeks after correction of the underlying hyperglycemia. Conclusion: In patients with HC-HB with NKH in primary DM, T1-weighted MR images showed hyperintense lesions of the putamen or caudate. Early recognition of these imaging characteristics may facilitate the diagnosis of primary DM with hyperglycemia and lead to prompt and appropriate therapy.