Persistent hemiballism with striatal hyperintensity on T1-weighted MRI in a diabetic patient: a 6-year follow-up study.

The combination of hemiballism, hyperglycemia and hyperintensity of the striatum on T1-weighted MRI constitutes a unique syndrome. We report the follow-up of a patient with this disorder whose hemiballism was sustained for over 5 years. High density on CT of the right striatum turned into normodensity in 4 months, and hyperintensity on T1-weighted MRI and hypointensity on T2-weighted MRI of the lesion were resolved in 18 months. A decreased perfusion of the lesion by SPECT remained 37 months after onset. There was no volume change of the lesion during the course of the illness. The radiological features support the possible pathology of either or both petechial hemorrhage and astrocytosis with high protein concentration after ischemic insult. The hemiballism may result from selective damage of GABA/enkephalin-containing neurons in the striatum and can persist without the primary histological changes causing the striatal T1-hyperintensity in this disorder.