J. Oh

SUMMARY: Hemiballism with corresponding striatal T1 hyperintensity on MR imaging has occasionally been reported in patients with nonketotic hyperglycemia. However, the subthalamic nucleus lesion, which is believed to be pathogenetically related to hemiballism, is rarely documented in a living patient with nonketotic hyperglycemia. We describe a patient with nonketotic hyperglycemia-induced hemi-ballism, whose responsible lesion (ie, the subthalamus) was demonstrated by MR imaging. Hemiballism-hemichorea (HB-HC) is an involuntary, ir-regular, wide-amplitude, and poorly patterned move-ment disorder. HB-HC canmostly result from a focal vascular lesion in the contralateral basal ganglia.1 In the absence of an identifiable focal vascular lesion,metabolic derangements (eg, nonketotic hyperglycemia or hyperthyroidism), brain neo-plasm, and infectious diseases of the central nervous system (eg, human immunodeficiency virus infection) are considered to be the more common causes.1 Recent studies have shown that striatal hyperintensity, seen on the T1-weighted MR im-aging of the brain, can occur in the acute stage of HB-HC