Non-ketotic hyperglycemia in a young woman, presenting as hemiballism-hemichorea

We report a 22-year-old girl presenting with acute onset left sided hemiballism-hemichorea (HH) and non-ketotic hyperglycemia (NKH). Initial brain CT revealed faint hyperdensities, sharply confined to the contralateral nucleus caudatus and putamen. Sequential MRI investigations yielded increasing hypersignal intensities on T1-weighted images and resolving hypodensities on T2-weighted images of the right striatum, leaving small sequelae in the head of the right caudate nucleus. NKH is an unusual cause of HH. The abnormalities seen in neuroimaging are rare, but seem to be quite specific to this syndrome. We give an update on current literature regarding the possible pathophysiological processes underlying this specific clinical entity.