[Abnormal MR findings in the temporal lobe and basal ganglia along with vasospasm in a case of hemiballism associated with diabetes mellitus].

A 46-year-old woman with a nine-year history of diabetes mellitus (DM) without treatment had an acute onset of right hemiballism. For the treatment of hyperglycemia (random blood sugar 588 mg/dl) conventional insulin therapy was started, and HbA1c rapidly decreased from 16.3% to 8.8% over the first two months. During this period, there were no hypoglycemic symptoms or episodes, though amnesia appeared just after the insulin therapy was started. T1-weighted MRI showed hyperintensity in the left basal ganglia, which has been reported in many cases of chorea or ballism associated with DM. In addition, there were unique changes in the left temporal lobe, including transient contrast enhancement along the cortex followed by transient hyperintensity in the cortical-subcortical area on T2 weighted and FLAIR images, and then hyperintensity along the cortex on T1 weighted images and atrophy. These findings were thought to indicate a consecutive process, i.e., capillary hyperlucency followed mainly by vasogenic edema and then laminar necrosis. Similar MR findings were reported in hypoglycemic coma. MRA also revealed a transient vasospasm in the left MCA M1-M2 portions in this patient. These signal changes may have been related to the prolonged hyperglycemic state as well as blood sugar control that was too rapid.