Hemichorea-hemiballism with striatal high signal intensity on T1-weighted images in diabetes

ABSTRACT

Hemichorea-hemiballsim has been reported as a rare Implication of nonketotic hyperglycemia. Recently, Some reports revealed that brain magnetic resonance images of nonketotic hyperglycemic patients with hemichorea-hemiballism showed characteristic contralateral striatal signal abnormality, We present six patients with hemichorea-heniiballism. All of them had diabetes mellitus and performed brain MR images. The MR images of them showed high signal intensity on Tl-weighted images and low signal intensity on T2 weighted images in the striatum contralateal to the involuntary movement. In general, the striatal high signal intensity on TI weighted images are presumed to have developed following hemorrhagic transformation, osmotic myelinolysis, or mild ischemia with reversible deposition of calcium or other material occurred in association with nonketotic hyperglycemia. However the precise mechanism of this signal change is not clear yet and needs pathological confirmation.