Concurrent hemichorea and migrainous aura--a perfusion study on the basal ganglia using xenon-computed tomography

A variety of etiologies underlie the neurophysiological imbalance resulting in chorea. We report a 57-year-old woman with a long-history of migraine who suddenly experienced concurrent scintillating scotoma and rapid involuntary movement of her neck and right extremities. Diffusion-weighted magnetic resonance imaging (MRI) failed to detect any fresh ischemic and/or hemorrhagic lesions. Xenon-computed tomography (CT) disclosed gross reduction in the cerebral blood flow (CBF) of the left occipital area. With precise mapping to the brain atlas, extreme hyperperfusion in the motor thalamus was found on the left side. Asymmetrical CBF reduction of the left subthalamic nucleus was also noted. Her symptoms gradually improved and completely disappeared within 15 days. Repeated xenon-CT 1 month post-onset demonstrated normalized CBF in the affected areas. Our study suggests that vascular event underlies the migrainous aura in this case and secondarily provokes a loss of inhibitory control of the motor thalamus resulting in the manifestation of hemichorea.