Hemichorea secondary to cerebral border zone infarction with middle cerebral artery stenosis: A case report

Abstract

Hemichorea is a rare presentation of stroke. Post-stroke hemichorea is often caused by a lesion affecting the basal ganglia. Herein, we present an unusual case of hemichorea in a patient with border zone infarction and middle cerebral artery stenosis. A 64-year old man visited the emergency department due to acute onset left-sided hemichorea. Brain MRI showed several dot-like multifocal high signal intensities in the right border zone area between the right anterior cerebral artery and the middle cerebral artery. Transfemoral cerebral angiography revealed severe focal stenosis in the right M1 segment. Mechanical thrombectomy was performed and the stenosis partially improved. Computed tomography perfusion showed a delayed mean transit time in the subcortical area around the stroke lesions and no abnormal perfusion defect in the deep structures. Six days after symptom onset, clonazepam was administered, and the chorea ceased. This case highlights that hemichorea can occur in patients with dot-like, scattered stroke lesions in the border zone.