Hemiballism, a rare complication of coil embilization.

Thromboembolism is one of the major complications during coil embolization of an aneurysm, which usually causes familiar neurological deficits, such as, weakness, aphasia, etc. We report a rare complication by thromboembolism after coil embolization causing hemiballism. A 69-year-old female presented with unruptured posterior communicating artery aneurysm and was treated by coil embolization. After the procedure, the patient showed global aphasia and right hemiparesis, and there were small multiple, scattered infarctions on the left middle cerebral artery territory. The neurologic deficit subsided after five days, but hemballism occurred thereafter. There was no other medical history to explain the hemiballism. The patient was treated with clonazepam and antiepileptics and the hemiballism subsided at postoperative day 20. We report a case of rare complication, hemiballism, during coil embolization.