Facial Nerve Palsy as a Complication of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Report of 3 Cases and Review of Literature.

BACKGROUND: Incidence of chronic subdural hematoma is becoming more frequent due to an aging population in developed countries. Recently, less-invasive alternatives like middle meningeal embolization (MMAE) are gaining popularity. MMAE seems to be a safe, effective, and minimally invasive procedure both as an adjuvant therapy and as a stand-alone treatment. Due to a complex anatomy of the MMA, particular attention should be paid to its anatomical variation, potential anastomotic routes, and identification of the cranial nerve supply from the external carotid artery. Complications like facial nerve palsy, although rare, can occur.

METHODS: We examined medical and radiologic records on a case-by-case basis. We also performed systemic analysis of the available literature.

RESULTS: Three male patients, aged 82, 36, and 87 years, underwent MMAE using Onyx (Medtronic, Minneapolis, MN) as a complementary treatment after burr-hole craniostomy. Each of them developed a complication after MMAE in the form of facial nerve palsy. In the first case the patient was lost to follow-up, in the second facial nerve palsy partially resolved, and in the third the complication was permanent. All of them were treated conservatively.

CONCLUSIONS: Facial nerve palsy after endovascular procedures is a rare condition. The mechanism of the complication in some cases remains unclear. There is no consensus for optimal management of postembolization facial nerve palsy. Treatment protocol should be established. Due to the rare occurrence of this complication, multicenter cooperation should be implemented to explore optimal management.