Nakazaki Asuka, Yamaguchi Shigeru, Motegi Hiroaki, Ishi Yukitomo, Okamoto Michinari, Fujimura Miki
Department of Neurosurgery, Faculty of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
NMC Case Rep J. 2022 Jul 19;9:213-216. doi: 10.2176/jns-nmc.2022-0117. eCollection 2022.
Facial nerve function improvement is a challenging goal in facial nerve schwannoma (FNS) surgery. Intraoperative continuous monitoring of evoked facial nerve electromyograms (CFN-EMGs) is performed in acoustic neuroma surgery to preserve facial nerve function. CFN-EMGs were applied in decompression surgery for FNS with severe facial paresis. A 39-year-old woman presented with a sudden onset of vertigo, left hearing disturbance, and severe left facial palsy with House-Brackmann (HB) grade 5. FNS was strongly suspected based on the patient's clinical course and magnetic resonance imaging findings, and the patient underwent surgical decompression of the internal auditory canal (IAC) to improve facial nerve function 9 weeks after onset. CFN-EMG responses suddenly improved after removing the posterior wall of the IAC and incising its dura matter. Since the patient's facial nerve paresis improved to HB grade 2 after surgery, CFN-EMGs could detect the moment of facial nerve decompression. This would be the first report to show that CFN-EMGs applied in decompression surgery for FNS could detect the effects of decompression during surgery in real-time. Thus, CFN-EMGs may be an effective monitoring method in decompression surgery for FNS.
面神经功能改善是面神经鞘瘤（FNS）手术中一个具有挑战性的目标。听神经瘤手术中会进行术中面神经诱发肌电图（CFN-EMGs）的连续监测，以保留面神经功能。CFN-EMGs被应用于重度面瘫的FNS减压手术中。一名39岁女性突发眩晕、左耳听力障碍以及House-Brackmann（HB）5级重度左侧面瘫。根据患者的临床病程和磁共振成像结果，强烈怀疑为FNS，患者在发病9周后接受了内耳道（IAC）手术减压以改善面神经功能。切除IAC后壁并切开其硬脑膜后，CFN-EMG反应突然改善。由于患者术后面神经麻痹改善至HB 2级，CFN-EMGs能够检测到面神经减压的时刻。这将是首份表明CFN-EMGs应用于FNS减压手术可在术中实时检测减压效果的报告。因此，CFN-EMGs可能是FNS减压手术中的一种有效监测方法。
