Israel Jacqueline S, Kempton Steve J, Afifi Ahmed M
Ann Plast Surg. 2018 Jul;81(1):71-74. doi: 10.1097/SAP.0000000000001446.
Migraine surgery and onabotulinumtoxinA injections aim to deactivate neurovascular trigger points implicated in chronic headaches. The greater occipital nerve (GON) is a common trigger point. The depth of this nerve has not been previously described. The purpose of this study was to report the intraoperative location, including depth, of the GON in human subjects undergoing migraine surgery.
We reviewed records of patients who underwent GON decompression by a single surgeon. Intraoperative measurement of the GON location lateral to midline, inferior to the occipital protuberance, and deep to the skin was collected for 2 previously described positions: where GON (a) enters, "point #2," and (b) exits, "point #3," the semispinalis muscle as it travels from deep to superficial (Plast Reconstr Surg. 2010;126:1563-1572; Plast Reconstr Surg. 2004;113:693-697).
Thirty-four subjects (60 nerves) were included. The mean depths of the GON were 20 mm (SD, 4) at point no. 3 and 30 mm (SD, 6) at point no. 2. In 26 subjects who underwent bilateral surgery, there was a difference between right and left nerve position lateral to midline at point no. 3 (P = 0.008). Female sex (P = 0.014) and body mass index of 29 kg/m or less (P < 0.001) were associated with a more superficial GON position.
Knowledge of the GON depth (eg, mean of 20 mm where it emerges from the semispinalis muscle) may improve accuracy of procedural treatments for migraines. When performing bilateral interventions, nerve position may differ between sides, particularly with respect to lateral distance from midline. Differences in this study compared with previous anatomic studies may reflect the use of live subjects in a prone position compared with cadaver specimens.
偏头痛手术和注射A型肉毒毒素旨在使与慢性头痛相关的神经血管触发点失活。枕大神经（GON）是常见的触发点。此前尚未描述该神经的深度。本研究的目的是报告接受偏头痛手术的人体受试者中GON在术中的位置，包括深度。
我们回顾了由一位外科医生进行GON减压手术的患者记录。术中测量了GON在中线外侧、枕外隆凸下方以及皮肤深层的位置，记录了之前描述的两个位置：GON（a）进入半棘肌处，即“点2”，以及（b）穿出半棘肌处，即“点3”（《整形再造外科杂志》。2010年；126:1563 - 1572；《整形再造外科杂志》。2004年；113:693 - 697）。
纳入了34名受试者（60条神经）。GON在点3的平均深度为20毫米（标准差，4），在点2的平均深度为30毫米（标准差，6）。在26名接受双侧手术的受试者中，点3处右侧和左侧神经在中线外侧的位置存在差异（P = 0.008）。女性（P = 0.014）和体重指数为29千克/平方米或更低（P < 0.001）与GON位置更浅表有关。
了解GON的深度（例如，从半棘肌穿出时的平均深度为20毫米）可能提高偏头痛手术治疗的准确性。进行双侧干预时，神经位置可能存在侧别差异，尤其是相对于中线的外侧距离。与之前的解剖学研究相比，本研究中的差异可能反映了与尸体标本相比，使用俯卧位活体受试者的情况。
