摘要目的:探讨触发肌电图(tEMG)对儿童脊髓拴系松解术中神经功能的评估价值。方法:回顾性分析2020年1月至2022年8月上海交通大学医学院附属上海儿童医学中心神经外科收治的85例术中行tEMG监测的脊髓拴系综合征患儿的临床资料。术前48例患儿存在神经功能障碍，所有患儿均行脊髓拴系松解术，记录术前病变部位神经根引出靶向肌肉的复合肌肉动作电位(CMAP)的tEMG刺激阈值及波幅；术后即刻再次对神经根进行监测，比较术前、术后即刻tEMG阈值的差异；术后即刻以术前tEMG的阈值刺激神经根，比较术前、术后即刻引出CMAP波幅的差异(每例患者的tEMG阈值及CMAP波幅均为刺激其病变部位双侧神经根后获得的平均值)。评估患儿术后神经功能的改善情况。结果:85例患儿的手术均顺利完成，术后经病理学证实为脊髓脂肪瘤43例，脂肪脊髓脊膜膨出8例，脊髓脊膜膨出6例，继发性脊髓拴系综合征28例。术后均无脑脊液漏、切口感染等并发症发生。术后70.8%(34/48)的患儿神经功能障碍改善。与术前相比，患儿病变部位神经根的tEMG阈值[ M( Q1， Q3)]在术后即刻明显下降，差异具有统计学意义[术前：3.40(1.60，5.00)mA，术后即刻：2.10(1.50，3.50)mA， Z＝5.89， P<0.001]；其中术后即刻31例脊髓脂肪瘤、8例脂肪脊髓脊膜膨出、5例脊髓脊膜膨出、17例继发性脊髓拴系综合征患儿的tEMG阈值均较术前明显下降，差异均具有统计学意义(均 P<0.05)。使用术前的tEMG阈值刺激术后即刻的神经根，术后即刻患儿的CMAP波幅[ M( Q1， Q3)]较术前明显升高，差异具有统计学意义[术前：8.40(5.00，17.50)μV，术后即刻：17.50(8.15，26.78)μV， Z＝－6.20， P<0.001]；其中术后即刻36例脊髓脂肪瘤、6例脊髓脊膜膨出、18例继发性脊髓拴系综合征患儿的CMAP波幅较术前明显升高，差异均具有统计学意义(均 P<0.05)，而8例脂肪脊髓脊膜膨出患儿术前、术后即刻CMAP的波幅改变不明显( P＝0.192)。 结论:术中tEMG不仅能监测保护患儿的神经功能，还可以提示神经功能改善情况，具有较好的应用价值。

abstractsObjective:To evaluate the application value of triggered electromyography (tEMG) in the assessment of neurological function during spinal cord tethering release surgery in children.Methods:A retrospective analysis was conducted on the clinical data of 85 children with spinal cord tethering syndrome who were admitted to the Department of Neurosurgery, Shanghai Children′s Medical Center, School of Medicine, Shanghai Jiao Tong University from January 2020 to August 2022 and underwent intraoperative tEMG monitoring. A total of 48 children had neurological dysfunction preoperatively. All 85 patients were subjected to spinal cord tethering release surgery. The stimulation threshold and amplitude of the tEMG eliciting compound muscle action potential (CMAP) in the target muscle, which induced by nerve roots at the lesion site before surgery was documented. The nerve root was tested again immediately after surgery and the difference in tEMG thresholds before surgery and immediately after surgery was analyzed. The preoperative tEMG threshold was used to stimulate the nerve roots immediately after surgery, the difference in CMAP amplitude before and immediately after surgery was analyzed(the tEMG threshold and CMAP amplitude of each patient were the average values obtained when stimulating bilateral nerve roots at the lesion site), and improvement of neurological function in children after surgery was evaluated.Results:The surgeries were successfully completed in all 85 children. Postoperative pathology confirmed 43 cases of spinal lipoma, 8 cases of lipomyomeningocele, 6 cases of myelomeningocele, and 28 cases of secondary tethered cord syndrome. There were no postoperative complications such as cerebrospinal fluid leakage and incision infection. Neurological dysfunction improved in 70.8%(34/48) of the children after surgery. Compared with preoperatively, the tEMG threshold [ M( Q1, Q3)] of the nerve root in the lesion site of the child decreased significantly immediately after surgery, and the difference was statistically significant [preoperative: 3.40 (1.60, 5.00)mA, immediately after surgery: 2.10 (1.50, 3.50)mA, Z=5.89, P<0.001)]. In 31 cases of spinal lipoma, 8 cases of lipomyelomeningocele, 5 cases of myelomeningocele and 17 cases of secondary tethered cord syndrome, the tEMG thresholds in the immediate postoperative period were significantly lower than those before surgery, and the differences were statistically significant (all P<0.05). With the tEMG threshold before tethered cord release surgery was being used to stimulate the nerve roots immediately after surgery, the CMAP amplitude[ M( Q1, Q3)] of the nerve roots elicited immediately after surgery increased significantly compared with before surgery, and the difference was statistically significant [preoperative: 8.40 (5.00, 17.50)μV, immediately after surgery: 17.50 (8.15, 26.78)μV, Z=-6.20, P<0.001]. Among them, the CMAP amplitude of 36 children with spinal lipoma, 6 children with myelomeningocele, and 18 children with secondary tethered cord syndrome increased significantly immediately after surgery compared with that before surgery, and the differences were all statistically significant (all P<0.05), while the amplitude of CMAP did not change significantly before and immediately after surgery in 8 children with lipomyelomeningocele( P=0.192). Conclusions:Intraoperative tEMG can not only help monitor and protect the neurological function of children, but also indicate the improvement of neurological function. It has good application value.