中文摘要：

目的：探讨体感诱发电位（somatosensory evoked potentials,SEP）对强直性脊柱炎（ankylosing spondylitis,AS）胸腰椎后凸畸形患者经椎弓根椎体截骨术（pedicle subtraction osteotomy,PSO）中体位性臂丛神经损伤的监测作用。方法：选取2013年10月-2014年6月行单节段PSO治疗并有完整术中SEP监测数据及术前、术后临床资料的AS胸腰椎后凸畸形患者28例,其中男27例,女1例。术中均行双上肢正中神经SEP监测,SEP阳性改变标准为波幅降低超过50%和/或潜伏期延长超过10%。结果：PSO术中闭合截骨面复位后,上肢正中神经SEP监测及时发现了3例体位性单侧臂丛神经损伤,SEP波幅降低分别为100%、65%及90%。经体位垫调整后5min,2例SEP波幅降低分别为100%及65%的患者上肢正中神经SEP恢复正常,术后未出现臂丛神经损伤症状;SEP波幅降低90%的患者虽经体位调节,SEP波幅稍有好转,但仍降低70%,术后出现单侧上肢疼痛、乏力的臂丛神经损伤症状,经康复训练及药物治疗后3个月神经功能完全恢复。术中无手术操作引起的神经系统并发症。结论：术中双上肢正中神经SEP监测能及时发现AS胸腰椎后凸畸形PSO术中体位性臂丛神经损伤,经及时处理能有效减轻臂丛神经损伤程度。

英文摘要：

Objectives：To investigate somatosensory evoked potentials（SEP） in monitoring the postural brachial plexus injury in ankylosing spondylitis（AS） patients with thoracolumbar kyphosis following pedicle subtraction osteotomy（PSO）.Methods：From October 2013 to June 2014,28 AS patients with thoracolumbar kyphosis and complete SEP data and clinical data undergoing one-level PSO were included in this study.There were 27 males and 1 female.Medium nerve SEP were recorded in all patients.The positive change criteria of the SEP were as follows：the amplitude decreased exceeding 50% to the baseline,and/or the latency delayed exceeding 10% to the baseline.Results：Three patients developing postural brachial plexus injury during surgery were detected by SEP.The amplitude decreased by 100%,65% and 90% to the baseline respectively.After adjusting the position,2 patients（the amplitude decreased by 100% and 65%） with the signals of SEP recovered,without the clinical symptom of postural brachial plexus injury after surgery.The patient with SEP amplitude decreased by 90% remained abnormal,and postural brachial plexus injury occurred after surgery.After rehabilitation and medication,the neurological function returned to normal 3 months.Conclusions：The postural brachial plexus injury in AS patients with thoracolumbar kyphosis following PSO can be detected by the medium nerve SEP in time.And the medium nerve SEP will decrease the degree of postural brachial plexus injury in AS patients with thoracolumbar kyphosis undergoing PSO if proper measures are adopted timely.