Kim Dong Gun, Choi Young Doo, Jin Seung Hyun, Kim Chi Heon, Lee Kwang Woo, Park Kyung Seok, Chung Chun Kee, Kim Sung Min
Department of Neurology, Myung Diagnostic Radiology Clinic, Seoul, Korea.
Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
J Clin Neurol. 2017 Jan;13(1):38-46. doi: 10.3988/jcn.2017.13.1.38. Epub 2016 Oct 7.
We studied the clinical significance of amplitude-reduction and disappearance alarm criteria for transcranial electric muscle motor-evoked potentials (MEPs) during cervical spinal surgery according to different lesion locations [intramedullary (IM) vs. nonintramedullary (NIM)] by evaluating the long-term postoperative motor status.
In total, 723 patients were retrospectively dichotomized into the IM and NIM groups. Each limb was analyzed respectively. One hundred and sixteen limbs from 30 patients with IM tumors and 2,761 limbs from 693 patients without IM tumors were enrolled. Postoperative motor deficits were assessed up to 6 months after surgery.
At the end of surgery, 61 limbs (2.2%) in the NIM group and 14 limbs (12.1%) in the IM group showed MEP amplitudes that had decreased to below 50% of baseline, with 13 of the NIM limbs (21.3%) and 2 of the IM limbs (14.3%) showing MEP disappearance. Thirteen NIM limbs (0.5%) and 5 IM limbs (4.3%) showed postoperative motor deficits. The criterion for disappearance showed a lower sensitivity for the immediate motor deficit than did the criterion for amplitude decrement in both the IM and NIM groups. However, the disappearance criterion showed the same sensitivity as the 70%-decrement criterion in IM (100%) and NIM (83%) surgeries for the motor deficit at 6 months after surgery. Moreover, it has the highest specificity for the motor deficits among diverse alarm criteria, from 24 hours to 6 months after surgery, in both the IM and NIM groups.
The MEP disappearance alarm criterion had a high specificity in predicting the long-term prognosis after cervical spinal surgery. However, because it can have a low sensitivity in predicting an immediate postoperative deficit, combining different MEP alarm criteria according to the aim of specific instances of cervical spinal surgery is likely to be useful in practical intraoperative monitoring.
我们通过评估术后长期运动状态，研究了根据不同病变位置[髓内（IM）与非髓内（NIM）]在颈椎手术期间经颅电刺激肌肉运动诱发电位（MEP）的波幅降低和消失报警标准的临床意义。
总共723例患者被回顾性分为IM组和NIM组。分别对每个肢体进行分析。纳入了30例IM肿瘤患者的116个肢体和693例无IM肿瘤患者的2761个肢体。术后6个月内评估运动功能缺损情况。
手术结束时，NIM组61个肢体（2.2%）和IM组14个肢体（12.1%）的MEP波幅降至基线的50%以下，NIM组13个肢体（21.3%）和IM组2个肢体（14.3%）的MEP消失。13个NIM肢体（0.5%）和5个IM肢体（4.3%）出现术后运动功能缺损。在IM组和NIM组中，消失标准对即时运动功能缺损的敏感性均低于波幅降低标准。然而，在IM组（100%）和NIM组（83%）手术中，消失标准对术后6个月运动功能缺损的敏感性与70%波幅降低标准相同。此外，在IM组和NIM组中，从术后24小时至6个月的不同报警标准中，消失标准对运动功能缺损具有最高的特异性。
MEP消失报警标准在预测颈椎手术后的长期预后方面具有较高的特异性。然而，由于其在预测术后即时缺损方面敏感性较低，根据颈椎手术具体情况的目标结合不同的MEP报警标准可能在实际术中监测中有用。
