Segura Martín J, Talarico María E, Noel Mariano A
*Clinical Neurophysiology Unit, Department of Neurology, Hospital Nacional de Pediatría "Dr. Juan P. Garrahan," Buenos Aires, Argentina; and †Department of Spinal Surgery, Hospital Nacional de Pediatría "Dr. Juan P. Garrahan," Buenos Aires, Argentina.
J Clin Neurophysiol. 2017 Jan;34(1):38-48. doi: 10.1097/WNP.0000000000000323.
This is a pilot study to compare changes in the amplitude, area below the curve, number of phases, duration, and latency of the intraoperative transcranial motor evoked potentials (TcMEP) for early detection of impending spinal cord injury. An empirical ratio calculated by a combination of the above-mentioned parameters was also assessed.
Intraoperative TcMEP recordings from five patients presenting with neuromuscular kyphoscoliosis, idiopathic scoliosis, achondroplasia and lumbar kyphosis, congenital kyphosis, and achondroplasia with cervical instability were reviewed. Anesthesia was sustained with propofol or sevoflurane plus remifentanil, no muscle relaxants were used after intubation. The TcMEPs to multipulse electrical stimulation were recorded from upper-limb and lower-limb muscles. To be worthy of analyses, changes should include TcMEP disappearance or amplitude decrease >-65% during surgical/force maneuverings.
Transient TcMEP changes related to surgical/force maneuvering were observed in all five patients consisting of a decrease in the empirical ratio value (>-95%), followed in magnitude by a drop in the area below the curve, amplitude (>-80%), duration, and number of phases, whereas latency increased. Changes returned to baseline when maneuverings were reverted. No hemodynamic/anesthetic factors were present during these events. After surgeries, no new neurological deficits were detected.
An empirical ratio accounting for all TcMEP parameters seems to drop more than the amplitude during an intraoperative event. As few cases were analyzed, further studies in larger series of patients will be necessary to assess empirical ratio sensitivity/specificity and to determine whether this may be a useful monitoring warning criterion not leading to unnecessary interference with surgical treatment.
这是一项前瞻性研究，旨在比较术中经颅运动诱发电位（TcMEP）的波幅、曲线下面积、相位数量、持续时间和潜伏期的变化，以早期检测即将发生的脊髓损伤。还评估了通过上述参数组合计算得出的经验比值。
回顾了5例患有神经肌肉性脊柱后凸、特发性脊柱侧凸、软骨发育不全和腰椎后凸、先天性脊柱后凸以及伴有颈椎不稳的软骨发育不全患者的术中TcMEP记录。采用丙泊酚或七氟醚加瑞芬太尼维持麻醉，插管后未使用肌肉松弛剂。记录上肢和下肢肌肉对多脉冲电刺激的TcMEP。为了值得分析，变化应包括手术/用力操作期间TcMEP消失或波幅下降>-65%。
在所有5例患者中均观察到与手术/用力操作相关的短暂TcMEP变化，包括经验比值下降（>-95%），其次是曲线下面积、波幅（>-80%）、持续时间和相位数量下降，而潜伏期增加。操作恢复后，变化恢复至基线。这些事件期间未出现血流动力学/麻醉因素。手术后，未发现新的神经功能缺损。
考虑所有TcMEP参数的经验比值在术中事件期间似乎比波幅下降得更多。由于分析的病例较少，有必要对更多患者进行进一步研究，以评估经验比值的敏感性/特异性，并确定这是否可能是一个有用的监测警告标准，而不会导致对手术治疗的不必要干扰。
