Kearse L A, Lopez-Bresnahan M, McPeck K, Tambe V
Department of Anesthesia, Massachusetts General Hospital, Boston 02114.
J Clin Anesth. 1993 Sep-Oct;5(5):392-8. doi: 10.1016/0952-8180(93)90103-l.
To estimate the sensitivity and specificity of somatosensory evoked potentials (SSEPs) for predicting new postoperative motor neurologic deficits during intramedullary spinal cord surgery; to establish whether SSEPs more accurately predicted postoperative deficits in position and vibration sense than in strength.
Prospective open and retrospective study.
University-affiliated hospital.
20 patients with intramedullary spinal cord tumors scheduled for surgery with intraoperative SSEPs.
Median, ulnar, and tibial nerve cortical and subcortical SSEPs were recorded continuously.
Conventional intraoperative SSEP criteria considered indicative of neurologic injury were modified and defined as either the complete and permanent loss of the SSEP or the simultaneous amplitude reduction of 50% or greater in the nearest recording electrode rostral to the surgical site and 0.5 millisecond increase in the central latency. Our definition required confirmation of both amplitude and latency changes on a repeated average. All patients had 1 or more SSEPs, which were reproducible and sufficiently stable for analysis throughout the operation. Six patients developed new postoperative neurologic deficits. One had new motor deficits in an extremity from which no baseline SSEPs could be elicited. In each of the other 5 patients, significant SSEP changes preceded the postoperative motor deficits in the extremity or extremities monitored. In no patient without a new postoperative motor deficit was there a significant change in the SSEP. In only 2 of these 5 patients was there a documented postoperative loss or diminution in vibration or position sense.
Intraoperative SSEP changes during intramedullary spinal cord surgery are a sensitive predictor of new postoperative motor deficits, but such changes may not correlate reliably with postoperative deficits in position or vibration sense. In this setting SSEP monitoring serves primarily to reassure the operating team that, when the SSEPs remain constant, the surgery has not caused additional injury.
评估体感诱发电位（SSEPs）在预测脊髓髓内手术术后新发运动神经功能缺损方面的敏感性和特异性；确定SSEPs在预测术后位置觉和振动觉缺损方面是否比肌力缺损更准确。
前瞻性开放性和回顾性研究。
大学附属医院。
20例计划行脊髓髓内肿瘤手术且术中监测SSEPs的患者。
连续记录正中神经、尺神经和胫神经的皮质及皮质下SSEPs。
对传统术中认为提示神经损伤的SSEP标准进行修改，定义为SSEP完全且永久性消失，或手术部位近端最近记录电极处SSEP波幅同时降低50%或更多，且中枢潜伏期增加0.5毫秒。我们的定义要求在重复平均时确认波幅和潜伏期的变化。所有患者均有1个或更多可重复且在整个手术过程中足够稳定用于分析的SSEPs。6例患者术后出现新发神经功能缺损。1例患者肢体出现新发运动功能缺损，但术前无法引出该肢体的基线SSEPs。在其他5例患者中，每例患者监测肢体的术后运动功能缺损之前均出现了显著的SSEP变化。没有术后新发运动功能缺损的患者，其SSEP均无显著变化。在这5例患者中，只有2例记录到术后振动觉或位置觉丧失或减退。
脊髓髓内手术术中SSEP变化是术后新发运动功能缺损的敏感预测指标，但这些变化可能与术后位置觉或振动觉缺损无可靠相关性。在此情况下，SSEP监测主要是让手术团队放心，即当SSEPs保持恒定时，手术未造成额外损伤。
