Kakinohana Manabu, Nakamura Seiya, Fuchigami Tatsuya, Sugahara Kazuhiro
Department of Anesthesiology, University of the Ryukyus, Nishihara, Okinawa, Japan.
Eur Spine J. 2007 Jun;16(6):787-93. doi: 10.1007/s00586-006-0165-1. Epub 2006 Jun 28.
In this study, we evaluated the efficacy of transcranial motor-evoked potentials (tc-MEPs), compared with segmental spinal cord-evoked potentials (SCEPs), for detecting spinal cord ischemia (SCI) and assessed the relationship between neurological outcome and tc-MEPs or SCEPs in the rat aortic occlusion model. In the rats, SCI was induced by aortic occlusion for 10 min with a balloon catheter. At first, tc-MEPs (Group A: n = 6) or segmental SCEPs (Group B: n = 6) was recorded during SCI. Second, in using the quantal bioassay for the relationship between an interval of aortic occlusion and the probability of positive response in tc-MEPs or segmental SCEPs, the P50(MEP) and P50(SCEP) which represent the interval of aortic occlusion associated with 50% probability of assessment of ischemic spinal cord dysfunction by tc-MEP and SCEP were analyzed. The amplitude of tc-MEPs decreased significantly at 30 s and disappeared completely at 2 min after aortic occlusion. In Group B, it took about 6 min after aortic occlusion to diminish SCEP signal amplitude by approximately 50%. P50(MEP) obtained in the quantal analysis was 0.3 +/- 0.1 min. P50(SCEP) was calculated as 6.2 +/- 0.5 min that was significantly (P < 0.01) longer than P50(MEP). Our data indicated that tc-MEP monitoring could detect the onset of SCI so rapidly in comparison with segmental SCEP monitoring, which could provide therapeutic windows in a surgical approach that includes spinal cord protection.
在本研究中，我们评估了经颅运动诱发电位（tc-MEPs）与节段性脊髓诱发电位（SCEPs）相比，在检测脊髓缺血（SCI）方面的有效性，并在大鼠主动脉闭塞模型中评估了神经功能结局与tc-MEPs或SCEPs之间的关系。在大鼠中，使用球囊导管将主动脉闭塞10分钟以诱导脊髓缺血。首先，在脊髓缺血期间记录tc-MEPs（A组：n = 6）或节段性SCEPs（B组：n = 6）。其次，在使用定量生物测定法研究主动脉闭塞间隔与tc-MEPs或节段性SCEPs阳性反应概率之间的关系时，分析了代表与通过tc-MEP和SCEP评估缺血性脊髓功能障碍50%概率相关的主动脉闭塞间隔的P50(MEP)和P50(SCEP)。主动脉闭塞后30秒，tc-MEPs的振幅显著下降，2分钟时完全消失。在B组中，主动脉闭塞后约6分钟，SCEP信号振幅降低约50%。定量分析中获得的P50(MEP)为0.3±0.1分钟。计算得出P50(SCEP)为6.2±0.5分钟，明显（P < 0.01）长于P50(MEP)。我们的数据表明，与节段性SCEP监测相比，tc-MEP监测能够如此快速地检测到脊髓缺血的发作，这可以在包括脊髓保护的手术方法中提供治疗窗口。
