Department of Orthopedic Surgery, Spinal Injuries Center, Iizuka, Japan.
J Neurosurg Spine. 2013 Sep;19(3):288-92. doi: 10.3171/2013.5.SPINE12933. Epub 2013 Jul 12.
The goal of this prospective study was to investigate somatosensory evoked potentials (SSEPs) during dynamic motion of the cervical spine and to evaluate the efficacy of analyzing dynamic SSEPs for predicting dynamic effects on the spinal cord in patients with cervical spondylotic myelopathy (CSM).
In total, 40 human subjects (20 CSM patients and 20 healthy volunteers as a control group) were examined prospectively using dynamic SSEPs with median nerve stimulation. The CSM patients showed cervical myelopathy due to cervical cord compression at the C4-5 segment. The SSEPs were examined with the cervical spine in a neutral position and at a 20° extension for 10 and 20 minutes. Changes in the N20 latency and amplitude were determined and analyzed. The authors defined the changes in the N20 latency and N20 amplitude between the neutral and extension positions of the cervical spine as percent latency and amplitude, respectively.
In the CSM patients, SSEPs tended to deteriorate after cervical spine extension, and a statistically significant deterioration of the N20 amplitude after the extension was observed. Moreover, the percent latency and amplitude progressively increased during cervical spine extension in these patients. In the healthy controls, SSEPs tended to deteriorate with cervical spine extension, but these changes did not result in statistically significant differences. Moreover, in this group the percent latency and amplitude were almost identical during the extension. When the CSM patients and the healthy controls were compared, a significant difference in the percent amplitude was observed between the 2 groups during the cervical spine extension.
This study suggests the potential of dynamic SSEPs as a useful neurophysiological technique to detect the effect of dynamic factors on the pathogenesis of CSM.
本前瞻性研究旨在探讨颈椎动态运动过程中体感诱发电位（SSEP）的变化，并评估分析动态 SSEP 预测颈椎脊髓病（CSM）患者脊髓动态效应的效果。
共对 40 名受试者（20 名 CSM 患者和 20 名健康志愿者作为对照组）进行前瞻性研究，使用正中神经刺激进行动态 SSEP 检查。CSM 患者因 C4-5 节段脊髓受压而出现颈椎脊髓病。SSEP 检查时，颈椎处于中立位和 20°伸展位 10 分钟和 20 分钟。确定和分析 N20 潜伏期和振幅的变化。作者将颈椎中立位和伸展位之间 N20 潜伏期和 N20 振幅的变化定义为潜伏期和振幅的百分比。
CSM 患者 SSEP 在颈椎伸展后趋于恶化，且伸展后 N20 振幅明显恶化。此外，在这些患者中，颈椎伸展过程中潜伏期和振幅的百分比逐渐增加。在健康对照组中，SSEP 在颈椎伸展后也有恶化趋势，但这些变化没有统计学意义。此外，在该组中，伸展过程中潜伏期和振幅的百分比几乎相同。当 CSM 患者和健康对照组进行比较时，在颈椎伸展期间，两组之间的振幅百分比存在显著差异。
本研究表明，动态 SSEP 作为一种有用的神经生理学技术，具有检测动态因素对 CSM 发病机制影响的潜力。
