Imajo Yasuaki, Kanchiku Tsukasa, Suzuki Hidenori, Funaba Masahiro, Nishida Norihiro, Fujimoto Kazuhiro, Taguchi Toshihiko
Department of Orthopaedic Surgery, Yamaguchi University Graduate School of Medicine, Ube, Japan.
J Clin Neurophysiol. 2017 Mar;34(2):132-138. doi: 10.1097/WNP.0000000000000351.
Lumbar spinal stenosis typically presents with neurogenic intermittent claudication. The aim of this study was to investigate cauda equina conduction time (CECT) in patients with neurogenic intermittent claudication caused by lumbar spinal stenosis and its relationship with age and body height in normal subjects.
The study included 172 normal subjects (group C) (mean age 44.1 ± 16.6 years; mean height 163.7 ± 8.9 cm). Forty-seven patients (group L) (mean age 71.3 ± 8.7 years; mean height 158.8 ± 11.2 cm) underwent surgery because of neurogenic intermittent claudication in cauda equina type of lumbar spinal stenosis. Motor-evoked potentials from the abductor hallucis were recorded. Magnetic stimulation was delivered at the S1 spinous process. Compound muscle action potentials (CMAPs) and F-waves were also recorded after supramaximal electric stimulation of tibial nerves. The peripheral motor conduction time (PMCT) was calculated from the latencies of CMAPs and F-waves as follows: (CMAPs + F-waves - 1)/2. The CECT was calculated by subtracting the onset latency of the motor-evoked potentials from PMCT.
The mean values for F-wave latencies, motor-evoked potential latencies, and CECT were 44.5 ± 3.3, 20.6 ± 1.8, and 3.4 ± 0.8 milliseconds, respectively. F-wave and motor-evoked potential latencies showed significant positive linear correlations with age and body height. However, no significant correlation was found between CECT and age (P = 0.43) or body height (P = 0.26). Mean CECT was 5.7 ± 1.5 in group L. There was a significant difference between groups C and L (P < 0.05).
The CECT value of normal subjects was 3.4 ± 0.8 milliseconds regardless of age and body height. We suggest that CECT may be a useful factor to consider when evaluating patients with neurogenic intermittent claudication.
腰椎管狭窄症通常表现为神经源性间歇性跛行。本研究旨在探讨腰椎管狭窄症所致神经源性间歇性跛行患者的马尾神经传导时间（CECT），及其与正常受试者年龄和身高的关系。
本研究纳入172名正常受试者（C组）（平均年龄44.1±16.6岁；平均身高163.7±8.9厘米）。47名患者（L组）（平均年龄71.3±8.7岁；平均身高158.8±11.2厘米）因马尾型腰椎管狭窄症导致的神经源性间歇性跛行接受手术。记录拇展肌的运动诱发电位。在S1棘突处进行磁刺激。在对胫神经进行超强电刺激后，还记录复合肌肉动作电位（CMAPs）和F波。外周运动传导时间（PMCT）根据CMAPs和F波的潜伏期计算如下：（CMAPs + F波 - 1）/2。CECT通过从PMCT中减去运动诱发电位的起始潜伏期来计算。
F波潜伏期、运动诱发电位潜伏期和CECT的平均值分别为44.5±3.3、20.6±1.8和3.4±0.8毫秒。F波和运动诱发电位潜伏期与年龄和身高呈显著正线性相关。然而，CECT与年龄（P = 0.43）或身高（P = 0.26）之间未发现显著相关性。L组的平均CECT为5.7±1.5。C组和L组之间存在显著差异（P < 0.05）。
无论年龄和身高如何，正常受试者的CECT值为3.4±0.8毫秒。我们建议，在评估神经源性间歇性跛行患者时，CECT可能是一个需要考虑的有用因素。
