Iwamoto H, Matsuda H, Noriage A, Yamano Y
Department of Orthopaedic Surgery, Osaka City University Medical School, Osaka, Japan.
Spine (Phila Pa 1976). 1997 Nov 15;22(22):2636-40. doi: 10.1097/00007632-199711150-00011.
A model of chronic cauda equina compression with conductive stress was studied electrophysiologically.
To analyze the pathophysiology arising from chronic compression electrophysiologically.
This rat model of cauda equina compression that is chronic, not acute, has been reported elsewhere.
A stainless steel wire and plate were fastened to the spine at L5 of 8 rats 3 weeks old. One year later, the ascending and descending nerve action potentials were recorded and the conduction velocities (CVs) were measured. Electrophysiologic changes after high-frequency stimulation (HFS) were observed.
The waveform of the ascending cauda equina action potential at the cauda equina had three peaks, and that at the conus medullaris had a peak followed by a broad wave. The waveform of the descending nerve action potential had two peaks. The mean ascending and descending CVs of the treated rats were slower (P < 0.001) than those of the control rats. In the control rats, the mean CV and mean amplitude after HFS decreased slightly and returned to normal within 30 seconds, and the waveform was unchanged. In treated rats, the mean CV decreased after HFS but returned to normal within 10 minutes. The mean amplitude decreased after HFS and did not return to normal within 10 minutes. The waveform was unchanged.
Because the differences between treated and control rats in amplitude (and CVs) were greater before HFS than after HFS, we concluded that treated rats had disturbance of the blood flow in vessels around the nerves of the cauda equina with histologic damage. In human patients, such disturbance may be one cause of intermittent claudication.
用电生理学方法研究了一种伴有传导性应力的慢性马尾神经压迫模型。
从电生理学角度分析慢性压迫引起的病理生理学变化。
这种慢性而非急性的马尾神经压迫大鼠模型已在其他地方报道过。
将一根不锈钢丝和一块钢板固定在8只3周龄大鼠的L5脊柱上。一年后，记录上下行神经动作电位并测量传导速度（CV）。观察高频刺激（HFS）后的电生理变化。
马尾神经处上行马尾神经动作电位的波形有三个峰，脊髓圆锥处的有一个峰后接一个宽波。下行神经动作电位的波形有两个峰。治疗组大鼠的平均上下行CV比对照组大鼠慢（P < 0.001）。在对照组大鼠中，HFS后平均CV和平均振幅略有下降，并在30秒内恢复正常，波形未改变。在治疗组大鼠中，HFS后平均CV下降，但在10分钟内恢复正常。平均振幅在HFS后下降，且在10分钟内未恢复正常。波形未改变。
由于治疗组和对照组大鼠在振幅（和CV）上的差异在HFS前比HFS后更大，我们得出结论，治疗组大鼠马尾神经周围血管的血流存在紊乱并伴有组织学损伤。在人类患者中，这种紊乱可能是间歇性跛行的一个原因。
