脊髓与马尾的运动传导

Motor conduction in spinal cord and cauda equina

目的：用下行运动通路的经皮直接电刺激法测定脊髓与马尾运动传导时间和运动传导速度，并与马尾传导的间接测定法（F波─S1刺激法）相比较。方法：用窄高压方波电脉冲刺激上、下肢皮层运动区及T1、T12、S1棘突的相应皮肤，在大鱼际肌及伸趾短肌记录相应的运动诱发电位（MEP），测定和计算下行通路各段的运动传导时间（MCT）和运动传导速度（MCV）。结果：上、下肢中枢MCT分别为7．69±0．83ms、14．30±1．32ms，皮层─S1MCT为16．97±1．27ms，脊髓MCT为6．60±1．68ms，脊髓─马尾MCT为9．28±1．38ms，马尾MCT为2．62±0．67ms，脊髓MCV为60．5±14．1m／s，脊髓─马尾MCV为56．6±7．96m／s，马尾MCV为54．8±13．0m／s，后者比间接的F波─S1刺激法（48．0±21．3m／s）快而标准差小。结论：用下行通路的窄脉冲高电压方波经皮刺激法测定脊髓、马尾下行运动传导是一准确且无创无痛的直接电生理方法。

Objectives:To obtain the motor conduction the and the motor conduction velocity of the spical cord and the cauda eqina by direct percutaneous electrical stimulation in the derending motor pathway, and to compare with those by indirect way of F wave-S1 stimulation Methods:Motor evoked potentials(elicited by narrow pulse and high voltage square wave stimulation in the motor cortex of the extremities and in the skin area corresponding to the spinal process of T1, T12 and S1)were recorded in thenar and extensor digitorum brevis. Motor conduction the and motor conduction velocity of the descending pathway were measured and calculated. Results:The cental motor conduction time (CMCT) of the lower and upper extremities was 7.69±0.83 ms,and 14.31 ±1 .32 ms. MCT of the cortex to S1, the spinal cord(T1 to T12),the spinal cord to the cauda equina and Oo the cauda equin was 16.97±1.27ms,6.60±1 .68 ms,9. 28± 1. 38 ms,2. 62±0. 67 ms respectively. The motor conduction velocity(MCV) of the spinal cord, the spinal cord to the cauda equina, and of the cauda equina was 60.50±14.1 m/s,56.67±7.69m/s and 54.80±13.0 m/s respectively.The MCV by direct percutaneous stimulation was haer than those by ,eams of indirect F wave stimulation(48.0±21. 3ms), and its standard dsviation was more less. Conchusions: Measuring the descending motor conduction of the spinal cord and the cauda equina by narrow pulse and high voltage square wave stimulationin in the descending pathway might be an accurate and non-invasive electrophysiological method.