腰骶神经根减压术中皮节体感诱发电位监测及其相关因素分析

Analysis of relative factors of lumbosacral nerve root decompression in monitoring dermato- mal somatosensory evoked potentials during operationg

目的：探讨腰骶神经根减压手术中皮节体感诱发电位（DSEP）监测的临床意义。方法：对46例经查体、腰椎MRI及DSEP检查证实存在单侧腰骶神经根（腰5或骶1神经根）压迫的患者，术前按照40岁为节点进行年龄分层（大龄组和低龄组）、病程分层以3个月为节点（慢程组和短程组）、失血量分层以200ml作为节点（大量失血组和少量失血组）；在术中进行受累节段双侧神经根DSEP监测，观察并记录不同时间节点（麻醉后、减压前及减压后）的P40波潜伏期、波幅的数据，计算减压前后P40波幅的改善率，分别以0．5、0为节点将其分层（明显改善组、不明显改善组和无改善组），比较上述不同因素分层后的相关指标。结果：大龄组疼痛视觉模拟评分（VAS）与Oswestry功能障碍（ODD改善率之间，低龄组P40波幅改善率与ODI改善率、VAS与ODI改善率之间，P40波幅变化率、VAS改善率在不同病程组，病程、VAS改善率在不同P40波幅改善率组差异有显著意义（P〈0．05）。结论：在应用DSEP分析腰骶神经根减压效果时，在不同患者相关因素下的P40波幅改善率具有重要的临床价值和意义。

Objective：To discuss the clinical value of dermatomal somatosensory evoked potentials （DSEP） during operation in monitoring lumbosacral nerve root decompression. Methods： Forty-six cases diagnosised unilateral lumbosacral nerve root （L5 or S1） by clinical, lumbra magnetic resonance imaging （MRI）and DSEP examination were respectively layered for the old group and young group, chronic course group and short rouse group, and massive blood loss group and small blood loss group by patients＇ age （point = 40 years）, course （point = 3 months）, and missing blood volume （during decompression, point 200 ml）. All patients were monitored during operation to with their DSEP. L5 or S1 nerve roots of both sides examined and P40 latency and amplitude data acquired. Then P40-amplitude improvement rates were layered for significant improved group,indistinctive improved group and unimproved group（point= 0 and 0. 5）. Above-mentioned indexs were compared. Results： There were significant difference between visual analog seale（VAS） and ODI improvement rates in the old group,P40 amplitude and ODI improve- ment rates/VAS and ODI improvement rates in the young group; P40 amplitude and VAS improvement rates in different course group, course and VAS improvement rates in different P40 amplitude improve- ment rates group of involved nerve roots were significantly different（P〈0.05）. Conclusion：The improve- ment rates of P40 amplitude in different relative factors can play an important clinical role when DSEP is reflected decompressive effect of lumbosacral nerve roots.