磁刺激运动诱发电位在腰骶神经根病应用研究

作者采用磁刺激腰骶部运动诱发电位（ＭＥＰ）和磁刺激窝Ｆ波相结合的方法测定运动神经根传导时间（ＭＲＣＴ）．随机抽查５０名正常受试者在胫骨前肌（ＴＡ）和比目鱼肌（ＳＯＬ）记录出可靠的运动神经传导时间（ＭＮＣＴ）和ＭＲＣＴ；同样方法记录和观察４０例手术证实单例Ｌ５或Ｓ１神经根受压患者ＭＮＣＴ和ＭＲＣＴ的改变，同时进行节段性皮神经刺激皮层体感诱发电位（ＳＥＰ）对比．结果显示：病人组ＭＮＣＴ与正常组相比无显著性差异，而ＭＲＣＴ则有显著性差异．异常率为８５％，其明显高于ＳＥＰ的异常率４５％．因此，无痛无创的磁刺激ＭＥＰ对腰骶神经根病有很大的使用价值，而且磁刺激优于电刺激．

ClinicalStudyofMotorEvokedPotentialsbyMagneticStimulationinLumbosacralRadiculopathy

Sincemagneticstimulationisanewpainlessandnoninvasivetechniqueinelectrophysi-ology,ithasbeenusedintheassessmentofthelumbosacralrootfunction.Howeverthemethodtocal-culatemotorrootconductiontime(MRCT)usedinthepastwastocombinetheelectricalstimulationelicitedFwavewiththemagneticstimulationelicitedmotorevokedpotentials(MEP).Inthisstudy,MRCTwascalculatedbycombiningthemagneticstimlationelicitedMEPinlumbosacralregionwiththesamestimulationelicitedFwaveinthepoplitealfossa.TheaimofthisstudywastoshowthatMRCTcanbeobtainedbyusingmagneticstimulationaloneandthismethodisvaluableinthediagnosisforlum-bosacralradiculopathy.Fiftynormalsubjectsand40patientssuferingfromL5orS1radiculopathiesduetodiscprotrusionwerestudied.FwaveandMwavewererecordedfromthetibialisanterior(TA)andthesoleus(SOL)musclesbystimulatingcommonperonealnerveandtibialnerveoverthepoplitealfos-sawithbothelectricalandmagneticstimulation.Stimlationoverthevertebralcolumnwasobtainedus-ingaDantecMag2stimulatortostimulatethelumbosacralroots.Motornerveconductiontime(MNCT)andMRCTwererecordedfromtheTAandtheSOL.Meanwhile.corticalsomatosensorye-vokedpotentials(SEP)wererecordedbysegmentalcutaneousnervestimulationforcomparison.TheresultshowedthatnodiferencewasseeninMNCTinalthepatientsbutMRCTwasmarkedlypro-longedin85%ofthepatients,whichwashigherthantheprolongationofSEPin45%ofthepatients.ItwasconcludedthatMRCTcouldbecalculatedreliablybyusingmagneticstimulationaloneandmag-neticstimulationofMEPwasausefultechniquefornoninvasivediagnosisoflumbosacralradicu-lopathies.