经身高校正后皮节体感诱发电位对腰骶神经根损害的诊断价值

Diagnostic value of dermatomal somatosensory evoked potentials by height calibration in diagnosing lumbosacral nerve root injury

目的:探讨皮节体感诱发电位(DSEP)潜伏期经身高校正后对腰骶神经根受损的诊断价值。方法:对50例正常人进行DSEP检测,先测定身高,再分别测定双下肢L4、L5、S1神经根P40峰潜伏期,用每一例正常人L4、L5、S1神经根的P40峰潜伏期除以本人身高,再经统计得出50例正常人经身高校正后L4、L5、S1神经根的P40峰潜伏期值。对96例临床诊断并经手术证实的有单侧下肢放射痛症状的腰椎间盘突出症(LDH)患者术前进行DSEP检测,分别测定健侧与患侧L4、L5、S1神经根。DSEP异常的诊断标准:P40波消失,P40峰潜伏期延长超过正常均数2.5倍标准差,P40峰潜伏期侧间差超过健侧均数2.5倍标准差。结果:50例正常人在身高校正前L4、L5、S1神经根的P40峰潜伏期分别为37.34±2.18ms、44.99±2.91ms和40.99±2.64ms,经身高校正后分别为身高×(22.88±1.08)ms、身高×(27.55±1.34)ms和身高×(25.06±1.11)ms。96例LDH患者中,P40峰潜伏期不经身高校正有86例DSEP异常,诊断符合率为89.6%;经身高校正后则有92例DSEP异常,其诊断符合率为95.8%,与身高校正前比较有显著性差异(P<0.05)。结论:DSEP能反映腰骶神经根功能状态,经身高校正后DSEP诊断符合率得到提高,具有重要的临床应用价值。

Objective：To discuss the diagnosing and applying value of dermatomal somatosensory evoked potentials（DSEP） by height calibration to the lumbosacral nerve root injury caused by lumbar disc herniations （LDH）.Method：In the first place,height of person was surveyed.Then fifty normal persons were measured by DSEP.L4,L5,S1 nerve roots of both sides were respectively examined and P40 latency data were acquired. Oneself height was divided by P40 latency in person.Fifty normal persons P40 latency of L4,L5,S1 nerve roots by height calibration were obtained by statistics.After that,ninety-six LDH cases with radiating pain only occured in one lower limb were measured by DSEP.L4,L5,S1 nerve roots of healthy and illness sides were respectively examined.The diagnostic standards of abnormal DSEP were （1）P40 wave disappeared, （2）P40 latency prolonged over 2.5 times standard difference of the normal person even data, （3）the sideway difference of P40 latency over 2.5 times standard difference of the healthy side even data.Result：P40 latency before height calibration in 50 normal persons were L4 nerve root 37.34±2.18ms,L5 nerve root 44.99±2.91ms,S1 nerve root 40.99±2.64ms.P40 latency after height calibration were L4 nerve root：height×（22.88± 1.08）ms,L5 nerve root：height×（27.55±1.34）ms,S1 nerve root：height×（25.06±1.11）ms.In 96 LDH cases,86 cases had abnormal DSEP without height calibration P40 latency.The diagnostic coincidence was 89.6%.After using height calibration P40 latency,92 cases had abnormal DSEP,the diagnostic coincidence was 95.8%（P〈 0.05）.Conclusion：DSEP can reflect the functional status of lumbosacral nerve roots.The diagnostic coincidence of DSEP can be raised by height calibration.It has an important value on evaluating the damage degree of nerve roots.