磁刺激运动诱发电位在腰椎间盘突出所致的腰骶神经根病变…

在３５例有Ｌ５和／或Ｓ１神经根损害表现的腰椎间盘突出患者椎区进行磁刺激运动诱发电位检查，测定，主戏前肌，Ｍｕ展肌和小趾展肌ＭＥＰ的起始潜伏期。结果显示，３５例中至少有一条患侧肌肉ＭＥＰ异常３３例。     

腰椎退变性疾病致足下垂的临床特点及其预后影响因素

【摘要】 目的：分析腰椎退变性疾病致足下垂的临床特点,探讨影响其预后的因素。方法：2005年1月~2010年1月,手术治疗1674例腰椎间盘突出症和/或腰椎管狭窄症患者,其中135例合并足下垂,男62例,女73例;年龄43~64岁,平均55岁。术前胫前肌肌力：0级18例,1级34例,2级59例,3级24例。均行椎弓根螺钉内固定、神经根减压、改良腰后路椎间融合术治疗。术后随访1~2年,平均1.3年,观察胫前肌肌力恢复情况。统计患者年龄、性别、病程、术前胫前肌肌力、下肢感觉障碍、受累足、受压神经根,分析其对术后胫前肌肌力恢复的影响。结果：足下垂占同期患者的8.1%。43例（32.8%）单条神经根受压（L5 34例,S1 7例,L4 2例）,83例（61.5%）2条神经根受压（L5、S1 56例,L4、L5 27例）,9例（6.7%）3条神经根受压（L4、L5、S1）。共有126例患者（93.3%）L5神经根受压。术后113例（83.7%）患者胫前肌肌力有所恢复,其中21例（15.6%）恢复至4级及以上。术后6个月随访时患者胫前肌肌力恢复基本稳定。末次随访时患者胫前肌肌力：1级28例,2级24例,3级62例,4级13例,5级8例。足下垂病程、术前胫前肌肌力和患者年龄与手术效果相关。结论：在腰椎退变性疾病致足下垂的患者中L5神经根受压最常见,多条神经根受压常见;足下垂一旦发生,预后不佳;足下垂病程、术前胫前肌肌力以及年龄是影响胫前肌肌力恢复的重要因素,应预防其发生及早期治疗。     

神经肌电图在腰椎间盘突出症诊断中的应用价值分析

目的探讨神经肌电图检查在腰椎间盘突出症诊断中的应用价值。方法对40例腰椎间盘突出症患者进行神经肌电图、腰椎MRI检查,并进行腰椎JOA评分,分析神经肌电图的临床特点及与腰椎MRI、JOA评分的相关性。结果 40例腰椎间盘突出症患者,神经肌电图异常37例,其中L5、S1神经根较常受累,其次是L4神经根受累,多累及1～2个神经根节段,与腰椎MRI所示的受累神经节段一致。神经肌电图与腰椎MRI结果完全符合34例(85%),不符合6例(15%),其中3例(7.5%)神经肌电图正常,但腰椎MRI有椎间盘突出表现,另外3例(7.5%)均表现为腰椎MRI L3/4、 L4/5椎间盘突出,但神经肌电图显示S1神经根亦受累。神经肌电图评分与腰椎MRI分级呈正相关(OR=0.436,P=0.005),而与JOA评分呈负相关(OR=-0.424,P=0.006)。结论神经肌电图与腰椎MRI反映腰椎间盘突出症受累神经根节段一致性较高,能弥补腰椎MRI检查的不足,反映神经根受压的严重程度。     

腰5骶1椎间盘突出的临床特点

目的:探讨L5/S1椎间盘突出的临床特点以提高临床诊断正确率。方法:回顾分析188例腰椎间盘突出病人的临床资料,对另96例L5/S1、88例L4/5椎间盘突出病人进行详细临床检查并总结分析。结果:L5/S1椎间盘突出特点为:鞍区感觉（针刺、轻触、温度觉）迟钝;括约肌功能减退;跪位踝反射减弱或消失;直腿抬高试验度数偏高;单足下蹲试验常呈阳性等。结论:L5-5/S1椎间盘突出的临床特点有助于腰椎间盘突出的定位诊断。     

髂骨转移癌误诊腰椎间盘突出症一例

患者，女，46岁，因右下肢疼痛、麻木、无力并间歇性跛行半年入院，入院前在外院行腰椎CT片示：L4、5、L5S1椎间盘膨出，L5S1层面右侧神经根轻度受压，硬膜囊未见受压；腰椎MRI示：腰椎退变，椎间盘变性，L4、5、L5S1椎间盘膨出。在外院考虑腰椎间盘突出症行非手术治疗一个月无明显疗效，建议患者手术治疗。然后转入我院时查体：腰背     

腰椎曲度与腰椎间盘突出的影像学研究

目的利用影像学手段研究中青年腰椎曲度与L5S1椎间盘突出之间的关系,并探讨其临床意义。方法随机选取2015年9月至2016年2月18~40岁行腰椎MRI检查者369例,其中L5S1椎间盘突出组184例,正常对照组185例。在T2WI正中矢状位上测量腰骶角与腰椎前凸角度,应用两独立样本t检验比较腰椎间盘突出者与对照组间及男女间腰骶角、腰椎前凸角度的差异性。结果 L5S1腰椎间盘突出组与对照组间腰骶角、腰椎前凸角度的差异均具有显著统计学意义(P0.001);L5S1腰椎间盘突出组中男女间腰骶角的差异有统计学意义(P0.05)。结论腰椎曲度与L5S1椎间盘突出具有相关性,腰骶角与腰椎前凸角度能评价两者之间的相关性。腰椎曲度变小即腰骶角减小或腰椎前凸角度减小,易增加L5S1椎间盘突出的发生率,提示可以通过测量腰骶角、腰椎前凸角度来帮助人们提前发现腰椎间盘突出,做好防范。     

手法为主综合治疗腰椎间盘突出手术后复发

腰椎间盘突出症所引起的腰腿痛,目前多主张以保守治疗为主,但经手术治疗的也有一定比率。自2000年10月-2005年12月共收治经手术后复发的腰椎间盘突出症19例,临床应用松肌法、分离神经根粘连法、骨盆旋转整脊法、后伸压腰法、纠正脊柱侧弯法为主,结合骨盆牵引中药熏蒸,药物对症治疗为辅,取得了满意的效果。为探究其疗效机制,现总结如下。1临床资料1.1一般资料19例中,男16例,女3例;年龄26~59岁。有劳损、外伤及受凉诱发者12例。发病部位据CT、MRI检查统计:L3,4椎间盘突出1例,L4,5椎间盘突出9例,L5S1椎间盘突出5例,L4,5和L5S1两节段椎间盘…     

脊髓造影在腰椎间盘突出症术前的应用

目的：探讨用脊髓造影在腰椎间盘突出症术前应用的临床价值。方法：收集临床诊断、CT扫描为腰椎间盘突出症34例进行脊髓造影的检查。结果：4例发现椎管占位，其中T11平面1例，T12－L1平面2例，L5平面1例。在L1－2，L2－3间隙各发现一例CT未报告的椎间盘侧突，经手术治疗得到证实。有17例（21个间隙）发现神经根袖消失或呈“锯齿”状。结论：腰椎间盘突出症在术前应常规行脊髓造影，可以明确诊断、准确定位，便于选择最佳手术方法，获得最好的治疗效果。     

磁刺激腰骶部神经根的兴奋点及其在腰骶神经根病中的应用

采用磁刺激腰骶部的神经根运动诱发电位（MEPs）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，并根据MRCT推算磁刺激腰骶部神经根的兴奋点位置，结合5例尸解测出的L5和S1神经根的长度，确定该兴奋点在椎间孔的近端。同样方法记录和观察40例手术证实单侧L5或S1神经根受压患者MNCT和MRCT的改变。结果显示：病人组与正常组相比MNCT无显著性差异，而MRCT有显著性差异，异常率为85％。作者认为，无痛无创的磁刺激MEPs对腰骶神经根病有很大的诊断价值。     

中央型腰椎间盘突出症的手术治疗68例报告

中央型腰椎间盘突出临床少见，国内报告其发病率为3．6％～14．2％[1、2、3]。由于突出椎间盘可压迫单、双侧神经根及马尾神经，使临床症状复杂多变，给诊断和治疗带来一定困难。我院自1985年以来收治腰椎间盘突出症1256例，中央型68例，占5．4％，现就诊断与治疗认识回顾如下：1临床资料1．1一般资料本组68例，男42例，女26例；年龄19～63岁，平均43岁；职业：农民38例，工人20例，干部10例；腰部闪扭伤史68例，部位L（3、4）2例，L（4、5）34例，L5S125例，L（3、4）L5S1双间隙1例，L（4、5）、L5S1双间隙6例。入院前患者分别接受手法…     

Tetanic stimulation of the peripheral nerve before transcranial electrical stimulation can enlarge amplitudes of myogenic motor evoked potentials during general anesthesia with neuromuscular blockade

BACKGROUND: Neuromuscular blockade can suppress myogenic motor evoked potentials (MEPs). The authors hypothesized that tetanic stimulation (TS) of the peripheral nerve before transcranial stimulation may enhance myogenic MEPs during neuromuscular blockade. In the current study, the authors evaluated MEP augmentations by TS at different levels of duration, posttetanic interval, neuromuscular blockade, and stimulus intensity. METHODS: Thirty-two patients undergoing propofol-fentanyl-nitrous oxide anesthesia were examined. Train-of-five stimulation was delivered to C3-C4, and MEPs were recorded from the abductor hallucis muscle. In study 1, TS with a duration of 1, 3, or 5 s was delivered at 50 Hz to the tibial nerve 1, 3, or 5 s (interval) before transcranial stimulation, and the effects of TS on MEP amplitude were evaluated. In study 2, TS-induced MEP augmentations were evaluated at the neuromuscular blockade level (%T1) of 50% or 5%. In study 3, MEP augmentations by TS at stimulus intensities of 0, 5, 25, and 50 mA were evaluated. RESULTS: The application of TS significantly enlarged the amplitudes of MEPs at the combinations of duration (3, 5 s) and interval (1, 3, 5 s) compared with those without TS. TS-induced MEP augmentations were similarly observed at %T1 of both 50% and 5%. TS-induced MEP augmentations were observed at stimulus intensities of 25 and 50 mA. CONCLUSIONS: The results indicate that TS of the peripheral nerve before transcranial stimulation can enlarge the amplitude of MEPs during general anesthesia with neuromuscular blockade. TS of the peripheral nerve can be intraoperatively applied as a method to augment myogenic MEP responses.     

外周神经强直刺激对脑功能区肿瘤切除术患者颅内直接电刺激运动诱发电位的影响

目的 探讨外周神经强直刺激对脑功能区肿瘤切除术患者颅内直接电刺激运动诱发电位(MEP)的影响.方法 择期拟行神经外科脑功能区肿瘤切除术患者8例,异丙酚复合芬太尼麻醉,在肌松监测下单次静脉注射维库溴铵,维持部分肌松.给予颅内运动区皮质及皮质下锥体束5个成串刺激,分别记录两组数据.第一组在一侧拇短展肌记录常规MEP(C-MEP),同侧胫神经给予持续时间5 s、频率50 Hz、强度50 mA的强直刺激,刺激后1 s以同样方法记录强直刺激后MEP(P-MEP).第二组在一侧胫骨前肌记录C-MEP,对侧胫神经给予持续时间5 s、频率50 Hz、强度50 mA的强直刺激,刺激后1 s以同样方法记录P-MEP.每一组C-MEP的记录和P-MEP的记录采用随机交叉的方法,间隔时间为120 s,观察不良反应的发生情况.结果 在拇短展肌和胫骨前肌记录的MEP波幅,P-MEP明显高于C-MEP,3例患者术中皮质刺激时出现体动.无术中知晓及其他与电刺激有关的并发症发生.结论 外周强直刺激可以增大脑功能区肿瘤切除术患者拇短展肌与胫骨前肌颅内直接电刺激MEP的波幅.     

Tetanic Stimulation of the Peripheral Nerve before Transcranial Electrical Stimulation Can Enlarge Amplitudes of Myogenic Motor Evoked Potentials during General Anesthesia with Neuromuscular Blockade

Background: Neuromuscular blockade can suppress myogenic motor evoked potentials (MEPs). The authors hypothesized that tetanic stimulation (TS) of the peripheral nerve before transcranial stimulation may enhance myogenic MEPs during neuromuscular blockade. In the current study, the authors evaluated MEP augmentations by TS at different levels of duration, posttetanic interval, neuromuscular blockade, and stimulus intensity.

Methods: Thirty-two patients undergoing propofol-fentanyl-nitrous oxide anesthesia were examined. Train-of-five stimulation was delivered to C3-C4, and MEPs were recorded from the abductor hallucis muscle. In study 1, TS with a duration of 1, 3, or 5 s was delivered at 50 Hz to the tibial nerve 1, 3, or 5 s (interval) before transcranial stimulation, and the effects of TS on MEP amplitude were evaluated. In study 2, TS-induced MEP augmentations were evaluated at the neuromuscular blockade level (%T1) of 50% or 5%. In study 3, MEP augmentations by TS at stimulus intensities of 0, 5, 25, and 50 mA were evaluated.

Results: The application of TS significantly enlarged the amplitudes of MEPs at the combinations of duration (3, 5 s) and interval (1, 3, 5 s) compared with those without TS. TS-induced MEP augmentations were similarly observed at %T1 of both 50% and 5%. TS-induced MEP augmentations were observed at stimulus intensities of 25 and 50 mA.     

Motor evoked potential study suggesting L5 radiculopathy caused by l1-2 disc herniation: case report

A 38-year-old male was referred because of pain in the left 5th lumbar (L5) root territory. Physical examination found moderate motor weakness in the left extensor hallucis longus (EHL) and the left tibialis anterior muscles. Magnetic resonance imaging found no stenotic lesion between L4-L5, but disc herniation was observed on the left between L1-L2. An L5 nerve root block provided temporary relief of the pain but the left foot weakness was exacerbated. Therefore, surgery was performed. Partial laminectomy and left herniotomy were performed at L1-L2, L2-L3, and L3-L4 with motor evoked potential (MEP) monitoring. The MEP amplitude of the left EHL muscle increased immediately after L1-L2 herniotomy. The MEP amplitude of the right EHL muscle also increased after both laminectomy and herniotomy. The postoperative course was uneventful. The left leg pain and motor weakness disappeared. The patient has been doing fine without recurrence for 12 months. Since the MEP of both left and right EHL muscles improved after the L1-2 herniotomy, circulatory insufficiency might have caused the L5 symptoms. Monitoring of the MEP during the surgery was useful for confirming the responsible lesion and also for predicting the postoperative course.     

Evaluation of the applicability of sevoflurane during post-tetanic myogenic motor evoked potential monitoring in patients undergoing spinal surgery

Purpose  Recent evidence has indicated that post-tetanic motor evoked potentials (p-MEPs) can be used to improve the reliability of the monitoring of motor function during spinal surgery. However, data on p-MEP monitoring are limited to those in subjects under propofol anesthesia. The present study was conducted to assess the applicability of sevoflurane during p-MEP monitoring in patients undergoing spinal surgery. Methods  Thirty-five patients undergoing spinal surgery under sevoflurane anesthesia were enrolled in the study and classified as being without preoperative motor deficits (n = 25) or with preoperative motor deficits (n = 10). For conventional MEP (c-MEP), transcranial train-pulse stimulation was delivered and the compound muscle action potentials were bilaterally recorded from the abductor pollicis brevis, abductor hallucis, tibialis anterior, and soleus muscles. For p-MEP, tetanic stimulation (50 Hz, 50 mA stimulus intensity) for 5 s was applied to the bilateral median and left tibial nerves 1 s prior to transcranial stimulation. Results  The amplitudes of p-MEP were significantly higher in all muscle recording sites than those of c-MEP in patients without motor deficits, whereas these amplitudes were significantly higher in only four of the eight muscles in patients with motor deficits (P < 0.05). The success rates of c-MEP and p-MEP recording were 48% and 64%, respectively, in patients without motor deficits and 30% and 60%, respectively, in patients with motor deficits. There were no statistically significant differences in success rates between c-MEP and p-MEP recording. Conclusion  Although the application of tetanic stimulation prior to transcranial stimulation did not significantly increase the success rates of MEP recording, it significantly enlarged MEP amplitude under sevoflurane anesthesia in patients without preoperative motor deficits.     

Noxious stimuli do not modify myogenic motor evoked potentials by electrical stimulation during anesthesia with propofol-based anesthesia

PURPOSE: To investigate whether motor evoked potentials (MEP) to transcranial electrical stimulation under constant blood propofol concentration are affected by the arousing effect of surgical noxious stimuli. METHODS: Twenty patients who underwent elective spinal surgery were studied. Patients were anesthetized with 50% nitrous oxide in oxygen, fentanyl, and propofol to maintain the bispectral index (BIS) score around 50. MEP in response to a multipulse transcranial electrical stimulation at stimulus sites of C3-C4 were recorded over the right abductor pollicis brevis muscle. Changes of peak-to-peak amplitude and onset latency of MEP, BIS score before and after surgical stimuli were evaluated. Propofol plasma concentration was measured at the same time points. RESULTS: Both MEP amplitude and latency did not change significantly after surgical stimuli although BIS increased significantly (48 +/- 6 to 58 +/- 5; P < 0.05). Plasma propofol concentration was maintained at the same level between the two measurement points (3.3 +/- 0.7 to 3.3 +/- 0.7 micro g*mL(-1)). There was no relation between BIS change and changes of MEP amplitude and latency, and propofol plasma concentration. CONCLUSION: MEP to the transcranial electrical stimulation under a constant and clinically appropriate blood propofol concentration are not affected by surgical noxious stimuli.     

Quantitative assessment of myelopathy patients using motor evoked potentials produced by transcranial magnetic stimulation

Motor evoked potentials (MEPs) study using transcranial magnetic stimulation (TMS) may give a functional assessment of corticospinal conduction. But there are no large studies on MEPs using TMS in myelopathy patients. The purpose of this study is to confirm the usefulness of MEPs for the assessment of the myelopathy and to investigate the use of MEPs using TMS as a screening tool for myelopathy. We measured the MEPs of 831 patients with symptoms and signs suggestive of myelopathy using TMS. The MEPs from the abductor digiti minimi (ADM) and abductor hallucis (AH) muscles were evoked by transcranial magnetic brain stimulation. Central motor conduction time (CMCT) is calculated by subtracting the peripheral conduction time from the MEP latency. Later, 349 patients had surgery for myelopathy (operative group) and 482 patients were treated conservatively (nonoperative group). CMCTs in the operative group and nonoperative group were assessed. MEPs were prolonged in 711 patients (86%) and CMCTs were prolonged in 493 patients (59%) compared with the control patients. CMCTs from the ADM and AH in the operative group were significantly more prolonged than that in the nonoperative group. All patients in the operative group showed prolongation of MEPs or CMCTs or multiphase of the MEP wave. MEP abnormalities are useful for an electrophysiological evaluation of myelopathy patients. Moreover, MEPs may be effective parameters in spinal pathology for deciding the operative treatment.     

Effects of incremental ketamine hydrochloride doses on motor evoked potentials (MEPs) following transcranial magnetic stimulation: a primate study

the cumulative dose effect of ketamine hydrochloride (KH) on transcranial magnetic-induced motor evoked potentials (MEPs) was examined in monkeys. Electromyographic (EMG) responses were recorded from the contralateral abductor pollicis brevis (APB) and abductor hallucis (AH) muscles. MEP brain stimulation threshold, latency, and amplitude values were studied. After obtaining baseline recordings, increments of KH (5 mg/kg every 15-20 min) were given i.v. (50 mg/kg total dose). MEPs were repeatedly recorded following KH injections. No loss of potentials was encountered in any animal. However, KH induced significant MEP latency delay in doses >/=35-40 mg/kg and amplitude depression in doses >/=15-20 mg/kg (p < 0.01). Under various KH doses, the amplitude depression ranged from 13.6 to 45.5% for APB and 57.3 to 82% for AH compared to the control values. The MEP latency prolongation ranged from 3.5 to 18% for APB and 4.2 to 13.1% for AH. The stimulation threshold rise ranged from 6.7 to 14.7% for APB and 7 to 17.9% for AH. Statistical correlation was closest between cumulative KH doses and MEP latency prolongation. We conclude that, in the primate model, reliable MEP recording is feasible under deep KH anesthesia. However, awareness of drug-induced response alterations is essential during interpretation of intraoperative MEP changes. Further investigation is warranted regarding the specific dose effect in humans and safety of magnetic stimulation.     

Transcranial electrical motor evoked potential monitoring for brain tumor resection

OBJECTIVE: This study was designed to examine whether transcranial electrical motor evoked potential (MEP) monitoring is safe, feasible, and valuable for brain tumor surgery. METHODS: Fifty consecutive patients undergoing brain tumor resection were studied, using nitrous oxide/propofol anesthesia. MEPs were continuously recorded throughout surgery, using a Sentinel 4 evoked potential system (Axon Systems, Inc., Hauppauge, NY). The MEPs were elicited by transcranial electrical stimulation (train of 5; stimulation rate, 0.5-2 Hz; square wave pulse with a time constant of 0.5 ms; stimulation intensity, 40-160 mA) through spiral electrodes placed over the primary motor cortex and were recorded by needle electrodes inserted into the contralateral orbicularis oris, biceps, abductor pollicis brevis, and anterior tibialis muscles. When MEP amplitudes decreased by more than 50%, MEP stimulation was repeated, with increased stimulation intensity, and MEP changes were reported to the surgeon. The motor function of each patient was examined before and after surgery, using a reproducible scale. The relationship between MEP amplitude decreases and worsening motor status was analyzed using linear regression. RESULTS: Preoperative neurological examinations revealed mild to moderate motor deficits (2/5 to 4/5) for 38% of patients (19 of 50 patients). Most of the patients (96%) exhibited recordable baseline MEPs. Persistent MEP decreases of more than 50% were noted for eight patients (16%) (11 muscles). The MEPs were completely abolished in two patients (three muscles). The degree of postoperative worsening of motor status was correlated with the degree of intraoperative MEP amplitude reduction (r = -0.864; P < 0.001). CONCLUSION: Persistent intraoperative MEP reductions of more than 50% were associated with postoperative motor deficits. The degree of MEP amplitude reduction was correlated with postoperative worsening of motor status. Transcranial electrical MEP monitoring is feasible, safe, and valuable for brain tumor surgery.     

The effect of etomidate on motor evoked potentials induced by transcranial magnetic stimulation in the monkey

Etomidate (ET) is a known hypnotic agent in neuroanesthesia. This study was designed to examine the reliability of motor evoked potentials (MEPs) after transcranial magnetic stimulation in monkeys anesthetized intravenously with ET. The ET regimen was as follows: an initial dose (0.5 mg/kg) followed by 13 doses (0.2 mg/kg every 6-12 min; mean, 8.0 +/- 1.3 min). The total dose administered was 3.1 mg/kg. The magnetic coil was placed over the MEP scalp stimulation region. Evoked electromyographic responses were recorded from the contralateral abductor pollicis brevis (APB) and abductor hallucis (AH) muscles of the fore- and hindlimbs, respectively. Reproducible MEP responses were consistently recorded while the animal was under total ET anesthesia. The coil demography was altered and the MEP scalp topography was moderately reduced by ET injections. Significant threshold elevation was noted after a total dose of 1.7 mg/kg for APB responses and 0.5 mg/kg for AH responses (P less than 0.05). Marked prolongation of latency was observed after a dose of 0.5 mg/kg for APB MEPs and 2.5 mg/kg for AH MEPs (P less than 0.05). MEP amplitude responses showed marked variability. Repeated doses of ET produced a mean threshold rise of 14 to 28% for the APB and 19 to 29% for the AH. The mean latency delay was 5 to 11% for the APB and 0.5 to 8% for the AH, while the mean amplitude depression was 24 to 59% for the APB and 15 to 50% for the AH. Apparent seizure activity or abnormalities in behavior and feeding were not noted over a 1-year period.(ABSTRACT TRUNCATED AT 250 WORDS)