Identification of injury type using somatosensory and motor evoked potentials in a rat spinal cord injury model

The spinal cord is at risk of injury during spinal surgery.If intraoperative spinal co rd injury is identified early,irreve rsible impairment or loss of neurological function can be prevented.Different types of spinal cord injury result in damage to diffe rent spinal cord regions,which may cause diffe rent somatosensory and motor evoked potential signal res ponses.In this study,we examined electrophysiological and histopathological changes between contusion,distra ction,and dislocation spinal cord injuries in a rat model.We found that contusion led to the most severe dorsal white matter injury and caused considerable attenuation of both somatosensory and motor evoked potentials.Dislocation resulted in loss of myelinated axons in the lateral region of the injured spinal cord along the rostrocaudal axis.The amplitude of attenuation in motor evoked potential responses caused by dislocation was greater than that caused by contusion.After distraction injury,extracellular spaces were slightly but not significantly enlarged;somatosensory evoked potential res ponses slightly decreased and motor evoked potential responses were lost.Correlation analysis showed that histological and electrophysiological findings we re significantly correlated and related to injury type.Intraope rative monitoring of both somatosensory and motor evoked potentials has the potential to identify iatrogenic spinal cord injury type during surgery.

Correlation study between the changes of motor evoked potential and the improvement of spinal canal volume in minimally invasive transforaminal lumbar interbody fusion

Objective:To analyze the correlation between the amplitude changes of motor evoked potential(MEP),the 3D volume changes of spinal canal measuring by postoperative CT and the improvement rate of clinical symptoms after the spinal canal decompression in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF),and to explore the predictive value of the changes of both MEP amplitude and spinal canal volume in the assessment of long-term clinical prognosis in MIS-TLIF.Methods:A retrospective study of 68 patients with L4/5 spinal stenosis treated with MIS-TLIF was performed.The changes of both intraoperative MEP amplitude and 3D spinal canal volume during the spinal canal decompression,as well as the visual analogue scale(VAS)and Oswestry dysfunction index(ODI)scores in the long-term follow-up were all recorded.Results:The values of intraoperative MEP amplitude was 159.04%higher in 68 patients with MIS-TLIF after spinal canal decompression(P<0.01).The 3 postoperative 3D spinal canal volume(4.89±1.27)cm increased by 31.22%in comparison 3 with preoperative date(3.78±1.08)cm(P<0.01).The VAS and ODI scores were improved to 78.55%and 80.60%,respectively at the last follow-up(P<0.01).The improvement rate of MEP amplitude on the decompression side was positively correlated with the improvement rate of postoperative spinal canal volume(r=0.272,P=0.025).The improvement rate of postoperative spinal canal volume was positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.656,r=0.490,P<0.01).Moreover,the improvement rate of MEP amplitude on the decompression side was also positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.322 and 0.235,respectively,P<0.05).Conclusion:The increase of MEP amplitude after spinal canal decompression in patients with lumbar spinal stenosis treated by MIS-TLIF was closely correlated with both of the increase of spinal canal volume and the improvement of clinical symptoms.Therefore,MEP amplitude monitoring was not only the one of the important monitoring methods for predicting the prognosis of MIS-TLIF but also the reliably predictive value in the long-term clinical prognosis in MIS-TLIF.

INTRAOPERATIVE LOCALIZATION OF CORTICAL MOTOR EVOKED POTENTIALS IN CENTRAL SULCUS LESIONS

Objective To study direct cortical electrical stimulation technique for the recording of motor evoked potentials under general anesthesia in central sulcus lesions. Methods The largest N20-P25 response was recorded from postcentral gyrus by intraoperative monitoring of cortical motor evoked potentials in 10 patients with intracranial lesions near or in the central area. The muscles of upper extremity in all patients were activated by delivering stimulus to cortical areas continuously. Moving the cortical electrodes forward, the largest P20-N25 response, SEP phase reversal,was obtained as a motor center stimulus. In this site of cortex, a short train stimulation elicited reproducible muscle action potentials that could be observed from the oscilloscope without averaging.Results MEPs can be recorded, pre-and post-operatively, without motor deficits of upper limbs in all patients.Conclusion This technique seems to be preferable for intraoperative localization of motor evoked potentials in central sulcus lesions under total intravenous anesthesia.

Ipsilateral motor evoked potentials in a patient with unihemispheric cortical atrophy due to Rasmussen encephalitis

The role of the ipsilaterally descending motor pathways in the recovery mechanisms after unilateral hemispheric damage is still poorly understood. Motor output reorganization was investigated in a 56-year-old male patient with acquired unilateral hemispheric atrophy due to Rasmussen encephalitis. In particular,the ipsilateral corticospinal pathways were explored using focal transcranial magnetic stimulation. In the first dorsal interosseous and wrist extensors muscles, the median amplitudes of the ipsilateral motor evoked potentials induced by transcranial magnetic stimulation in the patient were higher than those of 10 age-matched healthy control subjects. In the biceps brachii muscle, the median amplitudes of the ipsilateral motor evoked potentials were the second largest in the patient compared to the controls. This study demonstrated a reinforcement of ipsilateral motor projections from the unaffected motor cortex to the hemiparetic hand in a subject with acquired unihemispheric cortical damage.

VALUE OF MOTOR EVOKED POTENTIALS BY MAGNETIC STIMULATION IN DIAGNOSIS OF LUMBOSACRAL RADICULOPATHY

Motor root conduction time(MRCT) was calculated by combining the magnetic stimulatiou eliciting motor evoked poentials (MEP)in lumbosacral region with F wave in popliteal rossa.Motor nerve conduction time(MNCT)and MRCT were calculated reliably from the tibialis and the soleal MEPS in 40 patients suffering from L5 or S1 radlculopathies owing to disc protrusion,and in 50 healthy controls.Meanwhile,corticals somatosensory evoked potentials(SEP)were recorded by segmental cutaneous nerve stimulation for comparison.The results showed that no differences were seen in MNCT in all patients,but MRCT was markedly prolonged in 85%or the patients,which was higher than the prolongation of SEP in 45% or the patients.It is concluded that magnetic stimulation of MEP is a useful technique ror non-invasive diagnosis of lumbosacral radlculopathies.

CLINICAL STUDY OF MOTOR EVOKED POTENTIALS BY MAGNETIC STIMULATION IN CERVICAL SPONDYLOTIC MYELOPATHY

The combined use of motor .yoked pot'ntlais (MEPs) with F way, recording was cornpared with somatesemory evoked potentials (SEPs) in order to evaluate the clinical value or MEPs incervical spondylotic myelopathy. Magnetic stimulation of motor cortex with F wave recording was used assess central motor conduction. time, (CMCT). and central somatoseusory conduction time(CSCT)was evaluated by SEPs in 20 pailents surffring from myeloP8thy of cervical spondylosis. Theresults were comapared with 20 control subjects. The results showed that CMCT of Patients was obviously prolonged then that of contral subjects, the sbnormal rate was 80% which was higher than70K of SEPs slid that the prolongation or CMCT had a good correlation with the severe degree ofmyelopathy. The Painless and noninvasive .magnetic stimulation of PEPs could figure out the compressed degree of motor descending pathway and was. useful technique for diagnosis of cervicalspondylotic myelopathy.

Cortical evoked potential changes in a rat model of acute ischemic stroke Detection of somatosensory evoked potential and motor evoked potential

BACKGROUND： Studies have shown that latency changes of some elements in a somatosensory evoked potential （SEP） and motor evoked potential （MEP） can reflect electrical activity of cerebral cortical neurons and conduction of white matter nerve fibers. However, there is a paucity of information regarding the dynamic observation of SEP and MEP following cerebral ischemic injury. OBJECTIVE： To explore SEP and MEP changes following acute ischemic stroke, and investigate the role of evoked potentials in monitoring brain function in stroke. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Chongqing Key Laboratory of Neurology, Affiliated Hospital of Chongqing Medical University from September 2007 to August 2008. MATERIALS＂ Hydrogen blood flow detector was purchased from Soochow University Medical Instrument Co., China, and Power lab system was purchased from AD Instruments, Inc., USA. METHODS A total of 36 healthy, adult, male, Sprague Dawley rats were randomly assigned to four groups （n = 9）, including three ischemia groups （12, 24 and 72 hours of ischemia） and a sham-surgery group. The rat model of acute ischemic stroke was established by middle cerebral artery occlusion （MCAO） in the left hemisphere. MAIN OUTCOME MEASURES＂ SEP and MEP of the left limbs were detected, and cerebral blood flow was measured by the hydrogen cleaning method. RESULTS： The latency of positive wave 1 （P1）, negative wave 1 （N1） and positive wave 2 （P2） waves in SEP, and latency of negative wave 1,2 （N1, N2） waves in MEP were significantly prolonged with increasing ischemic duration following MCAO （P 〈 0.01）, but cerebral blood flow was significantly decreased （P 〈 0.05, or P 〈 0.01）. CONLUSION： Ischemic stroke prolongs the latency of SEP waves （P1, N1, P2） and MEP waves （N1, N2）, and cerebral cortical evoked potential may correlate with cerebral blood flow changes. This indicates that SEP and MEP can be used to evaluate brain function following acute ischemic stroke.

Why do stroke patients with negative motor evoked potential show poor limb motor function recovery?

Negative motor evoked potentials after cerebral infarction, indicative of poor recovery of limb motor function, tend to be accompanied by changes in fractional anisotropy values and the cerebral pe-duncle area on the affected side, but the characteristics of these changes have not been reported. This study included 57 cases of cerebral infarction whose motor evoked potentials were tested in the 24 hours after the first inspection for diffusion tensor imaging, in which 29 cases were in the negative group and 28 cases in the positive group. Twenty-nine patients with negative motor evoked potentials were divided into two groups according to fractional anisotropy on the affected side of the cerebral peduncle： a fractional anisotropy 〈 0.36 group and a fractional anisotropy 〉 0.36 group. All patients underwent a regular magnetic resonance imaging and a diffusion tensor imaging examina- tion at 1 week, 1, 3, 6 and 12 months after cerebral infarction. The FugI-Meyer scores of their hemiplegic limbs were tested before the magnetic resonance and diffusion tensor imaging exami-nations. In the negative motor evoked potential group, fractional anisotropy in the affected cerebral peduncle declined progressively, which was most obvious in the first 1-3 months after the onset of cerebral infarction. The areas and area asymmetries of the cerebral peduncle on the affected side were significantly decreased at 6 and 12 months after onset. At 12 months after onset, the area asymmetries of the cerebral peduncle on the affected side were lower than the normal lower limit value of 0.83. FugI-Meyer scores in the fractional anisotropy ≥0.36 group were significantly higher than in the fractional anisotropy 〈 0.36 group at 3-12 months after onset. The fractional anisotropy of the cerebral peduncle in the positive motor evoked potential group decreased in the first 1 month after onset, and stayed unchanged from 3-12 months; there was no change in the area of the cerebral peduncle in the first 1-12 months after cerebral infarction. These findings confirmed that if the fractional anisotropy of the cerebral peduncle on the affected side is 〈 0.36 and the area asym-metries 〈 0.83 in patients with negative motor evoked potential after cerebral infarction, then poor hemiplegic limb motor function recovery may occur.

MOTOR EVOKED POTENTIAL OF MAGNETIC STIMULATION IN THE DETERMINATION OF S_1 RADICULOPATHY

Motor evoked potentlal (MEP) elicited by magnetic stimulation was utilised to diagnose S1 radiculopathy non-invasively. Magnetic stimulation estimated motor nerve conduction time (MNCT), which was used in combination with F response recorded from soleus, allowed calculation of motor root conduction time (MRCT). 50 healthy controls and 30 patients with S1 radiculopathy were studied- The results showed that no difference was seen in MNCT in all patients, but MRCT were markedly prolonged in 87% of the patients, which was higher than the prolongation of F wave latency in 71% or the patients. it is concluded that MEP of magnetic stimulation is a useful technique for non-invasive diagnosis of S, radiculopathy.

CORRELATION OF THE MAGNETIC MOTOR EVOKED POTENTIAL TECHNIQUE WITH PATHOLOGICAL CHANGES ASSOCIATED WITH SPINAL CORD INJURY IN ADULT CATS

To determine whether the pathological changes caused by injury to the spinal cord can be correlated with values obtained by the Magnetic Motor Evoked Potential (MEPs) technique, we studied spinal cords from 41 adult cats who were divided into 4 groups. The groups ranged from normal cats whose spinal cords were not compressed, to slightly, moderately and severely injured. MEPs were recorded before compression and in 30 minutes, 6 hours, 1 week, 2 week and 4 week after the compression unit was installed. Pathological changes with increased pressure were seen in blood vessels, nerve cells and fibers, Nissl substance and the central canal. A reversal of pathological changes was observed in slight or moderate injury during the 4 weeks of the experiment. Extensive injury, however, caused irreversible changes in the nerve cells with loss of motor function. The latency of MEPs at 30 minutes and 6 hours in the slightly injured group was 037 and 038 times greater than the baseline and returned to normal levels in 4 weeks. In the moderately injured group, the latency was increased 077 and 081 times and in the severely injured 132 and 136 times over the baseline. Recovery in the second group was partial and not at all in the severely injured. Thus, there appears to be good correlation between observed pathological changes, motor functions and MEPs.

Involuntary muscle spasm expressed as motor evoked potential after olfactory mucosa autograft in patients with chronic spinal cord injury and complete paraplegia

Object: The efficacy of olfactory mucosa autograft (OMA) for chronic spinal cord injury has been reported. New activity in response to voluntary effort has been documented by electromyography (EMG), but the emergence of motor evoked potential (MEP) reflecting electrophysiological conductivity in the central nervous system, including the corticospinal pathway, after OMA, and the best indications for OMA, have not been clarified. Here, we report the emergence of MEPs after OMA and offer recom-mendations for appropriate indications based on the presence of involuntary muscle spasm (IMS). We used analysis of MEP to examine the efficacy of OMA for patients with complete paraplegia due to chronic spinal cord injury. To clarify the indications for OMA, we investigated the association of IMS and efficacy of OMA. Methods: Four patients, 3 men and 1 woman, were enrolled. The mean age of the cases was 30.3 ± 9.5 years (range, 19 to 40 years). All 4 cases were American Spinal Injury Association (ASISA) grade A. The mean duration from injury to OMA was 95.8 ± 68.2 months (range, 17 to 300 months). Samples of olfactory mucosa were removed, cut into smaller pieces, and grafted into the sites of spinal cord lesions after laminectomy. Postoperative subcutaneous fluid collection, postoperative meningitis, postoperative nosebleed, postoperative infection in the nasal cavity, impaired olfaction, neoplastic tissue overgrowth at the autograft site, new sensory disturbance, and involuntary muscle spasm were investigated as safety issues. Improvements in ASIA grade, variations in ASIA scores, EMG, SSEP, and improved urological function were evaluated as efficacy indicators. Results: There were no serious adverse events in this series. In 2 of the 4 cases, an improvement in motor function below the level of injury was recognized. In one, the motor score was 50 until 16 weeks after surgery, and it increased to 52 from 20 weeks after surgery. In the other, the motor score was 50 until 20 weeks after surgery, and it increased to 52 at 24 weeks after surgery with a further increase to 54 at 48 weeks after surgery. The emergence of MEP was recognized in the latter case at 96 weeks after surgery. The other 2 cases had no improvement in ASIA motor score. Both of these cases who showed improvements in the ASIA motor scores exhibited relative IMS compared with those who had no ASIA motor score recovery. Conclusions: We recognized the emergence of MEPs in a case with complete paraplegia due to chronic spinal cord injury after OMA. IMS might be a candidate of indication of OMA.

Changes of evoked potential and expression of nestin in subventricular zones in rats after focal cerebral ischemia

Objective： To study the characteristics of latency of somatosensory evoked potential （SEP） and motor evoked potential （MEP） and the expression of nestin in subventricular zones （SVZ） after persistent focal cerebral ischemia in rats. Methods： The model of cerebral ischemia in rats was made by middle cerebral artery occlusion （MCAO）. All animals of ischemia were sacrificed after 12 h, 1 d, 3 d, 7 d, and 14 d to observe the changes of latency of SEP and MEP and to detect the expression of nestin, with an immunohistochemical approach. Results： The latencies of P1 （positive wave 1）, N1 （negative wave 1） and P2 （positive wave 2） in SEP were significantly prolonged after MCAO. The latencies of N1 and N2 waves in MEP were postponed gradually and no statistical difference of latency of N1 wave was found in rats at 7 d and 14 d after MCAO. The expression of nestin increased at 12 h, and showed a significant augmentation at 3 d and peaked at 7 d, then declined slightly at 14 d after MCAO. Conclusion： The cerebral ischemia prolonged the latency of EP waves and the expression of nestin was up-regulated and reached the peak at 7 d, showing the ischemia induced the proliferation of nervous stem cells. The SEP and MEP may evaluate the proliferation in SVZ after brain ischemia.

Recording of spared motor evoked potentials and its augmentation by 4-aminopyridine in chronic spinal cord-injured rats

Objective To research the direct electrophysiological evidence of discomplete spinal cord injury (SCI) and the effect of 4-aminopyridine on it.Methods Motor evoked potentials (MEPs), both spinal cord recorded MEPs (scMEPs) and extracellularly recorded MEPs (exMEPs) were recorded and characterized on a T13 epidural electrode (scMEPs) and an extracellular microelectrode (exMEPs) for 10 normal rats and 40 rats with lesions of various severity (sham, 35?g*cm force (gcf), 70?gcf, 100?gcf impact injury) at the T8-T9 cord using the Allen's drop model. The incline plane and Tarlov techniques were used to assess clinical neurological function. Results MEPs in the normal rats were elicited by applying transcortical suprathreshold stimulation consisting of 3-4 early negative peaks (N1, N2, N3 and N4) followed by several late waves. The N1 and N2 peaks were largest in the anterior and ventrolateral funiculus, respectively, which was indicative of extrapyramidal pathways. The 100?gcf impact injuries and the cord transection abolished the MEP distal to the lesion, whereas the 35?gcf injuries resulted in a latency shift and amplitude decrement of the MEP peaks. Eighteen of the 20 rats with 70?gcf injuries showed clinical paraplegia. Among them, 7 rats had neurophysiological evidence of residual conduction pathways through the lesioned cord segment, such as the presence of N1 and N2 peaks in the scMEPs or exMEPs. After 4-aminopyridine (4-AP) administrations (1?mg/kg), the amplitude of the spared exMEP increased significantly and spread more widely. Conclusions MEPs evoked by transcortical stimulation travel mostly in the extrapyramidal tract. MEP monitoring could provide an excellent method of detecting the functional integrity of the motor tracts after SCI, and could even detect spared motor fibers after discomplete SCI. Furthermore, the use of 4-AP or other K+ channel blocking agents may be a potential treatment for patients with chronic moderate to severe SCI.

无肌松药条件下气管插管后即刻监测运动诱发电位基线在腰椎手术中的应用

目的探讨腰椎手术在无肌松药气管插管后即刻监测运动诱发电位(TceMEP)基线的可行性。方法将2023年5-12月在徐州市中心医院拟行经椎间孔入路腰椎椎体间融合术(TLIF)的患者156例随机分为两组,最终对照组72例,男33例,女39例,观察组75例,男37例,女38例,对照组在术中脊柱暴露完成后监测TceMEP基线,观察组在无肌松药气管插管后即刻监测TceMEP基线。对比两组患者气管插管前后血流动力学变化、插管满意度和操作时间,并比较两组TceMEP基线引出成功率、刺激阈值、敏感性和特异性。结果两组患者气管插管时血流动力学变化与插管满意度差异无统计学意义(P>0.05),插管时间对照组为(6.52±1.22)min,观察组为(9.44±0.84)min,两组差异有统计学意义(P<0.05)。观察组TceMEP基线引出成功率为100%,平均刺激阈值(225.00±22.13)V,对照组TceMEP基线引出成功率为84.72%,平均刺激阈值(342.01±31.07)V,两组差异有统计学意义(P<0.05)。对照组在上钉后监测TceMEP成功率为93.06%,观察组为100%,两组差异有统计学意义(P<0.05)。两组TceMEP的敏感度和特异度差异无统计学意义(P>0.05)。结论无肌松气管插管后即刻监测TceMEP基线成功率高,刺激阈值小,敏感性与特异性与术中脊柱暴露完成后监测TceMEP基线无差别。

Intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation for preservation of facial nerve function in patients with large acoustic neuroma

Background Although various monitoring techniques have been used routinely in the treatment of the lesions in the skull base, iatrogenic facial paresis or paralysis remains a significant clinical problem. The aim of this study was to investigate the effect of intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation on preservation of facial nerve function. Method From January to November 2005, 19 patients with large acoustic neuroma were treated using intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation （TCEMEP） for preservation of facial nerve function. The relationship between the decrease of MEP amplitude after tumor removal and the postoperative function of the facial nerve was analyzed. Results MEP amplitude decreased more than 75% in 11 patients, of which 6 presented significant facial paralysis （H-B grade 3）, and 5 had mild facial paralysis （H-B grade 2）. In the other 8 patients, whose MEP amplitude decreased less than 75%, 1 experienced significant facial paralysis, 5 had mild facial paralysis, and 2 were normal. Conclusions Intraoperative TCEMEP can be used to predict postoperative function of the facial nerve. The decreased MEP amplitude above 75 % is an alarm point for possible severe facial paralysis.

表面肌电与运动诱发电位在脊髓运动完全性损伤评估中的比较

目的比较基于表面肌电图(sEMG)的脑运动控制方案和基于经颅磁刺激(TMS)的运动诱发电位在脊髓运动完全性损伤患者评估中的敏感性。方法纳入中国康复研究中心2021年3月—2023年4月收治的31例临床诊断为脊髓运动完全性损伤的患者,分别进行基于表面肌电的运动控制检测和基于TMS的运动诱发电位检测。结果31例患者中,27个(87%)至少有一个通道排名4或5。31例患者共测试了248块肌肉(每一例患者共测8块肌肉,分别是左右两侧的股直肌、股二头肌、胫前肌和腓肠肌),其中有79块(32%)肌肉可测量出通道排名4或5。62个肢体中的40个(64%)至少有一个通道排名4或5。31例患者中有21例(68%)有最高排名5的通道。然而,31例患者无一例能检测出运动诱发电位。结论sEMG在脊髓运动完全性损伤患者评估中的敏感性明显高于运动诱发电位。

多模式神经电生理监测在面肌痉挛MVD中的应用

目的探讨多模式神经电生理监测在面肌痉挛(HFS)显微血管减压术(MVD)中的应用效果。方法回顾性分析2020年12月至2022年3月MVD治疗的80例HFS的临床资料。术中应用异常肌电反应(AMR)、面神经运动诱发电位(FMEP)及自由肌电图(EMG)监测指导手术。结果术后1周治愈55例,明显缓解15例,部分缓解7例,无效3例;术后半年治愈57例,明显缓解10例,部分缓解9例,无效4例。术后1周治疗有效率为96.3%,术后半年治疗有效率为95.0%。术中AMR消失70例,存在10例;术中AMR消失病人术后1周(74.3%)、术后半年(78.6%)治愈率明显高于术中AMR存在的病人(分别为30.0%、20.0%;P<0.05)。80例术中均稳定引出FMEP,其中72例FMEP无变化;6例出现一过性波幅降低和(或)潜伏期延长,暂停手术操作后恢复;2例出现波幅降低且暂停手术操作无改善,术后出现面瘫。80例在分离和探查面神经REZ时均出现EMG不同程度的反应,其中一过性反应71例;持续出现的面神经爆发肌电图反应9例,暂停手术操作后缓解。结论术中AMR+FMEP+EMG多模式电生理监测技术对MVD判断责任血管、提高治愈率、保护面神经功能及避免并发症具有重要作用。

电刺激运动诱发电位(MEP)临床研究进展

运动诱发电位(motor evoked potential,MEP)应用于临床已有二十多年的历史,其中电刺激MEP广泛地应用于运动神经系统疾病的诊断和术中监护。随着监测技术和麻醉技术的进步,电刺激MEP术中监测的价值和可靠性进一步提高,应用范围越来越广,安全性也得到不断改善。但目前仍存在一些问题,如缺乏统一的预警标准,多学科的合作不足等。本文就MEP术中应用的现状、安全性及麻醉对它的影响进行综述。

面神经ENoG和MEP检查在面肌麻痹诊断及预后方面的应用

应用面神经电图(ENoG)和面神经运动诱发电位(MEP),对60名正常人(ENoG30名,MEP30名)和40例面肌麻痹患者(ENoG20例,MEP20例)的测试结果表明:①ENoG是1种客观的电生理诊断技术,能较准确地反映面神经纤维状态,对诊断和判断预后有指导意义。但在面肌麻痹早期,仅靠此项检查来判断预后不够,还需结合其它电生理检查。②MEP是1种新的测试方法,能通过颅骨刺激到颅内近端面神经,对了解近端面神经状态大有帮助。初步研究表明,该技术安全、可靠,诱发电位重复性好,正常人与患者间差异显著。③两种方法结合使用,有助于早期了解病变的性质和程度,较全面地了解面神经的完整性,对判断预后,拟定治疗方案有重要意义。

不同神经肌肉阻滞程度对经颅电刺激运动诱发电位(MEPs)的影响

目的 比较不同神经肌肉阻滞程度对经颅电刺激运动诱发电位（motor evoked potentials,MEPs）的影响,为术中MEPs监测选择合适的神经肌肉阻滞程度提供依据。方法 选取择期神经外科手术患者20例,年龄22～65岁,ASAⅠ～Ⅱ级。选择拇短展肌作为记录肌肉,采用经颅电刺激技术记录MEPs,刺激参数为：电压300 V,频率1 000 Hz,持续时间75 μs,脉冲数6个/串。采用丙泊酚复合瑞芬太尼全凭静脉麻醉,维库溴铵持续输注维持肌松,分别记录4个成串刺激（train of four stimulations,TOF）为0、1、2和4时的MEPs波幅和潜伏期变化情况。结果 TOF为0～4时均可记录到MEPs波幅。TOF为0与TOF为1、2和4之间的波幅差异均有统计学意义（P均〈0.001）;TOF为1、2和4之间的差异均无统计学意义;MEPs潜伏期变化不显著（F=0.050,P=0.980）。结论 在丙泊酚复合瑞芬太尼全凭静脉麻醉下,神经肌肉阻滞剂对MEPs有显著的抑制作用,MEPs波幅随着神经肌肉阻滞程度的加深而减小,但在较深的神经肌肉阻滞程度下（TOF=1）仍可监测MEPs。