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.

Effects of different frequencies of repetitive transcranial magnetic stimulation on the recovery of upper limb motor dysfunction in patients with subacute cerebral infarction

Studies have confirmed that low-frequency repetitive transcranial magnetic stimulation can decrease the activity of cortical neurons, and high-frequency repetitive transcranial magnetic stimulation can increase the excitability of cortical neurons. However, there are few studies concerning the use of different frequencies of repetitive transcranial magnetic stimulation on the recovery of upper-limb motor function after cerebral infarction. We hypothesized that different frequencies of repetitive transcranial magnetic stimulation in patients with cerebral infarction would produce different effects on the recovery of upper-limb motor function. This study enrolled 127 patients with upper-limb dysfunction during the subacute phase of cerebral infarction. These patients were randomly assigned to three groups. The low-frequency group comprised 42 patients who were treated with 1 Hz repetitive transcranial magnetic stimulation on the contralateral hemisphere primary motor cortex （M1）. The high-frequency group comprised 43 patients who were treated with 10 Hz repetitive transcranial magnetic stimulation on ipsilateral M1. Finally, the sham group comprised 42 patients who were treated with 10 Hz of false stimulation on ipsilateral M1. A total of 135 seconds of stimulation was applied in the sham group and high-frequency group. At 2 weeks after treatment, cortical latency of motor-evoked potentials and central motor conduction time were significantly lower compared with before treatment. Moreover, motor function scores were significantly improved. The above indices for the low- and high-frequency groups were significantly different compared with the sham group. However, there was no significant difference between the low- and high-frequency groups. The results show that low- and high-frequency repetitive transcranial magnetic stimulation can similarly improve upper-limb motor function in patients with cerebral infarction.

EFFECTS OF TRANSCRANIAL MAGNETIC STIMULATION ON MOTOR CORTICAL EXCITABILITY AND NEUROFUNCTION AFTER CEREBRAL ISCHEMIA-REPERFUSION INJURY IN RATS

Objective To clarify the effects of repetitive transcranial magnetic stimulation (rTMS) on rat motor cortical excitabi- lity and neurofunction after cerebral ischemia-reperfusion injury. Methods After determined awake resting motor threshold (MT) and motor evoked potentials (MEPs) of right hindlimbs, 20 Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) reperfusion injury, then rTMS were applied to rTMS group (n = 10) at different time, while control group (n = 10) received no stimulation. A week later, MT and MEPs were evaluated again, as well as neurological deficits and infarct volume. The effects of rTMS and MCAO reperfusion injury on these parameters were analyzed. Results After MCAO reperfusion, both MT level and neurological deficit scores increased, distinct focal infarction formed, and latency of MEP elongated. Compared with the control group, the increased extent of MT and neurological scores of rats receiving rTMS were significantly lower (P < 0.05), as well as the infarct volumes reduced significantly(P < 0.05). But MEP was not affected by rTMS obviously. There was a positive linear correlation between postinjury MT and infarct volume (r = 0.64, P < 0.05). Conclusion rTMS may facilitate neurofunction recovery after cerebral ischemia-reperfusion. Postinjury MT could provide prognostic information after MCAO reperfusion injury.

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.

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.

Nerve root magnetic stimulation improves locomotor function following spinal cord injury with electrophysiological improvements and cortical synaptic reconstruction

Following a spinal cord injury,there are usually a number of neural pathways that remain intact in the spinal cord.These residual nerve fibers are important,as they could be used to reconstruct the neural circuits that enable motor function.Our group previously designed a novel magnetic stimulation protocol,targeting the motor cortex and the spinal nerve roots,that led to significant improvements in locomotor function in patients with a chronic incomplete spinal cord injury.Here,we investigated how nerve root magnetic stimulation contributes to improved locomotor function using a rat model of spinal cord injury.Rats underwent surgery to clamp the spinal cord at T10;three days later,the rats were treated with repetitive magnetic stimulation(5 Hz,25 pulses/train,20 pulse trains)targeting the nerve roots at the L5-L6 vertebrae.The treatment was repeated five times a week over a period of three weeks.We found that the nerve root magnetic stimulation improved the locomotor function and enhanced nerve conduction in the injured spinal cord.In addition,the nerve root magnetic stimulation promoted the recovery of synaptic ultrastructure in the sensorimotor cortex.Overall,the results suggest that nerve root magnetic stimulation may be an effective,noninvasive method for mobilizing the residual spinal cord pathways to promote the recovery of locomotor function.

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.

小针刀联合经颅磁刺激治疗脑梗死后遗症期上肢痉挛的疗效观察

目的:研究小针刀联合经颅磁刺激(Transcranial Magnetic Stimulation.TMS)在改善脑梗死后遗症期患者上肢痉挛症状中的临床疗效。方法:选取2021年6月~2023年6月在本院就诊的80例脑梗死后遗症期上肢轻至中度痉挛患者,随机将其分为小针刀组(n=26)、TMS组(n=27)、联合组(n=27)。所有患者在常规康复训练基础上,小针刀组进行小针刀治疗,TMS组进行经颅磁治疗,联合组进行联合治疗。治疗前后评估患者的Fugl-Meyer量表分数、临床痉挛指数分数,运动诱发电位,和静息运动阈值。结果:三组患者治疗后Fugl-Meyer评分均提高,临床痉挛指数评分均下降(P<0.01),其中联合治疗组的FuglMeyer评分高于单一治疗组,临床痉挛指数评分低于单一治疗组(P<0.01):三组患者治疗后运动诱发电位潜伏期均缩短,波幅增高(P<0.01),其中联合治疗组的运动诱发电位潜伏期短于单一治疗组,波幅高于单一治疗组(P<0.01):三组患者治疗后静息运动阈值均下降(P<0.01),其中联合治疗组的静息运动阈值低于单一治疗组(P<0.01)。结论:小针刀联合经颅磁刺激治疗能有效缓解脑梗死后上肢功能痉挛患者的上肢痉挛、中枢神经系统功能及大脑皮层兴奋性,疗效优于单一治疗方法。

Effect of Paired Associative Stimulation on Motor Cortex Excitability in Rats

Paired associative stimulation (PAS),combining transcranial magnetic stimulation (TMS) with electrical peripheral nerve stimulation (PNS) in pairs with an optimal interstimulus interval (ISI)in between,has been shown to influence the excitability of the motor cortex (MC)in humans.However,the underlying mechanisms remain unclear.This study was designed to explore an optimal protocol of PAS,which can modulate the excitability of MC in rats,and to investigate the underlying mechanisms. The resting motor thresholds (RMTs) of TMS-elicited motor evoked potentials (MEPs) recorded from the gastrocnemius muscle and the latency of P1 component of somatosensory evoked potentials (SEPs) induced by electrical tibial nerve stimulation were determined in male Sprague-Dawley rats (n=10).Sixty rats were then randomly divided into 3 groups:a PAS group (further divided into 10 subgroups at various ISIs calculated by using the latency of P1,n=5,respectively),a TMS (only)group (n=5)and a PNS (only)group (n=5).Ninety repetitions of PAS,TMS and PNS were administered to the rats in the 3 groups,respectively,at the frequency of 0.05 Hz and the intensity of TMS at 120% RMT and that of PNS at 6 mA.RMTs and motor evoked potentials'amplitude (MEPamp)were recorded before and immediately after the interventions.It was found that the MEPamp significantly decreased after PAS at ISI of 5 ms (P<0.05),while the MEPamp significantly increased after PAS at ISI of 15ms,as compared with those before the intervention (P<0.05).However,the RMT did not change significantly after PAS at ISI of 5 ms or 15 ms (P>0.05).PAS at other ISis as well as the sole use of TMS and PNS induced no remarkable changes in MEPamp and RMT.In conclusion,PAS can influence motor cortex excitability in rats.Neither TMS alone nor PNS alone shows significant effect.

Effects of cortical intermittent theta burst stimulation combined with precise root stimulation on motor function after spinal cord injury: a case series study

Activation and reconstruction of the spinal cord circuitry is important for improving motor function following spinal cord injury.We conducted a case series study to investigate motor function improvement in 14 patients with chronic spinal cord injury treated with 4 weeks of unilateral(right only)cortical intermittent theta burst stimulation combined with bilateral magnetic stimulation of L3-L4 nerve roots,five times a week.Bilateral resting motor evoked potential amplitude was increased,central motor conduction time on the side receiving cortical stimulation was significantly decreased,and lower extremity motor score,Berg balance score,spinal cord independence measure-III score,and 10 m-walking speed were all increased after treatment.Right resting motor evoked potential amplitude was positively correlated with lower extremity motor score after 4 weeks of treatment.These findings suggest that cortical intermittent theta burst stimulation combined with precise root stimulation can improve nerve conduction of the corticospinal tract and lower limb motor function recovery in patients with chronic spinal cord injury.

Corticospinal excitability during motor imagery is diminished by continuous repetition-induced fatigue

Application of continuous repetition of motor imagery can improve the performance of exercise tasks.However,there is a lack of more detailed neurophysiological evidence to support the formulation of clear standards for interventions using motor imagery.Moreover,identification of motor imagery intervention time is necessary because it exhibits possible central fatigue.Therefore,the purpose of this study was to elucidate the development of fatigue during continuous repetition of motor imagery through objective and subjective evaluation.The study involved two experiments.In experiment 1,14 healthy young volunteers were required to imagine grasping and lifting a 1.5-L plastic bottle using the whole hand.Each participant performed the motor imagery task 100 times under each condition with 48 hours interval between two conditions:500 mL or 1500 mL of water in the bottle during the demonstration phase.Mental fatigue and a decrease in pinch power appeared under the 1500-mL condition.There were changes in concentration ability or corticospinal excitability,as assessed by motor evoked potentials,between each set with continuous repetition of motor imagery also under the 1500-mL condition.Therefore,in experiment 2,12 healthy volunteers were required to perform the motor imagery task 200 times under the 1500-mL condition.Both concentration ability and corticospinal excitability decreased.This is the first study to show that continuous repetition of motor imagery can decrease corticospinal excitability in addition to producing mental fatigue.This study was approved by the Institutional Ethics Committee at the Nagasaki University Graduate School of Biomedical and Health Sciences(approval No.18121302)on January 30,2019.

Combining Motor Imagery and Action Observation with Vibratory Stimulation Increases Corticomotor Excitability in Healthy Young Adults

Vibratory stimulation but also motor imagery and action observation can induce corticomotor modulation, as a bottom-up stimulus and top-down stimuli, respectively. However, it remains unknown whether the combination of motor imagery, action observation, and vibratory stimulation can effectively increase corticomotor excitability. This study aimed to investigate the effect of motor imagery and/or action observation, in the presence or absence of vibratory stimulation, on the corticomotor excitability of healthy young adults. Vibratory stimulation was provided to the palm of the right hand. Action observation consisted in viewing a movie of someone else’s finger flexion and extension movements. The imagery condition required the participants to imagine they were moving their fingers while viewing the movie and attempting to move their fingers in accordance with the movie. Eleven right-handed healthy young adults were asked to perform six conditions randomly: 1) vibratory stimulation, imagery, and action observation, 2) vibratory stimulation and action observation, 3) vibratory stimulation and viewing of a blank screen, 4) imagery and action observation, 5) action observation, and 6) viewing of a blank screen. Single-pulse transcranial magnetic stimulation was conducted to assess corticomotor excitability and the peak-to-peak amplitude of the motor evoked potentials. The results showed that vibratory stimulation increases corticospinal excitability. The findings further revealed that performing motor imagery while viewing finger movement is more effective at inducing an augmentation of corticomotor excitability compared to action observation alone. Thus, the combination of motor imagery, action observation, and vibratory stimulation can effectively augment corticomotor excitability.

电针上肢穴位对运动皮层躯干脑区皮质脊髓兴奋性的影响

目的观察电针上肢穴位对健康受试者初级运动皮层(primary motor cortex,M1)躯干脑区皮质脊髓兴奋性的影响。方法纳入15名健康受试者,采用交叉设计。试验一观察电针上肢穴位对竖脊肌(erector spinae,ES)皮质脊髓兴奋性的影响,受试者随机先后进入3组试验,A组电针合谷穴,B组电针孔最穴,C组假针合谷穴。运用经颅磁刺激,检测干预前后对侧M1第一骨间背侧肌、桡侧腕屈肌及ES的运动诱发电位(motor evoked potentials,MEPs)的波幅和潜伏期,ES的MEPs波幅升高者进入试验二。试验二为抑制背侧前运动皮层(premotor cortex,PMd)后电针上肢穴位对ES的皮质脊髓兴奋性的作用研究,受试者随机先后进入两组试验,D组采用抑制PMd配合电针合谷穴干预,E组采用抑制PMd配合电针孔最穴干预。观察并比较两组对侧M1上肢脑区和躯干脑区MEPs的波幅和潜伏期。结果A组和B组干预后上肢脑区及躯干脑区MEPs总波幅均较同组干预前显著增加(P<0.001,P<0.01)。A组干预后上肢脑区及躯干脑区MEPs总波幅均明显高于C组,B组干预后仅躯干脑区MEPs总波幅明显高于C组,差异均具有统计学意义(P<0.001)。D组干预后上肢脑区最佳刺激点MEPs平均波幅及总波幅较同组干预前均显著增加(P<0.05)。D组和E组干预前后躯干脑区最佳刺激点的MEPs平均波幅及总波幅比较,差异也均无统计学意义(P>0.05)。结论生理状况下,电针合谷、孔最穴均可增强ES的皮质脊髓兴奋性,二者之间无明显差异,PMd可能参与其过程。

脑电振荡特征对经颅磁刺激运动诱发电位幅值影响的研究现状

介绍了大脑神经振荡状态对经颅磁刺激(transcranial magnetic stimulation,TMS)作用效果的影响,综述了TMS刺激初级运动皮层时α振荡功率、α振荡相位、β振荡功率及β振荡相位4种与运动功能密切相关的脑电(electroencephalogram,EEG)振荡特征与运动诱发电位(motor evoked potential,MEP)幅值之间关系的研究现状,分析了该领域研究存在的不足,为深入理解TMS效果差和不稳定的神经生理基础提供了参考。

小剂量利多卡因复合丙泊酚对颅内肿瘤切除老年病人运动诱发电位的影响

目的探讨小剂量利多卡因复合丙泊酚对老年颅内肿瘤切除术病人术中运动诱发电位(MEP)的影响。方法选择全麻下行颅内肿瘤切除的老年病人44例为研究对象,采用随机数表法将其分为利多卡因组(L组)和对照组(C组),每组22例。所有病人均给予丙泊酚麻醉处理,L组复合使用小剂量利多卡因,C组给予等量生理盐水,术中均行MEP监测。记录2组病人麻醉期间的平均动脉压(MAP)、心率(HR)、麻醉深度、MEP波幅和潜伏期、丙泊酚用量及不良反应发生情况。结果麻醉期间,C组不同时点HR及MAP存在明显波动,差异有统计学意义(P<0.05),L组HR及MAP未见明显波动(P>0.05);2组MEP波幅和潜伏期差异均无统计学意义(P>0.05),但L组丙泊酚用量及不良反应发生率明显低于C组(P<0.05)。结论小剂量利多卡因对颅内肿瘤老年手术病人MEP波幅和潜伏期均无显著影响,但有利于维持血流动力学稳定,减少术中丙泊酚用量,降低不良反应发生率。

耳甲电针对新型冠状病毒感染后睡眠障碍患者大脑皮质兴奋性的调节作用

目的:探讨耳甲电针对新型冠状病毒感染后睡眠障碍患者大脑皮质兴奋性的调节作用。方法:选取2022年6月至2023年6月广东省佛山市第八人民医院金沙分院中医科和康复科门诊失眠患者和健康志愿者各20例作为研究对象,采用匹兹堡睡眠质量指数(PSQI)量表和过度觉醒量表(HAS)来评估受试者的一般情况,同时利用单脉冲经颅磁刺激技术,采集2组受试者经耳甲电针治疗前后的皮层运动诱发电位相关指标,观察耳甲电针对皮层运动诱发电位潜伏期和波幅的调节作用。结果:治疗前观察组与对照组比较,患者的皮层运动诱发电位潜伏期短,波幅大;治疗后,患者的皮层运动诱发电位潜伏期未见显著变化,但波幅有所下降。结论:耳甲电针可以通过激活自主神经系统,调节大脑皮质兴奋性,从而抑制新型冠状病毒感染后睡眠障碍患者大脑皮质过度觉醒状态,可能是耳甲电针治疗失眠的机制之一。

运动神经元病和帕金森病的经颅磁刺激运动诱发电位分析与疾病分型和病程的相关性研究

目的探讨运动神经元病和帕金森病的经颅磁刺激运动诱发电位(TMS-MEP),分析与疾病分型和病程的相关性。方法共收集2020年7月至2024年3月在安徽中医药大学神经病学研究所附属医院住院的运动神经元病(MND)患者20例(MND组),帕金森病(PD)患者12例(PD组),以及同期健康体检者10名(正常对照组),均行经颅磁刺激TMS-MEP检查,并收集临床资料。比较3组受试者MEP波幅、MEP潜伏期以及MEP波形参数,采用Pearson相关性分析MEP波幅、MEP潜伏期参数与病程的相关性。结果肌萎缩侧索硬化(ALS)患者首发症状以上肢无力、下肢无力为主,而PD患者首发症状以上肢、下肢抖动僵硬为主。ALS组、PD组、对照组的MEP潜伏期、MEP波幅差异有统计学意义,其中PD组MEP潜伏期相较对照组无差异(P>0.05),而明显低于ALS组(P<0.05)。PD组MEP波幅低于对照组,高于对ALS组(P<0.05)。ALS和PD患者的MEP波形存在差异(P<0.05),其中ALS组患者以2级为主,而PD患者以1级为主。Pearson相关性分析显示,ALS患者MEP潜伏期与病程呈正相关性(r=0.539,P<0.05),PD患者MEP波幅与病程呈负相关性(r=-0.438,P<0.05)。结论TMS-MEP检查可有效评估PD、ALS。ALS患者MEP潜伏期明显增加,波幅明显减低,病程越长则MEP潜伏期越长;PD患者MEP潜伏期较健康人群无明显变化,而波幅略有降低,病程越长MEP波幅降低越明显。

脑梗死患者经颅磁刺激运动诱发电位的特点及临床意义

目的探讨脑梗死患者经颅磁刺激运动诱发电位(MEP)变化特点及与病情严重程度、预后之间的相关性。方法选择31例单侧大脑半球脑梗死患者为疾病组,50名健康者为对照组,均行MEP检查。观察两组第7颈椎棘突旁大鱼际肌、第4腰椎棘突旁胫前肌、皮质手区及皮质脚区潜伏期和中枢运动传导时间(CMCT)的变化;分析疾病组患侧皮质潜伏期和CMCT与神经功能缺损评分(改良爱丁堡斯堪的纳维亚量表,MESSS)及日常生活能力评分(Barthel指数,BI)的相关性。结果疾病组患侧上肢皮质手区潜伏期及CMCT分别为(24.7±2.8)ms、(11.1±2.7)ms;健侧为(22.8±2.5)ms、(7.9±2.0)ms;对照组为(22.4±3.2)ms、(7.6±1.3)ms。下肢皮质腿区潜伏期及CMCT分别为(31.7±3.7)ms、(17.6±4.8)ms;健侧为(29.6±3.1)ms、(15.3±3.1)ms;对照组为(29.4±3.4)ms、(15.2±3.6)ms。疾病组患侧的皮质潜伏期和CMCT与对照组及健侧比较,差异均具有显著意义(P<0.01,P<0.05)。脑梗死患者患侧皮质潜伏期和CMCT与MESSS呈正相关,与BI呈负相关。结论MEP可客观地反映脑梗死患者运动功能缺失的情况,并具有一定的病情判断和预后评估的价值。

高频重复经颅磁刺激对脑梗死大鼠运动诱发电位皮质潜伏时和中枢运动传导时间的影响

目的:观察不同刺激强度的高频重复经颅磁刺激(rTMS)对脑梗死大鼠运动诱发电位(MEP)的影响。方法:43只大鼠随机分为正常组、模型组、假刺激组、rTMS组(按不同刺激强度分80%MT亚组、100%MT亚组、120%MT亚组)。测定运动阈值(MT)后制备大脑中动脉栓塞模型。模型成功24h后给予20Hz,刺激时间2s,间隔时间28s,总脉冲数为1200的rTMS刺激,连续刺激14d。观察术前、术后1d、治疗7d和治疗14d时双侧中枢传导时间(CMCT)和皮质潜伏时(CL)的变化。结果:①术前各组左右侧CMCT、CL的比较差异均无显著性意义(P>0.05)。②术后1d左侧CMCT、CL较术前和右侧缩短(P<0.01)。③治疗7d时,双侧CMCT、CL各组之间以及各组双侧CMCT、CL比较差异均无显著性意义(P>0.05)。④治疗14d时,100%MT亚组左侧CMCT、CL较正常组和治疗7d时均缩短(P<0.05),双侧CMCT、CL均较术前缩短(左侧P<0.01,右侧P<0.05);80%MT亚组右侧CMCT、CL较术后1d缩短(P<0.05)。结论:本实验结果提示20HzrTMS有助于促进脑梗死大鼠双侧CMCT和CL缩短使双侧大脑达到某种平衡或者代偿,80%MT和100%MT两种强度的rTMS作用可能较大。

麻醉深度与肌松程度对运动诱发电位影响的比较

目的 比较麻醉深度和神经肌肉阻滞程度对经颅磁刺激运动诱发电位 (tcMMEPs)的影响。方法 2 5例择期行脊髓手术的病人 ,分别在清醒时及BIS值为 75～ 6 5、6 5～ 5 5和 5 0～ 30时记录tcMMEPs的波形 ;维持肌松使 4个成串刺激的第一个刺激T1在 5 0 %左右 ,重复上述实验。结果 (1)在没有神经肌肉阻滞时 ,麻醉后tcMMEPs的波幅在各BIS值范围内与清醒时相比均显著减小 (P <0 0 0 1) ,但随后并不随着麻醉的继续加深而下降 (P >0 0 5 ) ,只有当BIS值达到 5 0～ 30的范围时其波幅与BIS值在 75～ 6 5时相比才有显著下降 (P <0 0 0 1)。 (2 )当T1在 5 0 %左右时 ,各BIS值范围内的波幅与清醒时相比均有非常显著差异 (P <0 0 0 1) ,且每个BIS范围内的数值与同组T1为 10 0 %时相比均有显著性差异 (P <0 0 0 1) ,而各BIS范围之间的波幅无显著性差异 (P >0 0 5 )。