脑血管病患者H反射和F波随刺激增强的特征表现

脑血管病偏瘫患者的H反射可由超强刺激所诱发。本实验对 31例患者在放松状态用增强刺激检测了患臂的H反射和F波 ,研究H反射和F波随刺激增强的特征表现与临床神经体征的关系 ,结果提示H反射和F波的表现特征受神经体征严重程度的影响。     

大鼠后肢肌电图H反射和F波的研究

为探讨正常大鼠后肢肌电图H反射和F波的测定方法及其波型特点,采用两种不同的方式（显露与不显露坐骨神经）对大鼠双侧后肢腓肠肌进行诱发肌电图检查,观察波型特点．测定其潜伏时及振幅,并进行比较。结果：两种方法均可引出H反射和F波,H波为单相或二捆波,其潜伏时为6．6±0．5ms,最大振幅3．9±0．4mV;F波为单相波．潜伏时为6．4±0．6ms,振幅为1．0±0．2mV。手术显露坐骨神经后测定H反射和F波成功率高．稳定性好,干扰较小。提示夭鼠后肢可引出与人类类似的H反射和F波,显露坐骨神经后进行测定效果较好。     

糖尿病患者神经传导速度及H反射和F波检测结果分析

目的:探讨糖尿病患者近端神经及周围神经病变的发生频度.方法:我院2005年8月～2007年8月对90例糖尿病(糖尿病组)肢体神经共635条及30例健康人(对照组)肢体神经180条,采用牛津Medeiec Synergy肌电诱发电位仪,检测内踝胫神经、腕正中神经,刺激足拇短屈肌、手拇短展肌记录M波,拇短展肌记录F波,比目鱼肌记录H反射的H波.用多元回归进行对照分析.结果:糖尿病组往返脊髓传导速度异常率61.4%,神经运动传导速度异常率50.1%,神经感觉传导速度异常率43.4%,神经传导速度异常率80.0%,F波出现异常率60.6%,F波潜伏期异常率76.0%,H波异常率78.9%,H反射潜伏期异常率54.3%,H波波幅降低63.0%,M/H比值异常54.2%,与对照组比较差异具有非常显著统计学意义(P<0.01).结论:糖尿病神经病变为广泛多发性周围神经远端病变,并常累及神经近端,特别是周围神经运动传导速度及H波的异常,是神经病变早期最灵敏的信号.     

磁刺激H反射结合F波测定对骶1感觉神经根病变的诊断价值

目的通过磁刺激骶1（S1）神经根引出H反射并结合F波测定评估腰骶神经根病患者的感觉神经根功能。 方法检测30名健康受试者和30名单侧S1神经根受损的患者，在双侧比目鱼肌分别记录磁刺激骶1神经根引出的H反射和电刺激腘窝处胫神经引出的F波，同时记录各自的M波，计算感觉神经根传导时间（SRCT），并分析正常人SRCT与身高、年龄的关系及其与疼痛程度的相关性。 结果正常组的平均SRCT为(3.10±0.44)ms，侧间差为(0.13±0.19)ms；病例组平均SRCT及侧间差分别为(3.90±0.65)ms和(0.90±0.50)ms,均较正常组显著延长（P<0.01）。所检正常人的SRCT与身高相关，与年龄无明显相关性。病例组的SRCT与疼痛程度呈正相关，但相关系数较低。 结论SRCT可作为评价感觉神经根功能的一项指标，为骶1神经根病的无创性电诊断提供了一个新的方法。     

脊髓损伤患者下肢胫神经H反射和F波的临床观察

目的：观察脊髓损伤(SCI)患者不同时期下肢胫神经H反射和F波的变化与临床神经体征之问的关系及电生理评定方面的意义。方法：对同一时期在我科住院的24例SCI患者进行双下肢胫神经H反射和F波检查．同时采用Ashworth痉挛评定方法评定及记录患肢肌张力、腱反射等。观察H反射和F波的特征表现与临床体征之间的关系。结果：SCI患者临床不同时期，下肢H反射和F波的表现不同．H反射和F波的表现特征受神经体征严重程度的影响。结论：H反射和F波有可能做为临床评定痉挛的客观电生理指标，它优于主观的Ashworth等痉挛评定方法．但尚需通过临床观察来完善这一指标的评定标准。     

胫前肌腓骨长肌改良H反射的正常值及对L5神经根受压的临床应用

54名健康受试者接受H反射检查,胫前肌、腓骨长肌静息时刺激腓总神经,有12名可引出微弱的H反射.改良H反射是指测试肌收缩时所进行的测试,所有受试者都可记录到H反射波.足背屈时可增强庄前肌的H反射,跖屈时减弱;腓骨长肌H反射与之相反.H反射幅度在同一受试者双侧或不同受试者之间差异显著.改良H反射应用于16例L_5神经根受压患者,其中13例发现异常,表现为:双侧潜伏时差超过正常范围,单侧或双侧潜伏时延长,反射减弱或消失.实验表明改良H反射对脊神经根损伤的功能完整性评价是一项重要可靠的试验.     

H反射在脑卒中后上肢偏瘫患者中的特征表现及分析

目的:通过研究脑卒中后上肢偏瘫患者H反射的特征表现,及其与偏瘫肢体肌张力的关系,探讨H反射在脑卒中后上肢偏瘫患者神经电生理评定中的应用价值。方法:选择符合本研究入选标准的脑卒中恢复期偏瘫患者42例。分别对患者双侧正中神经、尺神经、桡神经所支配的拇短展肌、小指展肌、指总伸肌进行H反射检查,并对患侧上肢给予改良Ashworth痉挛量表(MAS)评定,确定上述神经中哪些更容易引出H反射,并对其所引出的H反射结果及其与MAS的相关性进行比较和分析。结果:患者双侧正中神经、尺神经所支配的拇短展肌、小指展肌均较易引出H反射,引出率100%。桡神经所支配的指总伸肌不易(3例/42例,引出率7.14%)引出H反射。患侧正中神经和尺神经的H反射潜伏期分别为(25.89±3.66)ms、(25.71±3.26)ms;健侧正中神经和尺神经的H反射潜伏期分别为(26.60±3.11)ms、(26.44±2.87)ms。配对t检验分析,差异均有显著性意义(P<0.05);Hmax/Mmax比值均数用中位数表示,患侧正中神经和尺神经的Hmax/Mmax比值分别为0.185和0.217;健侧Hmax/Mmax比值分别为0.126和0.112,用Wilcoxon符号秩检验分析,患侧与健侧差异均有显著性意义(P<0.05)。用Kruskal-WallisH检验分析显示:患侧上肢正中神经、尺神经H反射潜伏期在MAS不同级别中没有差异,而Hmax/Mmax比值在MAS不同级别中有差异。Spearman秩相关检验结果显示:患侧上肢正中神经H反射潜伏期、Hmax/Mmax比值以及尺神经H反射潜伏期与MAS不相关;而患侧上肢尺神经Hmax/Mmax比值与MAS存在秩相关关系。结论:上肢H反射与MAS存在一定关系,其中Hmax/Mmax比值是评估下运动神经元兴奋性的较好指标,可以成为临床评价痉挛的客观神经电生理指标。     

健康人群肌肉电刺激前后比目鱼肌M波和H-反射

目的:探讨健康人群肌肉电刺激(EMS)前后比目鱼肌M波和H-反射的变化。方法:对5名健康人予EMS诱发肌肉疲劳,记录刺激前后右侧比目鱼肌最大M波及H/M波幅。结果:最大M波刺激后显著降低,H/M波幅变化不一致。结论:EMS可诱发肌肉疲劳,但与疲劳比目鱼肌相关联的脊髓神经兴奋性未出现一致改变。     

F波在Bell面瘫时的应用

<正> F 波是逆向激活运动神经后的迟发反应。F 波记录在诊断周围和中枢神经系统疾病中十分有用,因而在电诊断研究中受到愈来愈多的注意。在1950年Magladery 与McDougalt 刺激尺神经时在小鱼际肌群记录到主要运动激发反应后面另有一个电位,称之为F 波,以区别于具有相似潜伏时的H 反射。常用的神经传导研究只能检查周围神经的远段,而F 波则可用以确定神经近体段的潜伏时。据报导,在Charcot-Marie-Tooth,Guil-     

三叉神经-颈反射在多发性硬化中的诊断价值

目的 建立三叉神经-颈反射(TCR)的肌电检测方法，探讨其在多发性硬化中的诊断价值。方法受检测者取仰卧位，头部轻度抬高。刺激一侧眶下神经，于双侧胸锁乳突肌记录。结果刺激对照者一侧的眶下神经，可于双侧胸锁乳突肌引出正／负波。多发性硬化病人波形正常者8例(26.7％)，潜伏期延长者8例(26.7％)，双侧反射的超常不对称者14例(46．7％)。结论 TCR能够可靠测定，可作为多发性硬化的一种辅助检查手段。     

重复经颅磁刺激对不完全性脊髓损伤患者痉挛的影响

目的:观察高频重复经颅磁刺激(rTMS)对不完全性脊髓损伤(SCI)患者双下肢痉挛的影响。方法:对18例不完全性SCI患者作为SCI组,另取7例健康正常人作为正常组。给予SCI组进行rTMS治疗,采用"8"字形线圈rTMS刺激不完全性SCI患者(M1区),刺激强度为90%的RMT,刺激频率10Hz,共4周。观察其对患者下肢改良Ashworth痉挛评分(MAS)的影响,同时观察rTMS刺激治疗前后患者下肢F波的出现率、潜伏时(F-lat)、H反射潜伏时(H-lat)、H反射以及M波最大波幅比值(Hmax/Mmax值)等电生理指标的变化,同时与正常组做比较。结果:治疗后,SCI组下肢MAS分级较治疗前明显改善(P0.05);SCI组治疗前F波和H反射潜伏时较正常组明显延长(P0.05),Hmax/Mmax值较正常组增高(P0.05);治疗后F波的平均潜伏时较治疗前减少(P0.05),H反射潜伏时无显著差异,Hmax/Mmax值降低(P0.05);SCI组F波出现率在治疗前后无差异性变化,Hmax/Mmax值和MAS之间无明显相关性。结论:rTMS治疗前后SCI患者的电生理和MAS指标变化,提示高频rTMS对治疗不完全性脊髓损伤患者下肢痉挛有一定的缓解作用,值得进一步的研究。     

Electrophysiological evaluation of the patient with acute spinal cord injury

This article reviews basic principles, equipment and techniques, and clinical applications of electrophysiologic monitoring in patients with spinal cord injuries. Four groups of electrophysiologic measurements are considered: Somatosensory evoked potentials (SEPs); motor evoked potentials (MEPs); electromyography (EMG) and nerve conduction studies; and late responses, including H reflex, M response, and F wave. Reports of SEP recordings in spinal cord injury, as drawn from the literature, are tabulated in detail.     

Synchronous stimulation and monitoring of soleus H reflex during robotic body weight-supported ambulation in subjects with spinal cord injury

We evaluated the accuracy of a novel method for recording the soleus H reflex at specific points in the gait cycle during robotic locomotor training in subjects with spinal cord injury (SCI). Hip goniometric information from the Lokomat system defined midstance and midswing points within the gait cycle. Soleus H reflex stimulation was synchronized to these points during robotic-assisted ambulation at 1.8 and 2.5 km/h. Motor stimulus intensity was monitored and adjusted in real time. Analysis of 50 H reflex cycles during each speed and gait phase showed that stimulation accuracy was within 0.5 degrees of the defined hip joint position and that >85% of the H reflex cycles met the +/-10% M wave criterion that was established during quiet standing. This method allows increased consistency of afferent information into the segmental spinal and supraspinal circuitry and, thus, evaluation of H reflex characteristics during robotic ambulation in subjects with SCI.     

H reflex and F wave latencies to soleus normal values and side-to-side differences.

OBJECTIVE: Electromyographers must reliably differentiate between H reflexes and F waves when recording from the soleus muscle in the evaluation of S1 radiculopathy. The use of F waves in root-level injuries is questioned, whereas H reflexes have shown value in the evaluation of S1 radiculopathy. We studied the relationship between the tibial H reflex and F wave latencies in the limbs of 40 subjects. DESIGN: After recording the H wave latency, we changed the gain to 200 microV/cm and increased the stimulation to supramaximal for ten additional responses without moving the recording or stimulating electrodes. We also calculated the predicted H wave latency with the standard formula. Forty subjects, mean age 32 yr, consented and participated. RESULTS: The mean of the average F wave was 1.76 ms longer than the ipsilateral H reflex latency. The mean side-to-side difference of the average F wave was 0.56 ms. The H reflex latency side-to-side difference was 0.36 ms. CONCLUSION: The findings suggest that the average F wave latencies have a predictive value in the clinical context similar to the H reflex.     

Cannabinoid‐induced effects on the nociceptive system: A neurophysiological study in patients with secondary progressive multiple sclerosis

Although clinical studies show that cannabinoids improve central pain in patients with multiple sclerosis (MS) neurophysiological studies are lacking to investigate whether they also suppress these patients’ electrophysiological responses to noxious stimulation. The flexion reflex (FR) in humans is a widely used technique for assessing the pain threshold and for studying spinal and supraspinal pain pathways and the neurotransmitter system involved in pain control. In a randomized, double‐blind, placebo‐controlled, cross‐over study we investigated cannabinoid‐induced changes in RIII reflex variables (threshold, latency and area) in a group of 18 patients with secondary progressive MS. To investigate whether cannabinoids act indirectly on the nociceptive reflex by modulating lower motoneuron excitability we also evaluated the H‐reflex size after tibial nerve stimulation and calculated the H wave/M wave (H/M) ratio. Of the 18 patients recruited and randomized 17 completed the study. After patients used a commercial delta‐9‐tetrahydrocannabinol (THC) and cannabidiol mixture as an oromucosal spray the RIII reflex threshold increased and RIII reflex area decreased. The visual analogue scale score for pain also decreased, though not significantly. Conversely, the H/M ratio measured before patients received cannabinoids remained unchanged after therapy. In conclusion, the cannabinoid‐induced changes in the RIII reflex threshold and area in patients with MS provide objective neurophysiological evidence that cannabinoids modulate the nociceptive system in patients with MS.     

强迫症和精神分裂症患者的听及视信息加工过程中感觉性脑诱发电位特征比较

背景应用脑诱发电位技术比较强迫症和精神分裂症患者在听及视信息加工过程中感觉性脑诱发电位特征,是否可发现一些异常的生物学指标.目的观察强迫症和精神分裂症患者感觉性脑诱发电位长潜伏期及听觉脑诱发电位的变化特征,并与健康人相比较.设计随机抽样法,病例对照研究.地点和对象病例组为宁波市康宁医院门诊和住院患者,对照组均为身心健康的志愿者.干预利用意大利百胜公司GalileoSirius电生理仪对36例强迫症和36例精神分裂症患者用33例正常对照组进行了短声、闪光刺激,完成听觉脑诱发电位、视觉脑诱发电位.主要观察指标观察主波出现率,各波的波幅和潜伏期.结果发现与正常对照组相比,强迫症和精神分裂症患者无论在听觉诱发电位(auditory evoked potentials AEP),还是在视觉诱发电位(vi-sual evoked potentials VEP)中,其P3波出现率明显减少(x2=12.73,P＜0.01;x2=13.13,P＜0.01);其中VEP/P3出现率精神分裂症与强迫症相比更为减少(x2=34.62,P＜0.01).强迫症和精神分裂症患者的AEP/P2波呈双峰率现象均增高(x2=4.17,P＜0.05).强迫症、精神分裂症和正常对照组三组在相比,在AEP中潜伏期N1、P2波延长(F=6.95,P＜0.01;F=6.45,P＜0.01),波幅N1波下降(F=3.55,P＜0.05);VEP中P2潜伏期延长(F=6.16,P＜0.01),波幅P2,P3波均有改变(F=7.96,P＜0.01;F=12.06,P＜001).结论强迫症和精神分裂症患者在听、视信息加工过程均有不同程度的异常,以精神分裂症为重,其异常指标与其发病机制和症状有关,值得关注.     

Electrically evoked itch in humans

We compared itch sensations and axon reflex flare induced by transcutaneous electrical (0.08-8 ms, 2-200 Hz) and chemical (histamine iontophoresis; 100 microC) stimulation. Stimuli were applied to non-lesional volar wrist skin in 20 healthy human subjects and 10 patients with atopic dermatitis. Intensity of evoked itch and pain sensations were rated on a numerical rating scale (NRS) of 0 (no sensation) to 10 (the maximum sensation imaginable). The axon reflex erythema was measured by laser Doppler imager and areas of alloknesis (itch evoked by light brushing) and hyperknesis (itch evoked by pricking) were assessed psychophysically. Electrical stimulation was most effective for stimulus durations >or=2 ms and frequencies >or=50 Hz. It evoked pure itch as threshold sensation in 80% of the subjects that was perceived with a delay of approximately 1 s. Itch intensities of up to 7/10 were not accompanied by an axon reflex flare. In contrast, histamine provoked a massive increase of axon reflex erythema and maximum itch ratings of 3.1+/-0.2. The extention of alloknesis areas (2.3+/-0.5 cm) evoked by electrical stimulation clearly exceeded those induced by histamine (0.7+/-0.3 cm). Healthy subjects and patients with atopic dermatitis did not differ significantly in their response to either stimulation. We conclude that C-fiber activation underlies the electrically evoked itch sensation. The low electrical thresholds and the absence of an axon reflex flare suggest that these fibers are not identical with the previously described mechano-insensitive histamine responsive C fibers, but represent a separate peripheral neuronal system for the induction of itch.     

The effect of multiple stimuli on the modulation of the 'nociceptive' blink reflex

The 'nociceptive' blink reflex is a method of examining human trigeminal pain pathways. We explored temporal summation of this reflex by using a train of pulses, rather than a single pulse, and remote activation of diffuse noxious inhibitory control (DNIC), to improve reliability, flexibility and nociceptive specificity of this technique. The R2 component of the nociceptive blink reflex response (nR2) was assessed in 28 healthy volunteers using between 1 and 7 pulses per stimulus train (inter-pulse interval 5 ms). The effect of DNIC on single-, double-, and triple-pulse nR2 was investigated. Compared to single pulses, double and triple pulses increased the sensation of pain, reduced the tactile and pain thresholds, and facilitated the blink reflex responses (reduced onset latency, increased magnitude and persistence of nR2). The maximal reflex facilitation was achieved using a triple pulse. Higher pulse numbers had no additional facilitatory effect. Activation of the DNIC system using heterotopic pain suppressed the nR2 evoked by double and triple stimulation by 16 and 42%, respectively, but not the nR2 from a single pulse. Stimulation with double and triple pulses may be more suitable to study influences on nociceptive pathways than single pulses and may widen the methodological flexibility of the nociceptive blink reflex technique. This technique may be useful in studying the trigeminal nociceptive system with particular reference to primary headache disorders and their neuropharmacology.     

Laser evoked potentials and prepulse inhibition of the blink reflex in patients with Wallenberg's syndrome

Spinothalamic tract lesions in patients with Wallenberg's syndrome can be demonstrated by abnormalities in the laser evoked potentials (LEPs) to stimulation of the affected side. However, before reaching the structures generating LEPs, laser stimuli can induce effects at a subcortical level. We examined LEPs and laser-induced prepulse inhibition of the blink reflex in seven patients with Wallenberg's syndrome within a month after the infarct. All patients had abnormally elevated thresholds for temperature and pain sensation, and for pinprick pain induced by laser stimuli, in the affected vs the non-affected side. LEPs to stimulation of the affected side were abnormal because of absent, reduced or delayed responses. However, the same laser stimuli that were unable to induce LEPs generated normal inhibition of the blink reflex response when applied 250ms before a trigeminal nerve electrical stimulus. The percentage inhibition induced in the R2 response of the blink reflex by laser stimulation of the affected side was not different from that induced by stimulation of the non-affected side, or in control subjects. These results are compatible with either a different pathway for prepulse inhibition and evoked potentials or a reduced energy requirement of the sensory input generating prepulse inhibition in comparison to that generating evoked potentials.     

Local electrical stimulation: Effective needling points for suppressing jaw opening reflex in rat

Effects of electroacupuncture on the jaw opening reflex after tooth pulp stimulation were investigated in lightly anesthetized rats. Electroacupuncture stimulation (45 Hz, 5 msec) was delivered to 8 meridian points and 6 nonmeridian ones for 15 min so as to compare the degree of suppression elicited from each point. Significant suppressive effects on the reflex were observed in the cases of Yin-Hsiang, Ho-Ku and Shou-Sanli stimulation and these effects were antagonized by naloxone. However, stimulation of Hsia-Kuan, Chu-Chih, Neiting and Taichi, although these points were reported to suppress oro-facial or dental pain in man, scarcely produced suppressive effects. On the other hand, stimulation of some nonmeridian points produced moderate analgesic effects as gauged by the jaw opening reflex. The present study revealed that specificity of the meridian points is not absolute, but relative and that Yin-Hsiang, Ho-Ku and Shou-Sanli points were fairly effective in suppressing pulp-evoked jaw opening reflex in rat, which is presumably a noxious reflex. When the jaw opening reflex was evoked by non-pulpal stimulation, electroacupuncture was less effective on the reflex.