以强直症状为主的帕金森病患者的F波研究

目的 :研究以强直症状为主的帕金森病 (PD)患者脊髓α运动神经元的兴奋性是否增高。方法 :选取一组以强直症状为主的PD患者与一组年龄、性别匹配的正常人作对照研究 ,分别测定其静息、易化状态时的F波 ,并进行比较。结果 :以强直症状为主的帕金森病患者F波多项参数增加 ,易化现象明显受损。结论 :以强直症状为主的帕金森病患者脊髓α运动神经元的兴奋性有增高     

The utility of F wave chronodispersion in lumbosacral radiculopathy

The sensitivity of F wave chronodispersion (Fc) in evaluating nerve root pathology is unknown. We compared Fc in 91 patients with clinical and EMG evidence of L5 or S1 radiculopathy with Fc in 81 controls in order to evaluate its sensitivity in lumbosacral radiculopathy. F waves were obtained by stimulating the peroneal and tibial nerves behind the knee and recording from the extensor digitorum brevis (L5 predominant) and flexor hallucis brevis (S1 predominant) muscles, respectively. Fc was calculated by subtracting the shortest F wave latency from the longest and, in controls, ranged from 0.2 to 23.4 ms in the peroneal nerve, and from 1.2 to 13.4 ms in the tibial nerve (95th percentile = 13 ms for the peroneal nerve and 9.2 ms for the tibial nerve). In the patient group, Fc also ranged from 0.2 to 23.4 ms in the peroneal nerve, and from 0.4 to 18.2 ms in the tibial nerve. Only 5 (5.5%) and 8 (11.3%) patients for the peroneal and tibial nerves, respectively, had Fc values which fell beyond the 95th percentile, a percentage far below the sensitivity of F wave latency measurement and not substantially different from chance. Thus we conclude that Fc has no substantial additional value in evaluating lumbosacral radiculopathy over that of F wave latency.     

Subtypes of carpal tunnel syndrome: median nerve F wave parameters

The carpal tunnel syndrome (CTS) provides a model for analyzing the effects of focal nerve injury on F waves. We studied 127 patients (164 CTS) with clinical and electrophysiological CTS and 35 healthy controls in order to determine the alteration of F wave parameters in different types of CTS and to evaluate the most predictive F wave abnormality for each type. Minimal, maximal and mean F wave latencies, F wave persistence and chronodispersion recorded from abductor pollicis brevis (APB) muscle with wrist stimulation were compared. Twenty-three patients (29 CTS) had prominent demyelinating type CTS, 37 patients (45 CTS) had prominent axonal type CTS and 60 patients (90 CTS) slight demyelinating CTS according to electrophysiological parameters. The amplitude of APB muscle and F wave persistence were correlated significantly (r: 0.36, P<0.001). Minimal F wave latency was more prolonged in demyelinating group than in the axonal and slight demyelinating groups (P=0.001). In conclusion, F wave determination, as a simple and valuable method, allows the discrimination between demyelinating injury and axonal degeneration and increases the diagnostic yield in CTS.     

脑卒中患者双上肢F波的变化及其评价肢体痉挛的可靠性

目的观察脑卒中患者双上肢正中神经F波的变化特征及其与患侧上肢肌张力的关系,探讨F波在脑卒中患者上肢痉挛评价中的应用价值。方法选取2014-7—2015-7作者医院神经内科收治的脑卒中患者40例(脑卒中组),其中男24例、女16例;选取30名健康者作为正常对照组,其中男18名,女12名。应用丹麦丹迪公司生产的Keypoint.net肌电/诱发电位仪进行F波测定,对脑卒中组患者患侧、健侧及正常对照组F波的潜伏期、出现率、传导速度、波幅及面积进行比较。对脑卒中组患侧上肢进行改良Ashworth评分(MAS),并与F波部分参数进行Spearman相关性分析。结果 (1)脑卒中组患侧、健侧与正常对照组间F波潜伏期、传导速度、波幅及面积比较差异均有统计学意义(P0.05,P0.01),F波出现率比较差异无统计学意义(P0.05);(2)脑卒中组患侧F波传导速度较健侧减慢(P0.01),波幅增高(P0.01),面积增大(P0.01),而F波潜伏期与出现率变化无统计学差异(P0.05);(3)脑卒中患者患侧潜伏期较正常对照组延长(P0.01),传导速度减慢(P0.01),而健侧潜伏期及传导速度与正常对照组间比较差异均无统计学意义(P0.05);(4)脑卒中患者患侧F波波幅与腕及四指MAS评分均呈正相关(r=0.906,P0.01;r=0.685,P0.01),F波面积与腕及四指MAS评分均呈正相关(r=0.917,P0.01;r=0.669,P0.01),F波传导速度与四指MAS评分呈负相关(r=-0.524,P0.05)。结论脑卒中患者患侧上肢F波波幅及面积分别与MAS评分存在正相关,F波传导速度与四指MAS评分存在负相关,F波的传导速度、波幅及面积可作为脑卒中患者上肢痉挛程度评价客观的电生理指标。     

Analysis of F response in upper motoneurone lesions

The F response can provide a measure of motoneurone excitability (MNE) and so it may be used to investigate upper motoneurone disorders. This report studies the F-wave configuration in patients with stroke to evaluate the changes of the central excitability of the motoneurones at different times after an acute cerebral insult. Various parameters of the F response, including amplitude (absolute and F%/M), duration, and persistence have been determined in 26 patients with unilateral hemiplegia and in 32 healthy subjects of both sexes in the same age range. The investigation was carried out applying a series of 20 supramaximal stimuli at 0.5 Hz on tibial and ulnar nerves bilaterally. In all patients a detailed clinical examination and a CT scan were performed. Our results indicate that an initial stage of reduced spinal motoneuron excitability evidenced by a decreased F amplitude and persistence was present in the early phases after a stroke, followed within 90 days by an enhanced MNE. Moreover, F-wave amplitude shows a positive correlation with weakness and increased tone.     

F波在糖尿病周围神经病中的诊断价值

目的探讨F波在糖尿病周围神经病(DPN)中的诊断价值。方法收集作者医院的糖尿病患者100例,根据有无周围神经病变临床和体征分为临床DPN组(60例)和亚临床DPN组(40例),另选健康对照组50名。采用肌电图诱发电位仪检测各组F波最短潜伏期(Flmi)、F波潜伏期离散度(Fchd)、F比值(Fratio)、F波出现率(Fpresent)、F波波幅(Famp),并进行比较。结果 100例糖尿病患者中F波未引出2例(2%),F波Flmi延长33例(33%),临床DPN组Flmi异常率(41.7%)高于亚临床DPN组(20.0%)(P<0.05)。与对照组比较,临床DPN组和亚临床DPN组Fchd升高(P<0.05),Famp和Fpresent均降低(P<0.05)。临床DPN组与亚临床DPN组比较Fchd、Famp无统计学差异(P>0.05),而临床DPN组Fpresent较亚临床DPN组低(P<0.05),3组间Fratio比较无统计学差异(P>0.05)。F波各参数总异常率与尺神经运动传导各参数总异常率无统计学差异。结论 F波多个参数的测定有助于DPN的早期诊断,并有助于揭示亚临床病灶。     

Assessment of motor neuron excitability in parkinsonian rigidity by the F wave

Summary F-wave responses from abductor pollicis brevis muscle occurred more frequently, with a larger amplitude and longer duration in rigid parkinsonian patients than in age-matched normal controls. F-wave potentiation during voluntary contraction was impaired in parkinsonian patients. These findings suggest that spinal motor neuron excitability is enhanced in rigidity. F-wave amplitude was significantly correlated to the clinical evaluation of motor disability, so that the F wave may be regarded as a useful approach to quantitative evaluation of rigidity.     

F波在糖尿病性周围神经病中的诊断价值

目的 探讨F波在糖尿病性周围神经病（DPN）中的诊断价值。方法 测定106例糖尿病患者和75名正常人的下肢F波最短潜伏期、时限、波幅和面积，以及M波波幅和面积。结果 （1）无周围神经病变的糖尿病患者30例，F波时限增宽8例，F波最短潜伏期延长4例，F/M波面积增大2例。（2）有周围神经病变的糖尿病患者76例，F波最短潜伏期均延长；F/M波波幅和F/M波面积均增大；F波时限在轻型DPN患者中增宽，在重型DPN患者中未见明显异常。（3）正常人F波最短潜伏期上限（Y）与腿长（X）的函数关系为Y=12.3 48.8X^2。结论 （1）F波作为早期诊断DPN的敏感指标，并可发现亚临床DPN。（2）在DPN患者中，远端神经节段尚未发生病变时，即可出现近端神经节段病变，提示血管因素在DPN发病机制中的作用。     

F wave to height or limb length ratios as rational alternatives for F wave latency in clinical electrodiagnostic medicine

Objective

To delineate the F wave latency/height (Fmin/He) or F wave latency/limb length (Fmin/L) ratio as a more useful alternative for the currently reported shortest latency in milliseconds.

Methods

One hundred and sixty-six healthy volunteers, 85 upper limbs and 84 lower limbs entered the study. Minimum F wave latencies were determined in median, ulnar, tibial and peroneal nerves. The Fmin/He and Fmin/L ratios of each nerve were calculated.

Results

F latencies of all nerves had significant correlation with height and limb length but there was no correlation between either Fmin/He or Fmin/L and height in any nerve except for peroneal Fmin/He (p = 0.04, r = 0.23).

Conclusions

Using the Fmin/He or Fmin/L ratios are more accurate than reporting only the F wave minimum latency, since these ratios incorporate corrections for height and/or limb length. This method also eliminates the false positive and negative reports caused by using a single reference table for all heights.

Significance

A unique reference table can be produced using the Fmin/He or Fmin/L for all populations and races, so that the comparison between different population samples can be done easily. Also data of different investigations can be pooled together for meta-analysis purposes when a single reference table is used for different samples.     

F波、H反射在卒中后肢体痉挛疗效评估中的研究进展

卒中后肢体痉挛是上运动神经元损伤导致高级中枢失去对脊髓牵张反射的抑制,脊髓 反射性增高引起以牵张反射增强为特征的肌肉张力异常。肢体痉挛是卒中后常见并发症之一,严重影 响了卒中患者功能康复。近年来涌现出各类改善卒中后肢体痉挛的治疗方法,但其疗效评价标准不 一,其中以主观性量表评价为主。笔者搜集了近些年国内外卒中后肢体痉挛治疗的临床研究文献,发 现F波、H反射相关参数等客观评价指标被越来越多地与主观评价量表相结合,运用到各类临床研 究的疗效评价中。相对于H反射,F波具有更加灵敏的特点,能更好反映肢体肌张力的变化,常与改良 Ashworth痉挛量表一起作为缺血性卒中后肢体痉挛疗效的评价指标。     

Recruitment curve of the soleus H reflex in patients with neurogenic claudication

The diagnosis of neurogenic claudication (NC) remains uncertain when no definite signs of radicular lesions are found in electrophysiological testing. However, the functional deficit could be demonstrated during the brief time in which the patients complain of pain and weakness in the muscles of the lower limbs after walking. We have used electrophysiological testing of the H reflex and the F wave to document the transient functional derangement expected to occur at the radicular level in patients with NC after walking. We examined the recruitment curve of the soleus H reflex, and the chronodispersion of the posterior tibial nerve F wave, at rest and after a walking exercise that triggered their symptoms in 10 patients with NC, with no positive electrophysiological findings of radicular lesion. The same studies were performed in 5 age-matched healthy volunteers, used as control subjects, who were asked to walk for 30 min. At rest before walking, no abnormalities were found in any of the patients. After walking, the H wave showed a transient increase in its threshold with respect to that of the M wave in 7 patients (70%). Such abnormality lasted for a mean period of 7 min. In 2 of these patients there was also an increase in the F-wave chronodispersion. Our data suggest that nerve conduction is transiently blocked in large myelinated fibers at a radicular level in patients with NC after walking. Partial interruption of the H-reflex circuit could be one of the pathophysiological mechanisms underlying NC. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:985–990, 1998.     

Presence of repeater F-waves in the early stage of Guillain-Barré syndrome

The absence or a prolonged latency of late responses, like F-waves, is a common neurophysiological finding with diagnostic utility in the early Guillain-Barré syndrome. However, the presence and the number of repeater F-waves have not been studied in this disease. In four patients, we report the transient presence of repeater F-waves in nerves of the lower limbs shortly after the onset of the disease. In each patient, the initial (diagnostic) nerve conduction study showed a high incidence of repeater F-waves in the tibial or in the peroneal nerves of one side, with normal distal motor latencies; in the other nerves explored the F-waves were fully abolished and the motor potentials were abnormal. In a second study, done 2-6 weeks later, we observed the abolition of the F-waves or a significant increase of its minimal latency in those nerves in which we had detected the repeaters. The presence of a high number of repeater F-waves with normal latencies in some nerves may be a transient and initial electrophysiological sign useful in the early diagnosis of this disease.     

Usefulness of assessing repeater F-waves in routine studies

Introduction: Repeater F‐waves are sometimes seen in routine studies. Methods: We retrospectively reviewed the clinical significance of repeater F‐waves in median, ulnar, and fibular nerve recordings in 50 healthy subjects and groups of 50 patients each with diabetic polyneuropathy, amyotrophic lateral sclerosis, carpal tunnel syndrome, ulnar mononeuropathy, and L5 root lesion. The number of identical F‐waves and their repetitions in samples of 20 stimuli were estimated. Results: Repeater F‐waves occurred significantly more frequently in all nerves and patient groups than in healthy individuals. Their persistence was negatively correlated with that of non‐repeater F‐waves. Conclusions: Based on the presented material and recording condition it appears that repeater F‐waves differentiate between health and disease but not between different types of pathology of motor neurons or their axons. Even in routinely recorded samples of 20 traces, the index of repeater all F‐waves could be used as a sign of nerve pathology. Muscle Nerve, 2012     

Nerve conduction velocities of single thenar motor axons based on the automated analysis of F waves in amyotrophic lateral sclerosis

The motor unit number estimate (MUNE), motor unit size, and conduction velocity (CV) of thenar surface-recorded motor unit action potentials (S-MUAPs) as collected by the automated F-wave technique were analyzed in 13 patients with amyotrophic lateral sclerosis (ALS) (aged 29–78 years, mean: 61) and 10 age-matched normal subjects (aged 49–81 years, mean: 64). Totals of 96 and 100 thenar S-MUAPs were collected from ALS patients and normal subjects, respectively. There were significant differences (P < 0.001) in the mean estimated numbers and sizes of motor units between the ALS patients (MUNE: 41.9, S-MUAP size: 699.6 μV/ms) and normal subjects (MUNE: 151.2, S-MUAP size: 244.1 μV/ms). The mean S-MUAP CV was 46.3 m/s (range: 32–59) for ALS patients and 56.5 m/s (range: 43–69) for normal subjects (P < 0.001). Mean median motor nerve CVs, measured in the forearm segment, were not significantly different (P = 0.79) between ALS patients (53.4 m/s) and normal subjects (52.9 m/s), however. Thenar motor unit CVs are significantly reduced in ALS patients as compared to normal controls, and this may be due to proximal motor nerve slowing. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:756–761, 1998.     

脊髓型颈椎病病人经颅磁电刺激运动诱发电位的对比研究

目的探讨磁电刺激运动诱发电位（ＭＥＰ）在脊髓型颈椎病（ＣＳＭ）的应用价值，并对其临床相关性进行分析。方法采用经颅磁、电刺激对３０例脊髓型颈椎病病人以及年龄性别等相配匹的３０名健康成人分别于外展小指肌、肱二头肌及下肢展短肌表面进行ＭＥＰ的检测。结果全部病人的ＭＥＰ都出现异常，表现为潜伏期、中枢传导时间（ＣＭＣＴ）延长，时限增宽，波辐降低或不能引出。磁刺激ＭＥＰ的ＣＭＣＴ和皮层刺激潜伏期与脊髓型颈椎病临床日本整形外科协会（ＪＯＡ）评分间有密切相关性，能较好地反映ＣＳＭ病人的病情。结论ＭＥＰ在检测ＣＳＭ病人运动功能方面具有定量评价作用。与电刺激相比，磁刺激ＭＥＰ能更好地反映ＣＳＭ病人的病情。     

Motoneuron excitability and the F wave

For three motoneuron pools that differ in excitability to Ia inputs [tibialis anterior (TA), abductor pollicis brevis (APB), and soleus], F-wave parameters were measured at rest, during voluntary contraction, and following prolonged vibration. There was an inverse relationship between F-wave chronodispersion and F-wave persistence at rest, and this appeared to be related to the ease of recording the H reflex for the motoneuron pool. During a steady voluntary contraction, overall F-wave activity increased in amplitude but decreased in duration for TA and APB. Following vibration of the test muscle at 50 HZ for 10 min there was a long-lasting depression of the H reflexes of TA and APB, but no significant change in F-wave measurements. These findings are consistent with the view that reflex discharges can prevent F waves in low-threshold motor units, and that chronodispersion is affected by the extent of reflex activity; that is, chronodispersion and related F-wave measurements do not measure motor properties exclusively. The findings also suggest that F waves provide a flawed measure of the excitability of the motoneuron pool.     

F波监测面神经功能评估价值实验研究

目的 探讨F波监测对听神经瘤压力模型大鼠面神经功能评估的价值.方法 对58例模型及对照组SD大鼠行面神经F波监测,记录其潜伏期、波幅及与M波比值(F/M);继而行生物素化葡聚糖胺(BDA)面神经逆行示踪,计数面神经核BDA阳性神经元标记率(BDA+-N%);光、电镜检查小脑脑桥角池段面神经;统计分析F/M与BDA+-N%的相关性,并探讨与面神经病理改变的关系.结果 与两对照组比较,小-大各肿瘤组F波潜伏期延长或部分丢失,F/M依次为77.13%,48.91%和11.54%(P<0.001);BDA+-N%依次为77.28%,48.28%和11.55%(P<0.001).各组F/M与BDA+-N%呈线性正相关(r=0.996,P<0.001).面神经光、电镜观察显示病损随球囊体积增大逐渐加重.结论 面神经F波改变可以用于评估面神经功能完整性,反映其病损程度,应有助于术中面神经监测和术后功能预测.     

F waves and motor unit size.

M responses and twitch contractions were evoked in single motor units (MUs) of the first dorsal interosseus muscle by intramuscular microstimulation of motor axons. Two-hundred nine MUs were studied in 21 subjects. Thirty-five MUs (17%) showed F waves in addition to M responses. Twitch force was used to provide an indirect measure of MU size; additionally, twitch contraction time was measured. There was no select group of MUs generating F waves with regard to the above contraction parameters. However, four of five MUs with very high twitch forces, above 70 mN, generated F waves. We conclude that MUs of all sizes produce F waves with similar probability. Only few MUs with very strong twitch forces, i.e., very large MUs, may be more subject to F-wave production and may be involved in the generation of the so-called repeater F waves.