多点刺激法进行运动单位数目估计及其正常值探讨

目的 采用多点刺激法进行运动单位数目估计(MUNE)检测,并探寻其国人正常值.方法 对知情同意的80名健康志愿者进行多点刺激法MUNE:刺激电极分别于腕、腕上6 cm、肘、肘上6 cm共4点刺激正中神经或尺神经,以超强刺激诱发最大波幅M波,然后从0 mA认刺激开始逐渐增加刺激强度,直到出现可辨认的低波幅的单个运动单位电位,稳定后保存,每次记录3个递增的M波,再逐渐增大刺激强度,共获取12个递增的M波.重复做2次.结果 健康志愿者拇短展肌MUNE结果为230.0±35.7,小指展肌242.5±30.2.多点刺激法2次测验所得的MUNE的相关系数为0.88～0.91,变异系数13.20%～15.24%,差异无统计学意义.结论 多点刺激法能测定运动单位数目,可重复性良好.     

自动递增刺激法运动单位估数及其对肌萎缩侧索硬化的临床意义

目的　探索使用自动递增刺激法记录运动单位估数 (MUNE)对肌萎缩侧索硬化 (ALS)的临床诊断及病情判定意义。方法　使用自动递增刺激法记录 31名无神经肌肉疾病的健康人 [年龄35～ 5 8岁 ,平均 (43 7± 6 1)岁 ]的 5 1条大鱼际肌和 5 2条小鱼际肌MUNE数值 ;同时记录并比较 2 0例临床确诊的散发性ALS患者 [年龄 35～ 6 3岁 ,平均 (47 1± 6 3)岁 ]的 36条大鱼际肌和 38条小鱼际肌的MUNE。结果　健康对照组 5 1条大鱼际肌MUNE为 2 5 2 7± 79 4 ,5 2条小鱼际肌MUNE为2 4 1 6± 70 5 ,然而 ,2 0例ALS患者的 36条大鱼际肌及 38条小鱼际肌MUNE分别仅为 5 8 6± 70 9和 6 9 4± 70 5。健康对照者与ALS患者两组之间的大、小鱼际肌MUNE差异有显著意义 (P <0 0 0 1)。结论　使用自动递增刺激法记录的正常人大、小鱼际肌MUNE与ALS患者的MUNE相比具有显著统计学差异 ,这种差异对于ALS的临床诊断和病情判定有重要帮助。     

体感诱发电位在重度腕管综合征诊断中的应用

目的探讨临床通过检测正中神经体感诱发电位(SEP)中潜伏期波N60计算重度腕管综合征(CTS)感觉神经传导速度(SNCV)的方法。方法检测对象为15例17腕复合肌肉动作电位(CMAP)未能引出的重度CTS患者和6名健康对照者(作者医院健康查体者),检测点为掌远侧横纹(0点)近端2cm( 2点)及远端2cm(-2点)和4cm(-4点)处3点及中指1点共4点,以患者所能感知最低刺激的3～4倍强度的1.1Hz0.2ms方波分别刺激腕关节和中指所获的SEP峰间差计算SNCV。结果通过N60波峰间差计算所得自掌远侧横纹到中指间的SNCV范围正常对照组为45.1～89.2m/s,平均(67.4±13.0)m/s;在进行中指刺激检测N60波的12腕中,8腕N60波明显延长,SNCV为9.3～21.2m/s,平均(15.6±4.2)m/s(P<0.01),另4腕完全未测出。结论正中神经SEP的N60波可作为对运动和感觉电位均未测出的重度CTS患者进行诊断时判断传导异常的客观指标之一,通过这一方法测得的神经传导速度可供临床参考。     

统计法运动单位数目估计技术的临床应用研究

目的研究统计法运动单位数目估计(MUNE)技术在下运动神经元轴索变性和脱髓鞘疾病诊断中的价值。方法共收集41例肌萎缩侧索硬化(ALS)、25例获得性脱髓鞘疾病和48名健康对照,对正中神经/拇短展肌采用统计法MUNE技术进行测定,分析比较运动单位数目、表面记录的运动单位电位(SMUP)平均波幅、最大SMUP波幅以及刺激反应功能曲线在3组研究对象之间的特点。结果在ALS、脱髓鞘疾病和健康对照组,数目加权的运动单位数目分别为49±20、109±38、118±12,平均SMUP波幅分别为(121±51)、(58±33)、(110±25)μV,最大SMUP波幅分别为(263±150)、(107±74)、(139±36)μV,复合肌肉动作电位分别为(5.8±2.8)、(6.5±4.6)、(13.1±2.8)mV。与健康对照组比较,ALS组运动单位数目明显下降(P<0.01)、最大SMUP波幅明显增高(P<0.01);与健康对照组和ALS组比较,脱髓鞘组平均SMUP波幅明显下降(P<0.01),而运动单位数目、最大SMUP波幅与健康对照组差异无统计学意义。ALS组刺激反应功能曲线明显不规则,最大采样区间明显增大。结论ALS患者运动单位数目降低,最大SMUP波幅增高,刺激反应功能曲线上的最大采样区间增大;脱髓鞘患者平均SMUP波幅明显下降。在某些情况下,根据上述特点,可以将统计法MUNE技术作为一种无创的方法,来协助鉴别周围神经脱髓鞘和轴索损害。     

帕金森病患者的运动单位数目评价

目的对帕金森病患者的运动单位数目进行检测,观察有无运动单位数目的下降。方法采用半自动递增刺激法对20例帕金森病患者的大鱼际肌（Thenar）和趾短伸肌（EDB）进行运动单位数目估计（MUNE）,并与对照组12名健康受试进行比较。结果帕金森病患者的大鱼际肌运动单位数目与对照组比较无差异,趾短伸肌的运动单位数目与对照组相比虽有降低趋势,但差异无统计学意义（P〉0．05）。帕金森病患者的全部运动单位面积及单个运动单位面积与正常对照比较差异无统计学意义（P〉0．05）。结论帕金森病患者运动单位数目与正常对照相比差异无统计学意义,提示锥体外系病变对运动神经元数目影响可能并不显著。     

慢性炎症性脱髓鞘性多发性神经病多节段神经电生理研究

目的分析慢性炎症性脱髓鞘性多发性神经病(CIDP)节段性神经电生理表现。方法收集2013年1月~2014年8月于吉林大学第一医院神经内科就诊的22例CIDP患者,行正中神经及尺神经多节段神经电生理检测,正中神经刺激点包括:腕、肘、腋、Erb’s点;尺神经刺激点包括:腕、肘下、肘上、腋、Erb’s点。分析各节段神经电生理改变。结果 22例患者电生理各节段均出现明显的脱髓鞘改变,正中神经各节段(腕以下、腕-肘、肘-腋、腋-Erb’s点)运动传导时间较正常值延长分别为:125%、70%、122%、134%;尺神经各节段(腕以下、腕-肘下、肘下-肘上、肘上-腋、腋-Erb’s点)运动传导时间较正常值延长分别为84%、97%、140%、146%、149%。正中神经各刺激点(肘、腋、Erb’s点)传导阻滞(CB)例数分别为:2、6、14;尺神经各刺激点(肘下、肘上、腋、Erb’s点)CB例数分别为:5、4、10、16。结论 CIDP存在明显脱髓鞘的电生理改变,但在周围神经近端各节段脱髓鞘程度较远端重,CB以近端腋点、Erb’s点明显,多节段神经电生理检测更有利于协助CIDP的诊断并判断神经损害的严重程度。     

统计法运动单位数目估计技术的可重复性研究

目的 对统计法运动单位数目估计技术的可重复性进行分析,为临床应用提供依据.方法 收集19例肌萎缩侧索硬化患者和27例正常对照者的临床资料,于同期对同一侧正中神经/拇短展肌进行两次统计法运动单位数目估计检测,计算其变化率,根据不同分析方法判断统计法运动单位数目估计技术的可重复性.结果 肌萎缩侧索硬化组受试者前后两次运动单位数目估计测值分别为(47.21±23.50)和(44.84±23.01),正常对照组受试者分别为(119.51±9.84)和(120.56±10.60),差异均无统计学意义(P＞0.05);两次测值之间均存在明显正相关关系(P＜0.05).肌萎缩侧索硬化组受试者运动单位数目估计测值的变化率P50(P25,P75)为9.52%(5.63%,25.00%),正常对照组受试者为5.00%(2.34%,9.40%),差异有统计学意义(Z=2.387,P=0.017),提示肌萎缩侧索硬化组受试者的可重复性低于正常对照组.肌萎缩侧索硬化组5例(5/19)患者运动单位数目估计测值的变化率＞25.00%,其正中神经远端复合肌肉动作电位波幅为1.90～3.20mV;14例(14/19)变化率≤25.00%,其正中神经远端复合肌肉动作电位波幅为3.80～12.40mV.结论 肌萎缩侧索硬化患者和正常对照者统计法运动单位数目估计检测均具有较好的可重复性,但是肌萎缩侧索硬化患者的可重复性低于正常对照者.建议在应用统计法运动单位数目估计,技术进行随访观察时,尽量选择复合肌肉动作电位波幅较高者进行检测.     

神经传导速度在肌萎缩侧索硬化中的诊断价值

目的　研究肌萎缩侧索硬化 (ALS)患者中神经传导速度的改变 ,建立量化评定肌萎缩侧索硬化病情轻重的神经生理指数。方法　对 2 1名ALS患者的 3 0条尺神经、3 2条正中神经及 2 4名健康对照组的 3 8条尺神经、40条正中神经进行神经运动传导速度 (MCV)及感觉传导速度 (SCV)和F波的检测。两组间数据进行统计学分析。结果　ALS组正中神经、尺神经运动传导速度的远端潜伏期 (DML)、肌肉动作电位 (CAMP波幅及面积、F波的出现率 )较对照组有显著性差异。而两组MCV、SCV、F波的潜伏期差异无显著性。ALS组中 1 0名小指展肌的肌力与 (CAMP波幅 /DML×F出现率 )的数值有显著的相关性 (r=0 89,P <0 0 1 )。结论　 (CMAP波幅 /DML×F波的出现率 )是一种有效的客观的电生理指数 ,可对ALS病情进行量化评估     

不同阶段肌萎缩侧索硬化患者肌电图的研究

目的研究不同阶段肌萎缩侧索硬化(ALS)患者的定量肌电图(EMG)表现,寻找早期诊断ALS的敏感电生理指标。方法对60例ALS患者进行定量EMG检查,分析不同阶段运动单位动作电位(MUPs)多相参数、自发电位和大力收缩募集相变化,并与健康对照组进行比较。结果不同阶段ALS EMG表现不同,从最早期阶段到最后阶段可分为N0~N56个连续的电生理阶段。N2期MUPs的时限、波幅、面积、运动单位指数(SI)、多相波数值均较健康对照组显著升高(均P<0·001),N0、N4期MUPs部分多相参数数值明显升高(P<0·05);自发电位在病变的各个阶段均可见到,以N2~N5多见,分别为63·6%、83·0%、91·2%、100%。结论ALS患者早期阶段如出现自发电位,即为下运动神经元受累的特征表现;定量EMG检查中运动单位面积和波幅增大是其显著特点。     

正中神经和尺神经分段刺激在慢性炎性脱髓鞘性多发性神经病中的电生理研究

目的 探讨运动神经传导速度(MCV)、复合肌肉动作电位(CMAP)与肌力减退的关系和传导阻滞(CB)在慢性炎性脱髓鞘性多发性神经病(chronic inflammatory demyelinating polyradiculoneuritis,CIDP)中的表现特点.方法 30例CIDP患者在进行常规MCV、远端潜伏期(DML)、F波、感觉神经传导速度(SCV)、肌电图(EMG)测定的基础上,在正中神经采用由远到近的“腕-肘-腋-Erb's点”4点3段刺激,尺神经采用由远到近的“腕-肘下-肘上-腋-Erb's点”5点4段刺激,记录各段刺激后CMAP各参数及MCV的变化.结果 CMAP波幅衰减、面积衰减、时程增加以及MCV减慢与临床肌力减退无相关性,dCMAP波幅与上肢远端肌力呈正相关;患者中80.00％在正中神经、73.33％在尺神经发现了1个或多个节段的CB,且出现节段无明显选择性.结论 dCMAP波幅降低与CIDP患者肌力减退有相关性.在CIDP中CB出现率高,且较为弥散地在各节段中出现.     

Stratifying disease stages with different progression rates determined by electrophysiological tests in patients with amyotrophic lateral sclerosis

By determining the usefulness of motor unit number estimate (MUNE) and compound muscle action potential (CMAP) amplitude in patients with amyotrophic lateral sclerosis (ALS), we tried to find an effective way to stratify the disease stages. In all, 112 consecutive ALS patients were enrolled, among whom 73 were elicited in a longitudinal study. MUNE by the standard incremental technique, the average CMAP amplitude, total Medical Research Council (MRC) score, ALS‐functional rating score (ALS‐FRS), Appel ALS rating scale (AARS), and forced vital capacity (FVC) were performed at baseline and months 3, 6, and 12 after study entry. We found MUNE correlated with CMAP amplitude (P < 0.01) as well as MRC score (P < 0.01) in regionally concordant distal muscles. Both MUNE and CMAP amplitude correlated significantly with ALS‐FRS (P < 0.05) and AARS (P < 0.01). A MUNE decrease was observed at months 3, 6, and 12 compared with baseline, and the rate of change at month 3 was 50.47%. The decrease in MUNE over the first 3 months was significantly greater than other measurements. We arbitrarily divided the patients into three stages: (1) rapid progression: the rate of change of MUNE and CMAP amplitude during the first 3 months exceeded 50%; (2) moderate progression: the rate of change of MUNE was greater than 50% but CMAP amplitude was less than 50%; (3) slow progression: the rate of change of both MUNE and CMAP amplitude were less than 50%. Comparing the rate of ALS‐FRS descent per year using one‐way ANOVA showed a significant difference among the three groups (P < 0.01). Muscle Nerve 39: 304–309, 2009     

Thenar motor unit number estimates using the multiple point stimulation technique: Reproducibility studies in als patients and normal subjects

Thenar motor unit number estimate (MUNE) reproducibility was assessed in 20 patients with amyotrophic lateral sclerosis (ALS) and 16 normal subjects using the multiple point stimulation (MPS) technique. The MUNE was calculated by dividing the thenar compound muscle action potential negative-peak (n-p) area by the mean n-p area of 10 lowest threshold, all-or-nothing, surface-recorded motor unit action potentials. Two trials (test–retest) were performed by the same examiner either on separate days or on the same day with new electrode placements. The mean test MUNE was 43.4 (SD: 35.9, range: 6–145) for ALS patients and 219.4 (SD: 80.8, range: 122–368) for normal subjects. Test–retest MUNE differences were not significant for ALS patients or normal subjects. The test–retest correlation coefficient (r) was 0.99 for ALS patients and 0.85 for normal subjects. The mean difference between test–retest values was 10% for ALS patients and 17% for normal subjects. Test–retest reproducibility of the thenar MUNE using the MPS technique is high in both ALS patients and normal subjects. The reliability of the MPS technique in estimating motor unit numbers may make it a useful outcome measure in following the course of patients with progressive lower motor neuron disease, especially those enrolled in experimental drug trials.© 1995 John Wiley &Sons, Inc.     

Multipoint incremental motor unit number estimation versus amyotrophic lateral sclerosis functional rating scale and the medical research council sum score as an outcome measure in amyotrophic lateral sclerosis

Introduction:

Monitoring the disease progression in amyotrophic lateral sclerosis (ALS) is a challenge due to different rates of progression between patients. Besides clinical methods to monitor disease progression, such as the ALS functional rating scale (ALSFRS) and the medical research council (MRC) sum score, quantitative methods like motor unit number estimation (MUNE) are of interest.

Objective:

The objective of the present study is to evaluate the rate of progression in ALS using multipoint incremental MUNE and to compare MUNE, ALSFRS and MRC sum score at baseline and at 6 months for progression of the disease.

Materials and Methods:

Multipoint incremental MUNE using median nerve, ALS-FRS and MRC sum score was carried out in 29 ALS patients at baseline and then at 6 months.

Results:

Of the 29 ALS patients studied, the mean MUNE at baseline was 21.80 (standard deviation [SD]: 19.46, range 4-73), 15.9 in the spinal onset group (SD: 14.60) and 30.16 (SD: 22.89) in the bulbar onset group. Spinal onset patients had 74.02% of baseline MUNE value while bulbar onset patients had only 24.74% baseline value MUNE at 6 months follow-up (Unpaired t-test, P = 0.001). ALSFRS and MRC sum score showed statistically significant decline (P < 0.001) at 6 months follow-up. MUNE had the highest sensitivity for progression of the disease when compared to the ALS FRS and MRC sum score.

Conclusion:

Multipoint incremental MUNE is a valuable tool for outcome measure in ALS and other diseases characterized by motor unit loss. The rate of decline of multipoint incremental MUNE is more sensitive than that of MRC sum score and ALSFRS-R, when expressed as the percentage change from baseline.     

Reproducibility of statistical motor unit number estimates in amyotrophic lateral sclerosis: comparisons between size- and number-weighted modifications

Motor unit number estimations (MUNEs) can directly assess motor unit populations in muscle and quantify the degree of physiological or pathological motor unit degeneration. A high degree of reproducibility and reliability is required of any effective quantitative tool. MUNE is being increasingly applied clinically, and statistical MUNE has several advantages over alternative techniques. Nevertheless, the optimal method of applying statistical MUNE with respect to its reproducibility has not been established. We performed statistical MUNE by selecting the most compensated compound muscle action potential (CMAP) area as a test area and modified the results obtained by using the weighted mean surface-recorded motor unit potential (SMUP). MUNE measurements made in patients with amyotrophic lateral sclerosis (ALS) showed better reproducibility after incorporating the size-weighted modification. Therefore, we suggest that the size-weighted MUNE in combination with the selection of testing "neurogenically compensated" CMAP areas is a more reliable method of statistical MUNE analysis in ALS patients.     

Monitoring disease progression using high‐density motor unit number estimation in amyotrophic lateral sclerosis

In amyotrophic lateral sclerosis (ALS), progressive motor neuron loss causes severe weakness. Functional measurements tend to underestimate the underlying pathology because of collateral reinnervation. A more direct marker of lower motor neuron loss is of significant importance. We evaluated high‐density motor unit number estimation (MUNE), as compared with the ALS Functional Rating Scale (ALSFRS) and maximal compound muscle action potential (CMAP) amplitude, for monitoring and classifying disease progression. MUNE showed good reproducibility (intraclass correlation coefficient = 0.86). MUNE showed a significantly greater decrease than the ALSFRS, the Medical Research Council (MRC) scale, and CMAP amplitude. Patients could be stratified into groups with rapidly or slowly progressive disease based on a decrement in MUNE at 4 months from baseline; ALSFRS score at 8 months was significantly lower in the rapidly progressive group. MUNE was sensitive to motor neuron loss early in the disease course when compared to other clinical measures. Stratification of patients based on a decrease in MUNE seems feasible. Muscle Nerve, 2010     

Motor unit number estimation,isometric strength,and electromyographic measures in amyotrophic lateral sclerosis

Pathologic progression in amyotrophic lateral sclerosis (ALS) results from motor neuron death, while the clinical expression also reflects the compensatory effects of collateral reinnervation consequent to lower motor neuron loss. In a cross-sectional study of ALS subjects, we made comparisons between motor unit number estimation (MUNE) values and several measures reflecting collateral reinnervation, including isometric strength, compound muscle action potential (CMAP) amplitude, surface motor unit action potential (S-MUAP) amplitude, fiber density (FD), macro-EMG potential amplitude, turns-to-amplitude (T/A) ratio, and amplitude and recruitment pattern of low threshold voluntary motor units in elbow flexor muscles. Before comparisons were made, testretest reproducibility of these measures was assessed in ALS subjects, and is highest for isometric strength, and lower but similar for EMG measures. When the effects of multiple comparisons are considered, borderline significant correlations are found between MUNE values and isometric strength. Neither MUNE values nor isometric strength are significantly correlated with macro-EMG amplitude, FD, T/A ratio, or amplitude and recruitment rate of low threshold voluntary motor units. There are significant correlations of CMAP and S-MUAP with MUNE values, but these are statistical artifacts with no independent interpretation. We conclude that collateral reinnervation prevents isometric strength and EMG measures from accurately reflecting lower motor neuron death in ALS. MUNE measurements are better suited to provide insight into the true natural history of the disease process and may be clinically useful to follow progression and response in drug trials. © 1993 John Wiley & Sons, Inc.     

Transcutaneous cervical root stimulation in the diagnosis of multifocal motor neuropathy with conduction block

OBJECTIVES: To determine if transcutaneous electrical stimulation of the cervical roots can be used to diagnose proximal conduction block (CB) in multifocal motor neuropathy (MMN) and whether it can reliably distinguish MMN from amyotrophic lateral sclerosis (ALS). METHODS: Compound muscle action potentials (CMAPs) over the abductor digiti minimi (ADM) were evoked by supramaximal stimulation of the ulnar nerve at the wrist, below elbow, above elbow, axilla, Erb's point, and C8/T1 cervical roots in three groups of patients: 31 patients with ALS, nine patients with MMN, and 31 controls. Supramaximal stimulation at Erb's point and the C8/T1 roots was carried out using a transcutaneous high voltage electrical stimulator. The negative peak amplitude, area, and duration of the CMAP were measured and normalised to that from the wrist. The percentage change in each segment in these parameters was calculated and compared between the different groups. RESULTS: At stimulation sites proximal to the elbow, there were no significant differences in relative CMAP amplitude, area, or duration between controls, ALS patients, and MMN patients with clinically unaffected ulnar nerves. Similarly, the percentage segmental change between adjacent stimulation sites showed no significant differences. In six studies of MMN patients with weakness in ulnar hand muscles, the decrease in CMAP amplitude between the C8/T1 roots and Erb's point exceeded the mean + 2 SD of the control data. CONCLUSION: Cervical root stimulation can quantify CB in the most proximal segment of the ulnar nerve, a fall in CMAP amplitude if greater than 25%, indicating block, and should be used routinely in the evaluation of patients suspected of having MMN, especially when distal stimulation has proved unhelpful.     

Motor unit number index and compound muscle action potential amplitude

ObjectivesMUNIX (motor unit number index), derived from the compound muscle action potential (CMAP) and surface EMG interference pattern (SIP) has become popular as a substitute for motor unit number estimation (MUNE). This study was undertaken to determine why, in recent recordings from amyotrophic lateral sclerosis (ALS) patients and healthy controls, we found that MUNIX values resembled CMAP amplitudes more closely than MUNE values.MethodsThe relationship between MUNIX and CMAP and SIP amplitudes was investigated by a theoretical analysis and by reanalysing the data from the previous study.ResultsTheory indicates that when motor unit potentials overlap extensively, information about motor unit size and number is lost, and MUNIX depends only on CMAP area and power. Accordingly, MUNIX values were found to be sensitive to changes in CMAP amplitude but insensitive to changes in SIP amplitude. The reproducibility of MUNIX measurements in healthy controls was found to depend almost entirely on correlation with CMAP properties.ConclusionsMUNIX gives misleading information about motor unit numbers in healthy controls, and provides little information about loss of motor units in ALS patients beyond that given by simple CMAP amplitude measurements.SignificanceMUNIX should not be interpreted as a MUNE method.     

A longitudinal study comparing thenar motor unit number estimates to other quantitative tests in patients with amyotrophic lateral sclerosis

The following data were obtained on 21 amyotrophic lateral sclerosis (ALS) patients, aged 36–76 years (mean: 58 years), at baseline and months 4, 8, and 12: thenar motor unit number estimate (MUNE) using multiple point stimulation, mean thenar surface-recorded motor unit action potential negative-peak area, thenar compound muscle action potential amplitude, isometric hand grip strength, total Medical Research Council (MRC) manual muscle testing score, Appel ALS rating scale, and forced vital capacity (FVC). The absolute mean rate of change per month was significantly greater (P < 0.01) for MUNE values than for MRC and FVC values in the 21 ALS patients. In a subset of patients (n = 6) with slowly progressive disease, the absolute mean rate of change per month was significantly greater (P < 0.01) for MUNE values than for all other test values. In addition, MUNE values were the most sensitive index for documenting changes in disease progression over time. © 1997 John Wiley & Sons, Inc. Muscle Nerve, 20, 179–185, 1997.