肌电图肌源性损害合并神经源性损害71例临床分析

目的分析和探讨肌电图(EMG)肌源性损害合并神经源性损害的临床和电生理特点。方法检索作者医院EMG数据库,收集EMG表现为肌源性损害合并神经源性损害患者共71例,对其临床和电生理特点进行回顾性分析。结果在此组患者中,最常见的是结缔组织病,共63例(占88.7%)。其余依次为:肿瘤、进行性肌营养不良、AIDS、甲状腺功能亢进(甲亢)。在全部患者中,临床表现为近端无力者55例(占77.5%),有感觉症状体征者27例(占38.0%),肌肉萎缩者12例(占16.9%)。患者的三角肌52例(占73.2%)、股四头肌49例(占69.0%)EMG表现为肌源性损害,其中上下肢同时为肌源性损害者32例(占45.1%)。所合并存在的神经源性损害主要表现为多发性周围神经病(39例)、单神经病(27例)、颈或腰骶神经根病(5例)。结论EMG检查有助于检出临床下神经肌肉病变,电生理检查发现肌源性合并神经源性损害的同时分析肌病所合并周围神经病变类型将有助于揭示病变性质。     

伴神经源性损害的非炎性肌病临床与电生理特点

目的探究伴神经源性损害的非炎性肌病患者临床及电生理特点。方法回顾性收集自2015至2017年我院明确诊断为肌肉疾病且在我院肌电图室完成常规肌电图检查的所有患者,分析伴神经源性损害且诊断为非炎性肌病患者的临床及电生理特点。结果共收集经基因检测或肌肉活检明确诊断为肌肉疾病患者110例,肌电图出现神经源性损害者为10例,其中出现神经源性损害且为非炎性肌病者4例。上述4例患者分别为1例脂质沉积性肌病、1例中央轴空病、1例包涵体肌病及1例Welander型远端型肌病;肌电图均合并神经源性损害,同时伴或不伴周围神经损害。结论少数非炎性肌病患者肌电图可出现神经源性损害,肌电图不能作为诊断肌肉疾病的单独标准。     

98例神经肌肉病的临床、肌电图与病理研究

目的 探讨肌电图（EMG），肌活检对神经肌肉病的诊断价值。比较EMG，肌活检及初始临床诊断3者之间的关系。方法 将98例神经肌肉病分成肌病。重症肌无力和运动神经元病3组进行研究。结果 肌病组（80例），68.8%(55/80)肌活检，75%（60/80）EMG呈肌源性损害；重症肌无力组（10例）；针极EMG（不包括重视频率电刺激）及肌活检均未显示特异性改变；运动神经元病组（8例），75?/8）肌活检，100%（8/8）EMG呈神经源性损害。结论 肌活检对肌病明确诊断可提供直接信息。对运动神经元病只能做出神经源性损害结果。缺乏特异性。EMG对神经肌肉病只能做出分类诊断；单纯凭借初始临床资料易导致该类疾病误诊。     

肌管聚集性神经肌肉病二例报告

目的 报道２例类似重同无力的肌管聚集性神经肌肉病的神经肌肉接头形态改变。方法 对２例病人进行临床、电生理和肌肉病理检查。结果 例１为５３岁男性，主要表现为进行性肌无力和肌疲劳现象。血清抗乙酰胆碱受体抗体阴性，重复神经刺激出现肌电图波幅低频递减，远端肌电图显示神经源性损害。例２为２０岁男性病人，表现为肌无力和肌疲劳现象，肌电图重频刺激出现明显递减现象。２例病人的肌肉病理检查均发现，在Ⅱ型肌纤维内出现     

成人型近端脊髓性肌萎缩症的临床和肌肉病理学研究

目的 总结成人型近端脊髓性肌萎缩症(ASMA)临床和肌肉病理学特征，以提高对ASMA的认识。方法 对27例完成肌肉活检的ASMA患者进行临床及肌肉病理学分析。结果 该病多于45岁左右发病，起病及进展均缓慢，主要表现为近端肌肉无力、肌肉萎缩、肌束震颤，锥体束和周围神经一般不受累。4例患者肌酶增高。所有患者肌电图检查示神经源性损害，其中2例伴肌源性改变。肌肉活检光镜下见神经源性肌萎缩，其中3例伴肌源性损害。电镜下见肌原纤维数量减少、排列紊乱、部分断裂，Z线变粗或呈波浪样以及肌核聚集。结论 结合临床表现进行肌肉活检对ASMA诊断及鉴别诊断具有重要价值。     

脂质沉积性肌病合并周围神经病的临床和神经电生理研究

目的研究脂质沉积性肌病合并周围神经损害和不伴周围神经损害的临床及神经电生理特点。方法对19例病理证实的脂质沉积性肌病中7例合并周围神经损害（第一组）和12例不伴周围神经损害的患者（第二组）进行了常规肌电图、正中神经和胜后神经感觉传导速度及运动末端潜伏期测定。结果发现临床上两组不同卢、是前者病程较后者长（P＜0．01）；肌电图提示运动单位动作电位（MUAPS）时限第一组较第二组宽，去除多相波后更明显（P＜0．01），部分合并神经源性损害；神经传导速度测定结果提示，第一组可见感觉和运动神经传导速度减慢及感觉神经动作电位波幅降低。结论对临床上有典型的肌病症状、电生理为肌源性损害合并神经源性损害或单纯神经源性损害应考虑脂质沉积性肌病的可能，肌肉和周围神经活检是非常必要的。     

神经电生理检查判断眼肌型重症肌无力的敏感度分析

目的：分析眼肌型重症肌无力（OMG）患者的神经电生理特点,为临床诊断提供有价值的依据.方法：对42例临床诊断为OMG患者进行单纤维肌电图、重复神经电刺激和肌电图检测.结果：伸指总肌的单纤维肌电图34例异常,重复电刺激异常23例;肌电图示14例肌源性损害.结论：OMG患者单纤维肌电图是一种敏感度较高的检测方法,其次为重复神经电刺激,其肌肉检测阳性率高低依次为眼轮匝肌、肱二头肌及小指展肌.     

神经肌炎--附26例临床及病理改变

目的 通过研究神经肌炎患者的临床及病理特点来探讨神经肌炎能否作为一种独立的疾病实体。方法 分析26例神经肌炎的临床和病理改变。结果 神经肌炎的主要临床表现为肢体无力、疼痛、肌萎缩。15例肌酶正常，11例肌酶增高，以CK增高为主。肌电图可表现为神经源性损害和／或肌源性损害。病理活检可见神经肌肉大量炎性细胞浸润，神经脱髓鞘改变。结论 神经肌炎与多发性肌炎相比有其独特之处，神经肌炎作为一种独立的疾病，诊断主要依靠肌电图和病理。     

多发性肌炎患者神经电生理特点分析

目的增进对多发性肌炎患者肌电图特点的认识,提高其检查的阳性率。方法对91例多发性肌炎患者进行肌电图(EMG)、神经传导速度测定。结果肌电图异常率为87.9%,肌源性损害者占79.1%,神经源性损害者占8.8%。其中插入电位延长、自发电位的阳性率分别为6%和52%,肱二头肌出现率较高,外展拇短肌出现率最低(p<0.05);运动单位电位(MUP)时限缩短的阳性率为71%,胫前肌出现率最高,外展拇短肌最低(p<0.05);MUP波幅降低的阳性率较低,仅为7%;多相波增多的阳性率为29%,胫前肌出现率最高,股四头肌最低(p<0.05);重收缩时波形异常的阳性率为26%,以股四头肌出现率最高;重收缩时峰值电压降低的阳性率为31%,胫前肌出现率最高,外展拇短肌最低(均p<0.05)。5例患者EMG呈神经源性损害,1例感觉神经传导速度减慢,2例运动神经传导速度减慢。肌电图正常组、肌源性损害组及神经源性损害组患者的病程、年龄无明显差异。结论 EMG对多发性肌炎诊断的阳性率为87.9%,其中以MUP时限缩短出现率最高为71%,其次为自发电位为52%。EMG异常最多见于肱二头肌、股四头肌和胫前肌。     

重症肌无力合并肌电图肌源性损害53例临床和电生理特点

目的研究重症肌无力（myasthenia gravis，MG）合并肌电图肌源性损害患者的临床和电生理特点。方法收集1998-2006年中国医学科学院北京协和医院神经科肌电图室收治的MG合并肌源性损害患者共53例，对其临床和电生理特点进行回顾性分析。结果在本组患者中，早发型患者占69．81％（37／53），早发型中女性患者明显多于男性（分别为26例和11例,X^2=5．281，P〈0．05）。延髓部肌肉受累者多见，占50．94％（27／53）。仅1例患者具有肌肉萎缩的临床表现。合并其他免疫相关疾病患者占15．09％（8／53）。2例患者（3．77％）重复频率电刺激正常，但肌电图示肌源性损害。15例患者进行肌酶谱检查，其中1例轻度异常。结论对于MG合并肌源性损害的患者，要结合临床特征、电生理检查等进行综合分析来区别“真性”和“假性”的肌源性损害。行甲状腺功能、自身抗体等检查有助于发现潜在的自身免疫系统疾病。     

Automatic analysis of the electromyographic interference pattern using the turns: amplitude ratio

This study was performed to compare different techniques of analyzing the electromyographic interference pattern (IP). Recordings were made from the biceps muscle with a concentric needle electrode at different sites and at different constant levels of voluntary contraction. The number of turns per second (NT), the mean amplitude change between successive turns (MA) and NT:MA ratio were determined for epochs of 1 sec duration. Normal limits of individual epoch NT:MA ratios and the mean value of NT:MA ratio obtained from all epochs in each muscle were determined. The mean NT:MA ratio was less in normal males than in females. IP recordings were made in the biceps muscle of 69 patients with neuropathy and 54 patients with myopathy, though this muscle was not necessarily affected by the disease in all patients. The IP was abnormal by visual inspection in 82% of patients compared to 61% based on NT:MA ratio and 74% using a technique that automatically quantitates some features of the IP that are assessed subjectively by an electromyographer. All techniques demonstrated IP abnormalities in more than 80% of the muscles that were moderately to severely weak. Though measuring the NT:MA ratio without monitoring the force of contraction is not as sensitive as other IP analysis techniques, it may be useful in quantitating abnormalities when other techniques are not available.     

Evaluation of an automatic method of measuring features of motor unit action potentials

This study was performed to evaluate an automatic method of motor unit action potential (MUAP) analysis developed in our laboratory. MUAPs were recorded from the biceps brachii muscle of 68 normal subjects and 122 patients with nerve or muscle disease. The values of mean MUAP durations from normal subjects obtained by automatic analysis were similar to those reported in the literature. However, the normal range of MUAP amplitude and the incidence of polyphasic MUAPs were much higher. Normal ranges of mean MUAP area, area/amplitude ratio, and the number of turns were also defined. Automatic analysis demonstrated an abnormality of at least one MUAP feature in 70% of patients. There was concordance between automated analysis and visual assessment of MUAPs in 76% of patients with neuropathy but in only 50% of patients with myopathy. The relationships between different MUAP features seen in neuropathy and myopathy are explained in physiologic terms.     

Principal component analysis of the features of concentric needle EMG motor unit action potentials

Motor unit action potentials (MUAPs) were recorded from the biceps muscle of normal subjects and of patients with nerve or muscle diseases. Principal component analysis of the MUAP amplitude, area, area/amplitude ratio, duration, and the number of turns and phases produced three components that among them contained 90% of the variance of the data set. Thus the dimensionality of data was reduced from six to three. The first component reflected changes in the size of the MU, whereas the second reflected variations in the arrival time at the recording electrode of the action potentials of muscle fibers in the motor unit. The third factor reflected local loss of muscle fibers within the MU territory. Patterns of variations in the three components were different in patients with neuropathy and myopathy.     

Turns-amplitude analysis in normal and myopathic facial muscles

The purpose of this study was to assess turns/amplitude analysis (TAA) as an objective alternative to conventional qualitative electromyography (EMG) for detection of myopathy in facial muscles. Normal values of TAA parameters were calculated in the frontalis and mentalis muscles of 26 control subjects. We estimated the slope of the regression line of mean amplitude/turn values (MA) plotted against the number of turns/second (NT) and the resulting clouds. The 95% confidence limits of the cloud data were drawn as an ellipse. The sensitivity of TAA was determined from a group of 35 myopathic patients and specificity from a second group of 25 control subjects. Significant differences for every TAA parameter were found between frontalis and mentalis. Cumulative sensitivity and specificity of TAA for frontalis and mentalis were 74.6%, 56.5%, and 73.3%, 70.8%, respectively. With at least two of the aforementioned criteria abnormal, the sensitivity and specificity for frontalis and mentalis were 61.3%, 82.6%, and 56.7%, 100.0%, respectively.     

Diagnostic yield of analysis of the pattern of electrical activity and of individual motor unit potentials in myopathy.

The analysis of the pattern of electrical activity and of individual motor unit potentials in the same muscle both identified about 90% of 41 patients as having a myopathy. The pattern of electrical activity was analysed during a force which was a fixed fraction of maximum; individual motor unit potentials were analysed during weak effort. The two methods supplement each other as some of the patients were identified only by one or by the other of the two procedures. The parameter of the pattern of electrical activity which was most often abnormal was the ratio: numbers of turns to mean amplitude between turns.     

Electrical muscle activity during a gradual increase in force in patients with neuromuscular diseases

The electrical activity of the brachial biceps muscle from 31 patients with neuromuscular diseases were quantified during a gradual increase in force from zero to maximum within 10 sec. In patients with myopathy the ratio of potential reversals per 100 msec (turns) to mean amplitude was increased more often at 10% and 20% of maximum force than at greater force (i.e., in four-fifths of the patients). Similarly, the mean amplitude as a function of turns was more diagnostic at low than at high force, possibly due to an affection of low threshold motor units. In 14 patients with neurogenic disorders turns was decreased in nearly two-thirds of the patients at a force of 20% and 30% of maximum. In muscles where the force is easily determined it is suggested to quantitate the electrical activity during constant forces of 10% and 30% of maximum. In muscles where the force is difficult to determine the analysis of the ratio of turns to mean amplitude should be performed when motor unit potentials begin to interfere.     

Exercise test in muscle channelopathies and other muscle disorders

We studied the percentage change in compound muscle action potential (CMAP) amplitude and area during and after a 5-min maximal contraction of the muscle. The exercise test (ET) was performed on 64 patients with different muscle disorders and on 46 normal controls. The range of normal ET values was defined as the mean + 2 SD of the control values. The mean sensitivity of the test was 63% in the whole group with ion channel muscle disorders, the highest sensitivity being seen in primary periodic paralysis (81%) and the lowest in chloride channelopathies (17%). In thyrotoxic periodic paralysis, the ET was abnormal in the three of the four patients studied. In patients with myotonic dystrophy, a smaller than normal increase in CMAP amplitude occurred during and after exercise, whereas in proximal myotonic myopathy a normal initial increase in CMAP amplitude was followed by an abnormal decrement. We conclude that the ET can be of use in confirming abnormal muscle membrane excitability in patients with calcium and sodium channelopathies and thyrotoxic periodic paralysis. In chloride channelopathy, the test may also be abnormal, but shows no, or only a small, increase in amplitude or area in the immediate postexercise period. The test may also be abnormal in proximal myotonic myopathy, but is normal in myotonic dystrophy.     

Integrated electrical activity and number of zero crossings during a gradual increase in muscle force in patients with neuromuscular diseases

In the brachial biceps muscle of 17 patients with myopathy and of 14 patients with neurogenic disorders the integrated electrical activity and number of zero crossings per unit time were analysed in 3 sites of each muscle every 100 msec during a gradual increase in force from zero to maximum within 10 sec. The analysis of integrated electrical activity could not discriminate between patients with myopathy and patients with neurogenic disorders. The slope of the linear relation between the square root of integrated electrical activity and force expressed in kilograms was increased in 44% of the patients with myopathy and in 64% of the patients with neurogenic disorders. The increase in slope may be due to increase in the ratio of electrical activity and force of individual motor units. The integrated electrical activity related to a force of 40% of maximum was decreased in about two-thirds of patients with myopathy and in about half of the patients with neurogenic disorders. This decrease in integrated electrical activity may be due to random loss of muscle fibres or to loss of whole motor units respectively. The integrated electrical activity was linearly related to mean amplitude between potential reversals per unit time (turns). The number of zero crossings was increased in 29% of the patients with myopathy and decreased in 70% of the patients with neurogenic disorders at a force of 30% of maximum. The number of zero crossings was linearly related to turns.(ABSTRACT TRUNCATED AT 250 WORDS)     

MYOPATHY AND NEUROPATHY ASSOCIATED WITH OSTEOMALACIA

Thirty unselected females with proven osteomalacia were evaluated clinically, electromyographically and histopathologically for muscle dysfunction. Clinical evidence of myopathy was found in all the patients except one; the electromyograms were abnormal in 25 of them, and histopathological abnormalities, although slight and nonspecific, were seen in all the 17 patients who underwent muscle biopsy. Electromyographic findings revealed a myopathic pattern as evidenced by a significant reduction in motor unit potential duration and amplitude, and an increased percentage polyphasicity as compared to the controls. There was a complete absence of denervation potentials. The histopathological abnormalities were nonspecific and slight, and consisted of fatty infiltration, interstitial fibrosis, sarcolemmal nuclear proliferation and variation in muscle fibre thickness. A statistically significant reduction in motor nerve conduction velocities of the ulnar and peroneal nerves was found. It was considered that this reduction in the velocities was due to subclinical neuropathy. Our data suggest that myopathy, neuropathy and osteomalacia in our patients are due to nutritional deficiencies of multiple vitamins.     

Simulation and analysis of the electromyographic interference pattern in normal muscle. Part I: Turns and amplitude measurements

The electromyographic (EMG) interference pattern (IP) was simulated by adding together motor unit action potentials (MUAPs) of different sizes that had been recorded by a concentric needle EMG electrode. The number of turns (NT) of the simulated IP increased with the number of MUAP discharges. The mean amplitude (MA) difference between successive turns in the IP increased when large amplitude MUAPs were added. Our analysis demonstrates that the MA of the IP is determined mainly by the amplitude of large MUAPs in the signal and that large amplitude spikes are more likely to be generated by single large amplitude MUAPs than by summation of several small amplitude MUAPs.