重症肌无力单纤维肌电图测定

57例MG患者和40例健康正常人分别进行了SFEMG检查,部分患者同时进行重复电刺激和SFEMG进行比较。结果发现:MG患者SFEMG阳性率为82.5％。按MG分型:眼肌型阳性率为58.3％,全身型阳性率为100％。而重复电刺激阳性率仅为64％。同时SFEMG的个体MCD均值大小及Jitter阻滞率与病程无关,与病型和病情有关。SFEMG是诊断MG敏感的电生理检查方法。     

重症肌无力患者病情变化对单纤维肌电图jitter值的影响

目的:探讨重症肌无力(MG)病情变化和单纤维肌电图(SFEMG)颤抖(jitter)值变化之间的关系。方法:对MG患者治疗前后的病情进行绝对评分并计算相对评分,同时行SFEMG检查,统计分析相对评分和jitter值变化率之间的关系。结果:MG患者随病情好转或痊愈,jitter值相应变小,病情变化和jitter值变化率总体呈弱相关(非Ⅰ型MG患者相关参数r=0.617、R2=0.380、P=0.008)。结论:病情的变化影响jitter值,但jitter值的改变不能及时反应病情的变化,对于预测病情的转归帮助有限。     

重症肌无力患者单纤维肌电图与低频重复电刺激测定的对比研究

通过对４６例确诊的重症无力（ＭＧ）患者进行低频重复电刺激（ＬＦＲＮＳ）和单纤维电图（ＳＦＥＭＧ）的对比研究，部分病便还作了常规同心针极肌电图（ＣＮＥＭＧ）检查。发现ＬＦＲＮＳ阳性率为５７％。受检的三组肭肉中三角肌阳性率最高（４８％）。ＳＦＥＭＧ阳性率为９１％，其中轻型（改良Ｏｓｓｅｒｍａｎ分型中Ⅰ、Ⅱ、Ⅲ）为８８％，重型（Ⅱ、Ⅲ、Ⅳ、和Ⅴ型）为１００％，两种检查阳性率有显著性差异（Ｐ〈０．０１）。     

重症肌无力I型患者单纤维肌电图及呼吸肌功能的研究

通过对１８例确诊的ＭＧＩ型患者ＳＦＥＭＧ和呼吸肌功能的测定，发现Ｉ型患者ＳＦＥＭＧ（Ｊｉｔｔｅｒ）阳性率３８．９％（７／１８），未见Ｊｉｔｔｅｒ阻滞；６６．７％（１２／１８）的患者有不同程度的呼吸肌功能损害。     

单纤维肌电图结合疲劳试验对重症肌无力的诊断价值

目的对重症肌无力(MG)患者行单纤维肌电图(SFEMG)检测及疲劳试验,探讨两者结合对重症肌无力的诊断意义。方法选择53例MG患者进行试验。均在下午15点~16点选取小指展肌、三角肌进行SFEMG检测,休息10min后,进行疲劳试验5min,休息2min后再进行SFEMG检测记录相关数据进行分析。结果 53例患者中,单纯SFEMG检查正常者20例(33.73%),异常者33例(62.26%),其中颤抖延长者有34例(64.15%),阻滞者28例(52.83%)。疲劳试验后,SFEMG检查正常者3例(5.66%),异常者50例(94.34%),其中颤抖延长者有48例(90.57%),阻滞者43例(81.13%)。疲劳试验前后两者数据相比,差异有统计学意义(P<0.05)。结论 SFEMG结合疲劳试验可明显提高MG患者的阳性诊断率,尤其对于静息状态下SFEMG检测正常的MG患者更有效,能在检测中很好的减少伪差,减小患者重复检查的痛苦,并对记录结果的分析有很高的参考价值。     

Jitter测定在评价重症肌无力病情严重程度中的意义

目的:探讨Jitter值对判断重症肌无力(MG)病情及预后的意义。方法:运用单纤维肌电图(SFEMG)技术对49例不同病情、病型及治疗的MG患者进行Jitter值测定,同时测定每一例的临床绝对评分。结果:(1)临床绝对评分、Jitter各指标与病型均有关,且Jitter各指标对区分眼型(Ⅰ)和全身型(Ⅱ)有所帮助;(2)MG患者个体MCI)均值、＞55μs电位对百分比及阻滞电位对百分比与临床绝对评分之间呈显著负相关(P＜0.001),而正常电位对百分比与临床绝对评分之间存在显著正相关(P＜0.001);(3)病程与Jitter各指标之间均无相关性(P＞0.05);(4)短期随访经激素治疗或手术治疗后乙酰胆碱受体抗体(AChRab)有转阴趋势,而SFEMG和低频重复电刺激检查结果转阴趋势不明显。结论:Jitter值测定是一项评价重症肌无力病情严重程度较为客观、准确的技术。     

Jitter测定在评价重症肌无力病严重程度中的意义

目的：探讨ＪＩｉｔｔｅｒ值对判断重症肌无力（ＭＧ）病情及预后的意义。方法：运用单纤维肌电图（ＳＦＥＭＧ）技术对４９例不同病情、病型及治疗的ＭＧ患者进行Ｊｉｔｔｅｒ值测定,同时测定第一例的临床绝对评分。结果：（１）临床绝对评分、Ｊｉｔｔｅｒ各指标与病型均有关,且Ｊｉｔｔｅｒ各指标对区分眼型（Ⅰ）和全身型（Ⅱ）有所帮助;（２）ＭＧ患者个体ＭＣＤ值均、〉５５μｓ电位对百分比及阻滞电位对百分比与临床绝对评     

单纤维肌电图在眼肌型重症肌无力中的应用(附80例报告)

目的　研究眼肌型重症肌无力 ( OMG)患者的单纤维肌电图 ( SFEMG)及与其他辅助检查的关系 ,期望对临床诊断提供帮助。方法　对 80例 (男 39例 ,女 4 1例 ) OMG患者低频和高频重复神经电刺激 ( RNS)、伸指总肌 (部分额肌 ) SFEMG和血中乙酰胆碱受体抗体 ( ACh RAb)进行测定。结果　伸指总肌 SFEMG示 ,5 0例( 6 2 .5 % )异常 ,表现为颤抖增宽和阻滞。平均颤抖为 ( 4 5 .2± 2 1 .0 )μs,颤抖 >5 5μs所占百分比为 ( 1 8.2± 2 6 .5 ) ,阻滞所占百分比为 ( 8.7± 1 5 .3)。额肌 SFEMG示 ,8例 ( 80 % )异常 ,平均颤抖为 ( 6 6 .3± 2 6 .8)μs,颤抖 >5 5μs所占百分比为 ( 32 .7± 2 8.5 ) ,阻滞所占百分比为 ( 2 8.0± 2 4 .3) ,明显高于正常对照组 ( P<0 .0 0 1 )。 RNS异常率为 2 8.8% ( 2 3/80 )。 ACh RAb滴度增高占 38.8% ( 2 6 /6 7)。 SFEMG的颤抖和阻滞与 RNS递减的程度呈明显的负相关性。 RNS和 ACh RAb异常组平均颤抖明显高于正常组 ( P<0 .0 0 1 )。但 SFEMG正常组仍有 1 3.3% ( 4 /30 ) RNS异常和 2 6 .7% ( 8/30 ) ACh RAb异常。结论　SFEMG在 OMG患者的辅助检查中阳性率最高 ,与 RNS和 ACh RAb具有互补作用 ,三者结合可有助于 OMG的诊断。     

重症肌无力常规针极肌电图表现

目的 研究重症肌无力(MG)患者常规针极肌电图(EMG)表现及其诊断价值.方法 回顾性分析83例完成右侧三角肌针极EMG、腋神经低频重复电刺激(RNS)和伸指总肌单纤维肌电图(SFEMG)检查的MG患者的有关资料,分析针极EMG的表现及其与RNS的相关性.结果 83例中EMG检查结果正常12例(14.5%),异常71例(85.5%).在EMG异常者中,出现平均运动单位电位(MUAP)时限缩短67例(94.4%),多项波增多者37例(52.1%),大力收缩时募集电位呈病理干扰相19例(26.8%),异常自发电位3例(4.2%),结果符合"肌源性损害"表现19例(26.8%).腋神经RNS时三角肌波幅衰减幅度与三角肌平均MUAP时限呈负相关.结论 MG患者常规EMG检查主要异常表现为MUAP时限缩短,少数可见"肌源性损害"的EMG表现.对于临床表现不典型的MG患者应检查EMG并结合RNS和SFEMG检查进行诊断和鉴别诊断.     

胆碱酯酶抑制剂对重症肌无力电生理学检查结果的影响

目的探讨胆碱酯酶抑制剂对重症肌无力(myasthenis gravis,MG)电生理学检查结果有无影响。方法对53例MG肌注新斯的明1.5 mg,每例均在注射前后依次进行临床绝对评分、右侧伸指总肌的单纤维肌电图(single fiber electromyography,SFEMG)和左侧桡神经低频重复电刺激(repetitive nerve stimulation,RNS)检查,比较用药前后各项指标的变化。结果发现用药前后SFEMG中平均颤抖(jitter)、异常电位对和阻滞电位对的比例均无统计学差异(P>0.05);与此同时用药后RNS波幅递减的幅度和临床绝对评分均较用药前显著降低(P均为0.000)。结论胆碱酯酶抑制剂对MG的SFEMG的各项指标均无明显影响,而能显著改善RNS结果和临床症状的评分。     

胸腺切除术对重症肌无力患者电生理学指标和临床评分的影响

目的评价胸腺切除术对重症肌无力(MG)的近期疗效。方法对15例MG在胸腺切除术前(平均9天)及术后(平均11天)依次进行了临床绝对评分、右侧腋神经低频重复电刺激(RNS)和右侧伸指总肌单纤维肌电图(SFEMG)检查。结果手术后SFEMG和RNS异常率分别为100%和73%,手术后平均颤抖(jitter)值、异常电位对比例、阻滞电位对比例和临床绝对评分都较手术前有显著的降低;病理为胸腺瘤5例,手术前后平均jitter值、阻滞电位对比例和临床绝对评分均无显著差异,胸腺增生9例,手术后阻滞电位对比例和临床绝对评分较术前显著减低。结论MG患者胸腺切除术后在临床表现和电生理学指标上都有一定程度的改善,但此时大多数患者仍有临床症状和电生理学指标的异常,需要进一步的免疫调节治疗;MG并发胸腺瘤者可能手术后近期疗效差,并发胸腺增生者可能疗效相对较好。     

重症肌无力患者Jitter值及肌纤维密度测定研究

运用单纤维肌电图（SFEMG）技术对49例重症肌无力（MG）患者和35例正常人进行了Jitter值、肌纤维密度（FD）值测定，同时结合低频重复电刺激（IFRNS）、烟碱型乙酰胆碱受体抗体（nAchRab）测定作了对比研究。结果显示:MG患者的Jitter明显增宽（P＜0.01）;SFEMG检出MG比LFRNS与nAchRab测定阳性率高（P＜0.05），而且发现临床尚未出现肌无力症状的肌肉中也存在潜在的神经肌肉传递障碍;MG患者FD值无明显增高（P＞0.05）。从而提示，Jitter测定对诊断MG是一项敏感性较高的电生理技术，FD测定可作为区分MG患者与其它神经肌肉疾病患者Jitter异常的一个良好指标。     

Single fiber EMG as a prognostic tool in myasthenia gravis

Introduction: Single fiber electromyography (SFEMG) is the most sensitive diagnostic tool for diagnosis of myasthenia gravis (MG). Its prognostic value is not known. Methods: We retrospectively analyzed the clinical course of 232 MG patients who presented with only mild symptoms and had SFEMG of the orbicularis oculi muscle. We correlated their SFEMG results with the severity of their later clinical course. Results: During the observation period 39 patients (17%) developed severe disease exacerbations, and 193 (83%) remained stable. Patients with severe disease exacerbation had a significantly higher mean jitter value (P < 0.0001), a greater percentage of fibers with increased jitter (P < 0.0001), and/or impulse blocking (P < 0.0001) on SFEMG. Conclusions: The extent of the SFEMG abnormalities in this study correlated with the later clinical course of MG. Muscle Nerve 54 : 1034–1040, 2016     

Single fiber EMG and repetitive stimulation of the same muscle in myasthenia gravis

We performed RNS and SFEMG studies of the same muscle in 46 patients with myasthenia gravis. Maximum decrement to 3–5-Hz stimulation before and after maximum voluntary exercise, percentage of action potential pairs with increased jitter and blocking, and mean MCD in each study were compared. A significant decrement (> 10% decrease in CMAP area or amplitude between the first and fourth response) was never found without increased jitter and impulse blocking on SFEMG. Increased jitter, blocking, and mean MCD were each correlated with maximum decrement (r > 0.61, P < 0.0001). We conclude that decrement to RNS and impulse blocking on SFEMG result from the same physiologic phenomenon, and that SFEMG is more sensitive at detecting disordered neuromuscular transmission given its ability to detect impulse blocking at levels below the resolution of RNS and increased neuromuscular jitter when there is not blocking. © 1994 John Wiley & Sons, Inc.     

Ocular myastyenia gravis: The diagnostic yield of repetitive nerve stimulation and stimulated single fiber EMG of orbicularis oculi muscle and infrared reflection oculography

For the diagnosis of ocular myasthenia gravis (ocular MG), testing of the muscles close to the affected ones may be important. The relative importance of several methods: stimulated single fiber EMG (stimulated SFEMG), repetitive nerve stimulation test (RNS) of orbicularis oculi muscle, and infrared reflection oculography (IROG) was investigated. Thirty-two patients in whom a diagnosis of ocular MG was considered on clinical grounds were admitted to the study. Based on the results of the three neurophysiological tests, the patients could be divided in three groups: a first group with an abnormal stimulated SFEMG, and an abnormal RNS and/or abnormal IROG; a second group with only a slightly abnormal stimulated SFEMG; and a third group with normal tests in all three tests. The clinical diagnosis of ocular MG was made in all 11 patients of the first group; in 86% (6 of 7) of the patients of the second group; and in 7% (1 of 14) of the patients of the third groups. This study demonstrates that the orbicularis oculi muscle is a suitable muscle for stimulated SFEMG in patients with ocular MG, and that the results obtained with this technique showed a better relation with the clinical diagnosis than those of the two other techniques. We also demonstrate that there is no additional value in studying the jitter with different stimulation rates in patients with suspected ocular MG. © 1993 John Wiley & Sons, Inc.     

Single fiber EMG in the frontalis muscle in ocular myasthenia: specificity and sensitivity.

Patients (n = 41) with isolated weakness of the eyelids or extraocular muscles, who had been referred for single fiber electromyography (SFEMG), were followed up after 4 to 24 months, At follow-up the patients were classified as "definite ocular myasthenia gravis" (MG), "definite other diagnosis," or "no definite diagnosis" on the basis of the completed investigations and subsequent course. The original SFEMG findings in the frontalis muscle were then reviewed. The specificity and sensitivity of SFEMG for "definite ocular MG" could be maximized by using as criteria for abnormality greater than 8/20 pairs with jitter greater than 45 microseconds, or a mean jitter of 20 pairs of greater than 50 microseconds. Patients with abnormal SFEMG according to these criteria have MG, and are likely to require treatment in the immediate future. Patients who have normal SFEMG according to these criteria (and no other demonstrated disorder) may have MG, but it is so mild that they are unlikely to require treatment. Two patients whose final diagnosis was progressive external ophthalmoplegia had normal SFEMG according to these criteria.