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。     

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.     

重症肌无力患者眼轮匝肌单纤维肌电图检测

目的 探讨重症肌无力患者眼轮匝肌单纤维肌电网(SFEMG)检查的临床应用价值.方法 40例重症肌无力患者(眼肌型27例,全身型13例)分别接受眼轮匝肌单纤维肌电图[以平均颤抖值>正常值上限、>10%单个肌纤维对颤抖增宽(>55μs)、伴或小伴阻滞作为异常颤抖判断标准]和面神经重复神经电刺激(RNS)检查(以复合肌肉动作电位衰减>15%作为异常动作电位判断标准),比较两种电生理学检查方法的阳性检出率、敏感性和特异性,以及SFEMG测值与重症肌无力分型之间的关系.结果 重症肌无力患者眼轮匝肌平均颤抖值为(76.42±24.59)μs,颤抖增宽电位对比例(69.01±26.66)%,阻滞电位对比例(46.62±27.41)%,与对照组比较差异具有统计学意义(均P<0.05).SFEMG阳性检出率为82.50%(33/40),高于RNS(35%,14/40),差异具有统计学意义(P<0.05).SFEMG检查敏感度分别为82.50%和77.50%,特异度均为100%;RNS检查敏感度分别为27.50%和22.00%,特异度均为0.结论 眼轮匝肌单纤维肌电图是诊断重症肌无力较为敏感的电生理学检查方法,应用于临床时尚需与其他肌肉单纤维肌电图检查、重复神经电刺激检查及乙酰胆碱受体抗体试验相结合.     

重症肌无力患者单纤维肌电图测定及临床意义

对４５例重症肌无力患者进行单纤维肌电图测定，其中Ⅰ型１８，例ⅡＡ型和Ⅱ型２７例，结果Ｊｉｔｔｅｒ均值；Ⅱ型明显延长于Ⅰ型，Ⅱ型阳性率８８．９％，Ⅰ型阳性率３８．９；Ⅱ型Ｊｉｔｔｅｒ阻滞率４４．４％Ⅱ型未见阻滞电位。结合文献复习，认为ＳＦＥＭＧ是目前诊断ＭＧ是敏感的电生理检查方法，ＳＦＥＭＧ可帮助判断病情，对估计疗效和预后也有一定意义。     

眼轮匝肌刺激型单纤维肌电图在眼肌型重症肌无力的应用

目的建立眼轮匝肌刺激型单纤维肌电图(SFEMG)正常对照组的颤抖参考值, 并探索其应用于重复神经刺激(RNS)阴性眼肌型重症肌无力(OMG)患者的敏感度及其与各临床指标的关系。方法 2019年1—12月于中山大学附属第一医院神经科肌电图室招募健康志愿者32名, 以建立正常对照组的参考值。收集2019年12月至2023年1月中山大学附属第一医院RNS阴性的OMG患者36例。对患者进行定量MG评分(QMGS), 记录其新斯的明试验、抗体及胸腺CT结果。使用一次性同心圆针电极对一侧眼轮匝肌进行刺激型SFEMG检测, 计算平均连续波间期差(MCD), 与正常对照组的MCD平均值及单个值上限对比以评估颤抖是否异常。将均值异常的MCD值分别与QMGS和抗体滴度进行Spearman相关分析。结果 32名健康人中男性13名, 女性19名, 年龄(46.8±18.7)岁, MCD为(19.0±4.4)μs。所得MCD的参考值上限为平均27.7 μs, 单个37.4 μs, 超过平均值上限或单个值超过上限者占比超过10%为异常。36例OMG患者中男性20例, 女性16例, 年龄(37.2±17.0)岁, ...     

重症肌无力并多发性肌炎1例

1　病例介绍患者男性 ,14岁 ,学生。因“持续双下肢无力 2月”于2 0 0 3年 7月 31日入院。缘于 2 0 0 3年 5月份受凉后出现鼻塞、流涕 ,浑身无力 ,服用感冒通、牛黄解毒片后 ,病情好转 ,但双下肢无力仍存在 ,伴大腿肌肉酸痛 ,不能跑步 ,走路约 10 0米后出现劳累 ,爬楼梯及下蹲起立困难 ,读书时低头 10分钟后自觉头颈酸感 ,抬头费力。自诉晨起症状较轻 ,活动后加重 ,休息后症状可减轻。活动后心慌 ,心率可达 10 0次 /分以上 ,休息后缓解 ,遂到当地医院行肌酶谱检查示 :谷草转氨酶10 8.4U/L、乳酸脱氢酶 12 0 8.3U/L、羟丁酸脱氢酶10 0 1.5U…     

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。     

乙酰胆碱受体α亚单位125～147段多肽致实验性自身免疫性重症肌无力

目的　用多肽免疫动物建立实验性自身免疫性重症肌无力动物模型。方法　合成电鳗乙酰胆碱受体α亚单位Tα1 2 5～ 1 4 7片段 ,并用其免疫接种长耳白兔 ,观察接种动物的临床症状、抗体滴度及神经电传导功能变化。结果　实验兔强化接种后第 2～ 5天渐出现肌无力症状 ,新斯的明试验阳性。接种免疫原组抗多肽Tα1 2 5～ 1 4 7抗体吸光度 (0 745 8± 0 1 681 )远高于对照组 (0 1 2 79± 0 0 1 73 ,P <0 0 5) ,3、5、1 0Hz下重复神经电刺激实验 (RNS)动作电位衰减率和单纤维肌电图检查颤抖值 (MCD)均较对照组明显延长 (P <0 0 5)。结论　Tα1 2 5～ 1 4 7能作为免疫原诱导动物产生重症肌无力模型     

单纤维肌电图在30例炎性肌病患者诊断中的应用

目的研究单纤维肌电图(SFEMG)在炎性肌病患者诊断中的价值和与其他辅助检查的关系。方法对30例(男9例,女21例)炎性肌病[其中多发性肌炎(PM)20例,皮肌炎10例)]患者进行伸指总肌SFEMG测定,并与常规肌电图(EMG)、血清肌酸激酶(CK)的测定结果及肌肉病理检查结果进行对比。结果30例患者伸指总肌SFEMG测定均异常,主要表现为纤维密度(FD)增高,部分患者伴有轻度的颤抖增宽,仅1例伴有1处阻滞。FD为1～6,平均为2.33±0.45。颤抖值为5～78μs,平均(41.7±10.8)μs;颤抖>55μs者所占百分比为0%～55%。常规EMG表现为肌源性损害21例(70%),神经源性损害2例(6.7%),正常7例(23.3%)。血清CK增高20例。肌肉病理符合PM和DM诊断者13例。结论常规EMG和CK正常及病理未见特征性改变但临床疑诊炎性肌病者,SFEMG的检查为其诊断提供了客观依据。     

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）。     

Single-fiber EMG with a concentric needle electrode: validation in myasthenia gravis

We performed a retrospective study to validate whether a disposable concentric needle electrode (CNE) can be used in place of a single-fiber (SF) electrode for jitter measurements in myasthenia gravis (MG). Normal values for voluntary contraction of orbicularis oculi (OO) and extensor digitorum communis (EDC) were collected from 20 healthy subjects. The method was validated by a retrospective analysis of 56 consecutive MG patients, the "gold standard" being a positive acetylcholine receptor (AChR) antibody titer at the time of the electrophysiological (electromyography) study and the clinical diagnosis. Receiver operating characteristic (ROC) curves were constructed to define maximal sensitivity and specificity of the technique. The sensitivity was 96.4% (95% confidence interval 87.5%-99.6%), with no false-positive results, similar to traditional SF EMG and confirming that the disposable CNE is a justifiable alternative.     

Single fiber electromyography in myasthenia gravis during pregnancy

We report the use of single fiber electromyography (SFEMG) to demonstrate changes in the physiologic abnormality of myasthenia gravis (MG) during pregnancy. A 23-year-old became pregnant 15 months after the onset of mild ocular weakness. On initial evaluation, SFEMG jitter measurements demonstrated a slight abnormality of neuromuscular transmission. There was no change in severity of clinical disease or jitter measurements until the third trimester, when she improved. Jitter measurements at that time were normal. Labor was normal and she delivered a normal male. Three days postpartum, myasthenic weakness recurred temporarily and jitter measurements showed worsening. At 16 days and 6 weeks postpartum, she had only minimal medial rectus weakness and jitter studies were normal. Three months postpartum, ocular symptoms recurred and jitter measurements were slightly abnormal. She continued to worsen, developing limb muscle and severe ocular muscle weakness at 4 months postpartum. She was treated with plasma exchange and thymectomy. Prednisone was added 2 months after thymectomy due to continued worsening and development of oropharyngeal weakness. Three years postpartum she was taking prednisone 10 mg every other day and had only slight weakness of neck flexors, and jitter studies were again normal. © 1993 John Wiley & Soncs, Inc.     

Concentric-needle single-fiber electromyography for the diagnosis of myasthenia gravis

The goal of this study was to estimate the accuracy of concentric-needle single-fiber electromyography (CN-SFEMG) for the diagnosis of myasthenia gravis (MG). A consecutive series of patients referred for CN-SFEMG was evaluated by an investigator blinded to the results of CN-SFEMG in order to determine the presence or absence of MG using an independent reference standard. Sensitivity, specificity, predictive values, and likelihood ratios were calculated. The study population included 51 patients (21 with MG). CN-SFEMG was normal in 34 patients (67%) and abnormal in 17 (33%). The sensitivity of CN-SFEMG for the diagnosis of MG was 0.67 and the specificity was 0.96. The positive likelihood ratio was 16.8 and the negative likelihood ratio was 0.34. The positive and negative predictive values were 0.93 and 0.76, respectively. These results indicate that CN-SFEMG showing abnormal jiggle is extremely useful for confirming the diagnosis of MG, but that CN-SFEMG showing normal jiggle has limited utility in excluding the diagnosis.     

Concentric needle jitter on stimulated frontalis and extensor digitorum in 20 myasthenia gravis patients

Introduction: Our objective was to study jitter parameters using a concentric needle electrode (CNE) in the extensor digitorum (ED) and frontalis (FR) muscles. Methods: Twenty myasthenia gravis (MG) patients, mean age 44.5 years, were studied. Percutaneous (FR) and intramuscular needle (ED) stimulation approaches were used. Jitter was expressed as the mean consecutive difference (MCD). The filter settings were from 1000 HZ to 10 kHZ . Results: Abnormal MCD was found in 85% for both ED and FR and in 90% when combining the two muscles. An abnormal percentage of outliers was found in 90% for ED and 85% for FR. The mean MCD did not show a difference for ED and FR, but the percentage of outliers and blocking were higher in FR. Abnormality was found in 93.7% (generalized) and in 75% (ocular) of MG cases. For ED outliers abnormality was greater than the MCD. Conclusion: CNE jitter is reliable for investigation of MG, although borderline findings should be judged with caution. Muscle Nerve 2011     

Single-fiber electromyography in experimental autoimmune myasthenia gravis

The sensitivity of stimulated single-fiber electromyography in the detection of early abnormalities in neuromuscular transmission in experimental autoimmune myasthenia gravis (EAMG) was tested. Increased jitter and blocking were seen up to 3 weeks before clinical illness or decrement developed. Stimulation at 10 Hz appeared more sensitive in detection of abnormalities than stimulation at 3 or 5 Hz. Jitter values did not correlate with anti-Torpedo acetylcholine receptor (AChR), nor with anti-rat AChR antibody titer. No correlation was found between jitter and AChR loss or AChR-antibody complexes in muscle. It is concluded that, in addition to AChR loss and the presence of AChR-antibody complexes, other factors must determine the neuromuscular dysfunction in EAMG and possibly myasthenia gravis.     

Evaluation of neuromuscular transmission by using monopolar needle electrode

OBJECTIVE: To evaluate the value of single-fibre electromyography (SFEMG) with monopolar electrode (MNPE) in revealing neuromuscular transmission dysfunction. MATERIAL AND METHODS: We examined the extensor digitorum communis muscle by using single-fibre electrode (SFE) and MNPE sequentially, in randomly assigned 20 healthy volunteers and in 17 patients with known myasthenia gravis (MG). The high-pass filter setting was 3 kHz for MNPE. Ten individual jitter values were calculated for each electrode in every muscle. Repetitive nerve stimulation (RNS) test on trapezius muscle was performed on 15 patients. RESULTS: In controls, the mean jitter values were 27 +/- 9 (10-59) micro s with SFE, and 21 +/- 7.2 (9-56) micro s with MNPE (P = 0.001). In the MG group, the mean jitter values were 52.4 +/- 38 (12-221) micro s with SFE, and 51.8 +/- 34.7 (12-179) micro s with MNPE. Both electrodes identified junction dysfunction in 14 patients. RNS revealed decrement in four patients but 11. CONCLUSION: SFEMG with SFE is still the gold standard; however, SFEMG with MNPE is superior to RNS like SFEMG with SFE.     

Diagnostic yield of stimulation and voluntary single-fiber electromyography in myasthenia gravis

Voluntary and stimulation single-fiber electromyography were performed in the extensor digitorum communis muscle of 15 myasthenic patients. The increase in mean and individual mean consecutive difference as well as the proportion of blocking in the volitional activation were greater than in the stimulation method. These differences may be explained in part by the different degree of alteration in large as compared with small motor units in patients with myasthenia gravis. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:1081–1083, 1998.     

Single-fiber electromyography in limb and facial muscles in muscle-specific kinase antibody and acetylcholine receptor antibody myasthenia gravis

We examined the findings from single-fiber electromyography in extensor digitorum communis (EDC) and orbicularis oculi (OOc) in 13 myasthenia gravis (MG) patients with muscle-specific kinase antibodies (MuSK-MG) and 12 MG patients with acetylcholine receptor antibodies (AChR-MG) with similar clinical scores. More than 70% of AChR-MG patients had abnormal jitter in both EDC and OOc, but the majority of MuSK-MG patients had normal jitter in EDC despite abnormal jitter in OOc. These findings demonstrate clear differences between the neurophysiology of MuSK-MG and AChR-MG.