眼轮匝肌睑部重复电刺激在眼肌型重症肌无力诊断中的价值研究

目的探讨不同面神经支配肌尤其是眼轮匝肌睑部重复电刺激(RNS)在眼肌型重症肌无力(MG)的诊断价值。方法分析61例眼肌型MG患者,比较不同面神经支配肌RNS阳性率。结果额肌的RNS阳性率为8.47%(5/59例),眼轮匝肌睑部疲劳试验前RNS阳性率为73.77%(45/61例),疲劳试验后RNS阳性率提高至88.52%(54/61例);眼轮匝肌眶部和鼻肌的RNS阳性率分别为50.82%(31/61例)和42.62%(26/61例)。眼轮匝肌睑部RNS阳性率高于其他面神经支配肌(P=0.000~0.009),且疲劳试验后RNS阳性率高于疲劳试验前(P=0.037)。结论眼肌型MG患者眼轮匝肌睑部RNS阳性率高于其他面神经支配肌,疲劳试验可进一步提高其阳性结果 。     

MuSK抗体阳性重症肌无力10例临床分析

目的探讨骨骼肌特异性酪氨酸激酶(muscle-specific tyrosine kinase,MuSK)抗体阳性重症肌无力(MuSK-myasthenia gravis,MMG)临床特点和对治疗的反应。方法分析2017年7月至2018年12月就诊于我院的MG患者的临床资料,计算MMG占全部MG患者比例,并对MMG患者的起病年龄,起病方式,临床进展模式和对治疗的反应进行分析,并随访至少6个月,每3个月电话或面对面随访记录患者日常生活能力评分(myasthenia gravis-activity of daily living score,MG-ADL)。结果401例MG患者中,完成MuSK检测319例,MuSK抗体阳性率为3.13%(10/319)。10例MMG患者男女比为1:9,起病年龄17耀50岁,平均31.4岁。90%患者以眼外肌无力为首发症状。1年内进展为全身型的比例高达90%。溴吡斯的明有效率90%,重频刺激低频递减阳性率为77.78%,无胸腺异常者。经过至少6个月的随访,大多数患者ADL评分降至0耀1分。结论眼动障碍和球部肌无力为这组患者突出的临床表现,免疫治疗有效。     

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.     

AChR及MuSK双抗体阳性重症肌无力三例并文献复习

目的报道3例乙酰胆碱受体(AChR)抗体和肌肉特异性酪氨酸激酶(MuSK)抗体双抗体阳性重症肌无力(myasthenia gravis,MG)患者的临床特点、诊疗和预后,并复习既往相关文献,以提高对这一特殊MG类型的认识。方法对作者医院3例AChR及MuSK双抗体阳性的确诊MG病例进行报道,并检索近20年Medline和万方中文数据库,选择国内外报道的上述双抗体阳性的确诊MG病例中包含临床特点、实验室检查及诊疗结果的文章,结合作者医院病例分析和总结AChR及MuSK双抗体阳性MG的临床特点及诊治情况。结果8篇文献中的7例MG,包括作者医院的3例,共10例AChR及MuSK双抗体阳性MG纳入分析,男4例、女6例,平均起病年龄(45.5±24.1)岁,起病症状包括眼睑下垂到呼吸困难轻重不等,受累肌群可包括眼外肌(9/10)、球部肌肉(9/10)、颈肌(7/10)、四肢肌(8/10)和呼吸肌(6/10),肌无力危象发生率高(5/10)。9例行肌电图检查,8例重复电刺激(RNS)阳性,4例行单纤维肌电图(SFEMG)检测者均为阳性。双抗体阳性可在发病之初即为双阳性,也可在AChR抗体阳性基础上随着病情进展而发展形成,多在病情加重时出现,病情好转后亦可出现抗体转阴。溴吡斯的明+免疫抑制剂治疗对多数患者有效(8例中4例有效、4例部分有效);4例患者肌无力危象时使用血浆置换(PE)、2例重症患者使用利妥昔单抗治疗均有效,2例患者使用环孢素治疗,其中1例有效,2例患者硫唑嘌呤治疗均无改善。结论双抗体阳性MG患者任何年龄均可发病,女性居多,总体受累范围广,病情重,免疫抑制剂治疗个体差异大,PE对于危象效果好,双抗体表达情况随病情动态波动。     

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.     

我国华南地区MuSK抗体阳性重症肌无力患者的临床特点

目的分析我国华南地区骨骼肌特异性酪氨酸激酶抗体(MuSK-Ab)阳性重症肌无力(myasthenia gravis,MG)的临床特点。方法回顾性收集2017年8月至2019年8月在中山大学附属第一医院确诊的住院MuSK抗体阳性MG(MuSK-MG)患者26例,并选取同期收治的乙酰胆碱受体抗体(AChR-Ab)阳性MG(AChR-MG)患者157例作为对照组,比较两组患者临床特点以及对治疗反应的差异。结果与AChR-MG患者比较,MuSK-MG患者女性构成(80.8%比58.0%,P<0.05)、平均发病年龄〔(43.12±13.02)岁比(36.04±17.97)岁,P<0.05〕高,球部肌受累(96.2%比70.1%,P<0.01)和肌无力危象(myasthenic crisis,MC;61.4%比28.7%,P<0.05)更常见。两组患者新斯的明试验阳性率(61.5%比70.7%)、低频重复神经电刺激(RNS)阳性率(78.3%比83.3%)比较差异无统计学意义(均P>0.05)。在治疗反应方面,胆碱酯酶抑制剂(AChEIs)对MuSK-MG患者的有效率低于AChR-MG患者(16.0%比58.6%,P<0.01)。两组患者发生MC期间,对血浆置换(PLEX)的反应优于静脉注射丙种球蛋白(IVIG)。结论我国华南地区MuSK-MG以40岁左右女性多见,与AChR-MG比较易累及球部肌和呼吸肌,容易发生MC。MuSK-MG对AChEIs的反应性低于AChR-MG。RNS对我国华南地区MuSK-MG诊断的敏感性与AChR-MG比较无统计学差异,但高于欧美人群。PLEX在MuSK-MG患者的危象前或危象状态中的应用可显著缓解病情。     

面肌痉挛神经电生理检查的临床诊断意义

我科1996年5月以来,对来诊主诉面肌抽动患者138例进行面神经的肌电位活动及诱发肌电位活动检查,探讨面神经电生理检查对面肌痉挛的诊断和鉴别诊断的临床应用性和价值。现报道如下。资　　料对象　面肌抽动患者138例,其中男性58例,女性80例;年龄30～75岁,平均505岁;病程1个月～30年,平均474个月。根据临床主诉和症状特征分为典型组、非典型组和正常对照组。典型组为以一侧眼轮匝肌抽搐发作起病,逐步发展至颊部、口角联同抽动(包括仅一侧眼轮匝肌的抽动)[1,2],又称原发性面肌痉挛114例(其中12例单纯一侧眼轮匝肌抽动);非典型组指除了典型组以…     

不典型眼肌型重症肌无力的临床特点

目的研究不典型眼肌型重症肌无力(OMG)的临床特点。方法回顾性分析29例不典型OMG患者的临床资料。结果本组患者表现为上眼睑下垂3例,单眼1条眼外肌瘫痪15例,双眼3条眼外肌瘫痪1例,单眼全部眼外肌瘫痪1例,辐辏障碍2例,单眼眼轮匝肌瘫痪1例,类似眼病表现6例(复视4例、眼部不适和视物模糊2例,均无眼外肌瘫痪);有晨轻暮重表现12例(41.4%)。新斯的明试验阳性26例(89.7%),低频重复神经电刺激阳性8例(27.6%),单纤维肌电图(SFEMG)异常23例(79.3%)。患者早期均被误诊。经泼尼松和/或胆碱酯酶抑制剂治疗,症状消失26例(89.7%),显著改善3例(10.3%)。结论不典型OMG患者的临床特点为受累眼肌少,症状局限,表现晨轻暮重的比率低。新斯的明试验和SFEMG检查可确诊。     

眼肌型重症肌无力临床分析

目的总结分析眼肌型重症肌无力患者的临床特征,以为诊断和治疗提供参考依据。方法回顾性分析113例眼肌型重症肌无力患者的临床资料。采用免疫荧光细胞染色方法检测血清乙酰胆碱受体(AChR)抗体和肌肉特异性受体酪氨酸激酶(MuSK)抗体表达水平,分析这两项免疫学指标对眼肌型重症肌无力向全身型转化的预测价值。结果成年发病的眼肌型重症肌无力好发于40岁以上男性,多以眼睑下垂(95例,84.07%)为首发症状,少数以复视(18例,1 5.93%)起病。疲劳试验和新斯的明试验阳性率分别为79.44%(85/107)和84.85%(84/99),低频重复神经电刺激和血清甲状腺抗体异常率分别为44.32%(39/88)和28%(14/50),胸腺增生和胸腺瘤阳性率分别为16.67%(17/102)和11.76%(12/102);血清AChR抗体阳性率为62.83%(71/113);但MuSK抗体均呈阴性。眼肌型重症肌无力向全身型转化率为12.39%(14/113),其中血清AChR抗体强阳性者(13例,28.26%)显著高于弱阳性者(1例,4%),二者差异有统计学意义(X~2=4.587,P=0.032)。结论成年发病的眼肌型重症肌无力好发于中年以上男性,主要表现为眼睑下垂和复视,大多数患者伴发胸腺和甲状腺异常。血清AChR抗体表达水平升高预示向全身型转化率升高,鲜有MuSK抗体阳性反应。     

重症肌无力患者低频重复神经电刺激的特点

目的研究重症肌无力(myasthenia gravis,MG)患者低频重复神经电刺激(repetitive nerve stimulation,RNS)的特点。方法回顾性分析1995-2010年作者医院住院的275例MG患者的低频RNS检查资料。结果 275例患者中RNS检查结果异常216例,异常率为78.55%。其中Ⅰ型RNS异常率最低(48.91%),且与其他临床分型异常率之间存在统计学差异(P<0.05)。刺激腋神经RNS异常率最高(58.68%),面神经次之(56.18%),尺神经最低(18.88%)。在眼轮匝肌和三角肌进行记录时所测得的RNS异常率高于在小指展肌所测(P<0.01)。结论 MG患者RNS异常率与临床分型及检测部位有关。Ⅰ型患者RNS异常率低于其余各分型,于近端肌肉记录时所测的RNS异常率明显高于在远端肌肉所测。     

Repetitive nerve stimulation of facial muscles in MuSK antibody-positive myasthenia gravis

To better define electrophysiological abnormalities in myasthenia gravis (MG) patients with muscle-specific tyrosine kinase (MuSK) antibodies (Ab), we compared electrophysiological features of 14 MuSK Ab-positive, 73 acetylcholine receptor antibody (AChR Ab)-positive, and 22 MuSK and AChR Ab-negative (seronegative) patients with generalized disease. Repetitive nerve stimulation (RNS) abnormalities were observed in 86% of MuSK Ab-positive and 82% of AChR Ab-positive patients but in only 55% of seronegative patients. RNS decrements in the orbicularis oculi were more common and severe in the MuSK Ab-positive patients than the other two groups. Single-fiber electromyography (SFEMG) of the extensor digitorum communis was abnormal in 90% of MuSK Ab-positive patients. The high frequency of RNS abnormalities in facial muscles in the MuSK Ab-positive population reflects the propensity for facial muscle involvement in this form of MG and emphasizes the importance of including facial muscles in RNS protocols when evaluating these patients.     

Quantitative EMG of facial muscles in myasthenia patients with MuSK antibodies.

OBJECTIVE: Our aim was to study the pathophysiological process leading to facial muscle atrophy in 13 patients with MuSK antibody positive myasthenia gravis (MuSK-MG), and to compare with findings from 12 acetylcholine receptor antibody positive myasthenia patients (AChR-MG), selected because they suffered from the same degree of disease severity and required similar treatment. METHODS: Motor unit action potential (MUAP) and interference pattern analysis from orbicularis oculi (O oculi) and orbicularis oris (O oris) muscles were studied using a concentric needle electrode, and compared with findings in 20 normal subjects, 6 patients receiving botulinum toxin injections (representing a neurogenic model) and 6 patients with a muscle dystrophy (representing a myopathic model). The techniques and control data have been reported previously. RESULTS: The mean MUAP durations for O oculi and O oris were significantly reduced (p<0.001) in both MG cohorts when compared with healthy subjects, and were similar to those in the myopathic control group. They were significantly different from those obtained from the neurogenic control group (p<0.001 for both O oculi and O oris). The MUAP findings in O oculi occurred independently from neuromuscular blocking on single fibre EMG (SFEMG) in the same muscle. On turns amplitude analysis (TAA), 50% of MuSK-MG patients and 42% of AChR-MG patients had a pattern in O oculi which was similar to that in the myopathic control group, and 62% of MuSK-MG patients and 50% of AChR-MG patients had a pattern in O oris that was also similar to that in the myopathic control group. The TAA findings for O oculi and O oris in both MG cohorts were different from those obtained from the neurogenic control group. CONCLUSIONS: Facial muscle atrophy in MuSK-MG patients is not neurogenic and the pathophysiological changes are akin to a myopathic process. The selected AChR-MG patients also show evidence of a similar pathophysiological process in the facial muscles albeit to a lesser degree. SIGNIFICANCE: We propose that muscle atrophy in MuSK-MG is a myopathic process consisting of either muscle fibre shrinkage or loss of muscle fibres from motor units. The duration of disease and long-term steroid treatment may be further contributory factors.     

Repetitive hypoglossal nerve stimulation in myasthenia gravis.

OBJECTIVES: To assess the diagnostic efficacy of repetitive nerve stimulation (RNS) of the hypoglossal nerve in patients with myasthenia gravis (MG) and bulbar symptoms (dysphagia, dysarthria). METHODS: Twenty patients with MG and 25 normal controls had RNS of the hypoglossal nerve. All patients also had single fibre electromyography (SFEMG) of the orbicularis oculi and RNS with recordings of the nasalis, trapezius and abductor pollicis brevis muscles. RESULTS: All patients had positive SFEMG studies. Nine patients with bulbar symptoms had positive hypoglossal RNS, including 3 with negative RNS recordings in other muscles. Eleven patients with no bulbar symptoms showed negative hypoglossal RNS, including two with positive RNS recordings from other muscles. CONCLUSIONS: Abnormal RNS of the hypoglossal nerve correlates well with bulbar dysfunction and further characterises the extent of neuromuscular transmission defect in MG patients.     

肌肉特异性受体酪氨酸激酶抗体阳性重症肌无力

目的 探讨不同血清抗体重症肌无力(MG)的临床特征.方法 用荧光免疫沉淀法(FIPA)和荧光免疫细胞染色法(CBA)检测119例MG患者血清乙酰胆碱受体抗体(AChR-Ab)和肌肉特异性受体酪氨酸激酶抗体(MuSK-Ab)水平.比较AChR-Ab阳性、MuSK-Ab阳性、血清抗体阴性MG的临床特征.结果 纳入119例患者中,90例AChR-Ab阳性(75.6%),29例阴性:其中5例MuSK-Ab阳性(17.2%),24例血清抗体阴性(82.8%).AChR-Ab阳性、MuSK-Ab阳性和血清抗体阴性MG 3组比较,男女比例和平均发病年龄差异均无统计学意义.3例MuSK-Ab阳性的患者主要表现为延髓肌受累;79.2%(19/24)的血清抗体阴性MG患者表现为美国MG协会(MGFA)Ⅰ型;2例MuSK-Ab阳性的患者MGFA≥Ⅲ型;MuSK-Ab滴度水平与患者病情严重程度相关(r=0.941,P=0.014);MuSK-Ab阳性的患者均未发现有胸腺的异常.结论 MuSK-Ab仅出现在AChR-Ab阴性患者的血清中.MuSK-Ab阳性的患者主要表现为延髓肌受累,病情较重且不伴有胸腺的病变.MuSK-Ab阳性的MG可能是不同于血清AChR-Ab阳性的MG的又一亚型.     

Electrophysiological profile of the patients with MuSK positive myasthenia gravis

Abstract

Objectives:

To determine the electrophysiological profile of our cohort of patients with muscle-specific tyrosine kinase (MuSK) positive myasthenia gravis (MG).

Methods:

Repetitive nerve stimulation test (RNS) and jitter analysis using concentric needle electrode were performed in 31 MuSK and in 28 acetylcholine receptor (AChR) positive MG patients.

Results:

Pathological RNS was verified in 16 (51·6%) MuSK and 26 (92·9%) AChR MG patients (P < 0·01). Pathological jitter analysis was registered in 28 (90·3%) MuSK and 26 (92·9%) AChR MG patients (P > 0·05). Increased jitter was present in extensor digitorum communis (EDC) in 23 (74·2%) MuSK and in 25 (89·3%) AChR MG patients (P > 0·05) as well as in orbicularis oculi (OO) muscle in 24 (85·7%) MuSK and 22 (81·5%) AChR MG patients (P > 0·05). Lower mean value of mean consecutive difference (MCD) and fewer potential pairs with increased jitter were registered in MuSK MG compared to AChR MG patients only in EDC muscle (P < 0·05). In MuSK MG patients, increased jitter was observed to be more frequent in patients with longer disease duration (P < 0·05) and also in those patients exhibiting more severe disease forms (P < 0·01) only in EDC muscle.

Discussion:

Repetitive nerve stimulation test has low sensitivity in MuSK MG patients, while jitter analysis shows high sensitivity, especially in facial muscles. The EDC muscle in MuSK MG patients usually shows increased jitter in more severe disease forms and later in the course of the disease.     

Correlation between a patient-derived functional questionnaire and abnormal neuromuscular transmission in Myasthenia Gravis patients.

OBJECTIVE: To correlate the patient-derived physical function score, as measured by the disease specific Myasthenia Gravis Questionnaire (MGQ), and the score obtained with commonly used generic 36-item questionnaire, the Short-Form health survey (SF-36), with the degree of abnormal neuromuscular transmission measured by Single-Fibre EMG (SFEMG) and repetitive nerve stimulation (RNS) in Myasthenia Gravis (MG) patients. METHODS: SFEMG and RNS were performed in the deltoid muscle and SFEMG was also performed in the orbicularis oculi muscle in 45 MG patients. The patients were asked to fill out the MGQ, which has been translated and validated into Swedish, and the SF-36. The sum of MGQ items generates a global MGQ score. Items are also divided into 3 muscle specific domains: generalized, bulbar and ocular. RESULTS: The global MGQ score and generalized domain score of MGQ were strongly correlated with the degree of abnormal neuromuscular transmission, as measured by SFEMG in the deltoid muscle. Scores from ocular and bulbar domains of MGQ were not related to neurophysiological findings. Physical composite scores of SF-36 correlated significantly with the abnormal SFEMG findings in the deltoid. CONCLUSIONS: The degree of disturbed neuromuscular transmission in a proximal limb muscle correlates with a patient's subjective experience of generalized myasthenic dysfunction. SIGNIFICANCE: The observed correlation adds a new dimension to neurophysiological examinations in patients with MG.     

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 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.     

Muscle atrophy in muscle-specific tyrosine kinase (MuSK)-related myasthenia gravis

Myasthenia gravis (MG) with muscle-specific tyrosine kinase (MuSK) antibody (MuSK-MG) is often associated with prominent facial and bulbar muscle atrophy. It remains unclear whether the muscle atrophy is a consequence of long-term corticosteroid treatment, or of the disease process per se. Herein, we report a steroid-naive patient with MuSK-MG who presented with severe weakness and marked atrophy of the facial and tongue muscles.