单纤维肌电图对糖尿病周围神经病及糖尿病肾病的早期诊断价值

目的探讨单纤维肌电图(SFEMG)对糖尿病周围神经病(DPN)及糖尿病肾病的早期诊断价值。方法应用SFEMG对43例2型糖尿病患者行指总伸肌的颤抖(jitter)和纤维密度(FD)测定,同时检测神经传导速度(NCV),并测空腹血糖(FBG)、糖化血红蛋白(HbA1c)、血脂、同型半胱氨酸(Hcy)及尿微量白蛋白/尿肌酐比值(UACR)。比较SFEMG和NCV的异常检出率,并分析颤抖和FD与病程、LDL-C、HbA1c、Hcy、UACR的相关性。结果全部患者颤抖、FD和NCV的异常检出率分别为65.1%、53.5%和48.8%,24例无DPN症状患者分别检出9例(20.9%)、4例(9.3%)和2例(4.7%)。颤抖和FD呈正相关,且均与病程、LDL-C、HbA1c、Hcy和UACR呈正相关。结论 SFEMG是DPN的早期诊断指标,SFEMG异常者行HbA1c、Hcy和UACR联合检测对DPN和糖尿病肾病的早期诊治有帮助。     

单纤维肌电图对糖尿病周围神经病的诊断价值

目的 探讨单纤维肌电图（SFEMG）在糖尿病周围神经病（DPN）中的应用。方法 采用Viking Ⅳ肌电图仪,测定36例2型糖尿病患者指总伸肌的颤抖和纤维密度（FD）,同时进行常规神经传导检测（NCS）并测量空腹血糖和糖化血红蛋白（HbA1C)。结果 颤抖和FD具有相关性,且均与HbA1C呈正相关。18例NCS异常者,颤抖值均超过正常范围（11例伴阻滞）,14例FD增加;18例NCS正常者,7例颤抖值增大（3例伴阻滞）,5例FD增加。结论 颤抖和FD所反映的失神经－神经再支配与代谢状况相关联;SFEMG是DPN早期诊断的敏感手段,可发现糖尿病亚临床周围神经病变。     

RNS与SFEMG在检测ALS患者神经肌肉接头功能紊乱的比较研究

目的探讨重复神经电刺激(RNS)与单纤维肌电图(SFEMG)在检测肌萎缩侧索硬化(ALS)患者神经肌肉接头功能紊乱中的吻合率及RNS低频递减阳性率与SFEMG指标纤维密度(FD)、颤抖(jitter)、阻滞(block)的关系。方法收集2008-5—2009-4在北京协和医院神经科门诊或病房确诊或拟诊的ALS患者43例,同时行RNS及SFEMG检查。比较RNS与SFEMG在判断ALS患者神经肌肉接头紊乱的敏感性和特异性,并分析RNS低频递减与SFEMG参数指标jitter、block、FD的相关性。结果(1)43例患者中26例RNS(+),占60.5%,17例RNS(-),占39.5%。SFEMG(+)34例,占79.1%,SFEMG(-)9例,占20.9%。其中SFEMG(+)+RNS(+)者共25例,SFEMG(-)+RNS(-)者8例。RNS在判断ALS存在神经肌肉接头受累方面与SFEMG比较有一定的吻合性(Kappa=0.47,P0.01)。(2)RNS阴性和阳性组FD间比较无统计学差异(t=-0.1405,P0.05)。RNS阳性组Block程度明显高于RNS阴性组(χ~2=11.432,P0.01),jitter值也明显高于RNS阴性组(t=2.906,P0.01)。桡神经RNS波幅递减程度与jitter值呈正相关(r=0.626,P0.05)。结论 RNS与SFEMG比较有一定的吻合率。RNS检查灵敏度较高,具有操作简单,费用低,耗时短,无创,不需患者特殊配合,近远端肌肉均可操作,易于推广的特点,对ALS患者的辅助诊断具有意义。     

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。     

单纤维肌电图在68例运动神经元病患者中的研究

目的　研究运动神经元病 (MND)患者的单纤维肌电图 (SFEMG)改变、病理生理机制及临床意义。方法　对 6 8例 (男 4 3例 ,女 2 5例 )经病史、临床表现和神经电生理检查测定证实的MND患者进行了伸指总肌SFEMG测定 ,并与年龄匹配的正常人对照。结果　所有患者感觉神经传导速度测定均正常 ,肌电图为广泛神经源性损害。SFEMG检查发现 :颤抖值 (jitter)为 30～ 178μs,平均 (80 2± 32 6 ) μs ;jitter>5 5 μs占 5 0 %～ 10 0 0 % ,平均 6 0 6 %± 2 9 0 % ;阻滞 (block)所占百分比为 0 0 %～90 0 % ,平均 2 9 3%± 30 0 % ;纤维密度 (FD)为 1 4～ 4 0 ,平均 2 6± 0 6。其中 5 1例确诊和拟诊的肌萎缩侧索硬化患者jitter增宽、block和FD增高最明显。还发现伸指总肌肌无力的程度与jitter增宽和block百分比呈明显的负相关。结论　SFEMG的异常改变在确诊患者组最明显 ;jitter增宽、block百分比升高和FD增高与肌肉无力的严重程度呈明显的负相关 (P <0 0 0 1) ;jitter增宽、block百分比升高和FD增高反映进行性失神经、神经再生和神经肌肉接头处的传递情况     

单纤维肌电图在甲亢伴眼肌型重症肌无力和Graves眼病鉴别诊断中的价值

目的探讨单纤维EMG(SFEMG)技术在甲亢伴眼肌型重症肌无力(OMG)与Graves眼病鉴别诊断中的价值。方法对32例甲亢伴OMG、35例Graves眼病患者进行眼轮匝肌SFEMG测定,分析两组间SFEMG改变的特点。结果在2组患者中,平均颤抖(jitter)值分别为(96. 2±23. 7)、(42. 8±12. 6)μs,jitter 55μs的百分比M50分别为92%、5%,阻滞所占百分比M50分别为25%、0,纤维密度分别为(1. 9±0. 4)、(1. 7±0. 5)。两组比较,甲亢伴OMG患者各SFEMG参数均明显高于Graves眼病患者组(分别t=15. 56,Z=9. 26,Z=7. 35,均P 0. 01)。结论甲亢伴OMG患者的眼轮匝肌SFEMG均表现为jitter明显增宽,可伴有阻滞,与Graves眼病患者明显不同。眼轮匝肌SFEMG测定有助于甲亢伴OMG和Graves眼病的鉴别诊断。     

单纤维肌电图在肌萎缩侧索硬化鉴别诊断中的价值

目的 探讨单纤维肌电图(SFEMG)技术在肌萎缩侧索硬化(ALS)鉴别诊断中的价值.方法 对我院收治的165例ALS患者和145例下运动神经元受累为主的非ALS疾病患者进行伸指总肌SFEMG测定,并测定伸指总肌肌力,按照伸指总肌肌力进行分组,分析不同组之间SFEMG改变的特点.结果 伸指总肌肌力正常者,ALS和非ALS组的平均颤抖(jitter)值分别为(66.1±20.1)、(38.0±9.2)μs(t=9.05),jitter＞55μs的百分比中位数分别为55%、0(Z=-7.81),阻滞所占百分比中位数分别为6.7%、0(Z=-6.93),ALS组各参数均明显高于非ALS组(均P＜0.01).伸指总肌肌力医学研究委员会(MRC)评分≤4者,ALS和非ALS组平均jitter值分别为(93.5±31.2)、(52.8±25.9)μs(t=9.37),jitter＞55μs的百分比中位数分别为86%、20%(Z=-8.46),阻滞所占百分比中位数分别为20%、0(Z=-7.25),ALS组各参数均明显高于非ALS组(均P＜0.01).在MRC评分＞4者,采用平均jitter＞55μ s诊断ALS的敏感性和特异性分别为70.2%和92.7%.结论 当采用SFEMG测定协助ALS的诊断和鉴别时,应尽量选择肌力正常的肌肉.平均jitter、jitter＞55μs的百分比和阻滞在ALS与其他下运动神经元疾病的鉴别诊断中具有重要价值.     

肌电图在糖尿病周围神经病变诊断中的临床应用

目的分析神经肌电图(EMG)在2型糖尿病(T2DM)合并糖尿病周围神经病变(DPN)诊断中的应用价值。方法选取200例T2DM合并DPN患者为研究对象,根据患者的T2DM病程长短分为A组、B组、C组和D组,应用EMG对四级患者的上肢正中神经、尺神经的运动传导速度(MCV)和感觉传导速度(SCV)、下肢的腓总神经MCV、腓浅神经SCV、胫神经H反射和尺神经f波进行检测和比较。结果 A组的EMG异常检出率显著高于其他3组(χ2=4.604、9.558、17.420,P0.05),B组显著高于D组(χ2=5.034,P0.05);A组患者的腓总神经MCV异常检出率显著高于C组或D组(χ2=5.514、9.007,P0.05);A组患者的腓浅神经SCV异常检出率显著高于其他3组(χ2=6.000、6.484、19.841,P0.05),B组、C组均显著高于D组(χ2=4.602、4.905,P0.05);A组的胫神经H反射异常检出率显著高于其他3组(χ2=7.332、17.160、24.008,P0.05),B组显著高于D组(χ2=5.784,P0.05)。结论随着T2DM病程的进展,DPN患者的EMG异常率会出现显著上升,主要表现为腓总神经MCV、腓浅神经SCV和胫神经H反射异常率的显著升高,临床医生应综合考虑患者的EMG变化情况以针对DPN进行早期诊断和及时治疗。     

单纤维肌电图在肌萎缩侧索硬化和颈椎病鉴别诊断中的价值

目的 探讨单纤维肌电图(SFEMG)技术在肌萎缩侧索硬化(ALS)与神经根型和脊髓型颈椎病鉴别诊断中的价值.方法 对61例ALS伴有MRI颈椎病表现、59例ALS不伴MRI颈椎病表现、55例神经根型和脊髓型颈椎病患者进行伸指总肌SFEMG测定,分析不同组之间SFEMG改变的特点.结果 在3组患者中,平均颤抖(jitter)值分别为(81.2±25.9)、(91.6±32.4)、(40.9±11.8) μs,jitter>55 μs的百分比M50分别为73%、80%、5%,阻滞所占百分比M50分别为10%、20%、0,纤维密度分别为2.9±0.5、2.9±0.6、2.4±0.6.ALS伴和不伴MRI颈椎病变2组之间各参数比较差异无统计学意义.两组ALS患者合并后[平均jitter值(86.3±29.6)μs,jitter>55μs的百分比M50为80%,阻滞所占百分比M50为14%,纤维密度2.9±0.5]再与颈椎病组比较,各参数均明显高于颈椎病组(分别为t=14.49,Z=8.96、7.68,t=5.83,均P=0.000).在经随诊而确诊的18例ALS患者中,初诊时肌电图仅有1个节段的神经源性损害,在伸指总肌肌力和常规肌电图均正常情况下,有16例SFEMG可见纤维密度增高,13例jitter增宽,6例可见阻滞.结论 ALS伴或不伴MRI颈椎病变的SFEMG均表现为jitter明显增宽,可伴有阻滞,纤维密度增高,与神经根型和(或)脊髓型颈椎病患者明显不同.SFEMG测定有助于ALS与颈椎病的鉴别诊断.     

早期糖尿病周围神经病患者的EMG改变及其与血清脂蛋白相关磷脂酶A2水平的关系

目的探讨早期糖尿病周围神经病(DPN)患者的EMG改变及其与血清脂蛋白相关磷脂酶A2(Lp-PLA2)水平的关系。方法对90例早期DPN患者行EMG检查,测定内容包括双侧神经运动传导速度(MCV)、复合肌肉动作电位波幅(CMAP)、感觉传导速度(SCV)、感觉神经动作电位波幅(SNAP)及胫神经H波和尺神经f波,分析其与患者血清Lp-PLA2水平的关系。结果 90例早期DPN患者EMG检查总异常率为90.0%。早期DPN患者下肢运动神经异常率(68.6%)显著高于上肢异常率(24.5%)(χ~2=123.863,P=0.000)。早期DPN患者下肢感觉神经异常率(87.4%)显著高于上肢异常率(54.7%)(χ~2=82.712,P=0.000)。早期DPN患者感觉神经总异常率(71.1%)显著高于运动神经总异常率(46.5%)(χ~2=78.978,P=0.000)。DPN患者胫神经H反射总异常65例(72.2%),尺神经f波总异常14例(15.6%)。根据血清LpPLA2水平,90例早期DPN患者分为低水平组(36例)、中水平组(25例)和高水平组(29例)。与低水平组比较,中水平组及高水平组MCV、SCV异常率及CMAP、SNAP下降率均明显降低,且高水平组MCV、SCV异常率及CMAP、SNAP下降率均明显低于中水平组(均P0.05)。Spearman秩相关分析结果显示,血清Lp-PLA2水平与MCV、SCV异常率及CMAP、SNAP下降率均呈负相关(r=-0.741,r=-0.773,r=-0.652,r=-0.611;均P0.05)。结论 EMG检查对DPN早期诊断有重要价值,维持血清Lp-PLA2水平稳定对早期DPN的治疗可能有重要意义。     

2型糖尿病并发糖尿病周围神经病变与代谢综合征的关系

目的 探讨2型糖尿病(T2DM)并发糖尿病周围神经病变(DPN)与代谢综合征(MS)的关系。方法 选取我院收治的T2DM患者95例,按是否并发MS进行分组,并发MS 45例为研究组,无MS为对照组50例。2组均进行电生理检查、MS相关指标的血液、尿液标本测定,统计2组DPN发生率,比较2组SCV和MCV及MS相关指标水平,并进行影响DPN的多因素Logistic回归分析。结果 研究组DPN发生率为62.22%,对照组为12.00%,差异有统计学意义(P0.01)。2组左右腓神经SCV、MCV比较有显著差异(P0.01)。2组TC、TG、LDL-C比较差异无统计学意义(P0.05),2hINS、UA、HbA1c、CRP、UAER水平比较有明显差异(P0.01)。多因素Logistic回归分析结果显示,HbA1c、UAER、2hINS、CRP等MS相关指标异常均为DPN的危险因素。结论 T2DM并发DPN与MS密切相关,MS相关指标,如HbA1c、UAER、2hINS等水平过高是导致DPN发生的高危因素,故临床在控制血糖的时候应注重患者MS相关指标的检测与调控。     

Electrophysiological spectrum of inclusion body myositis

We present electrodiagnostic data on 30 patients with inclusion body myositis (IBM) in order to better delineate its electrophysiological features. Comprehensive electromyography (EMG) and nerve conduction studies (NCS) were performed in all cases. Twelve patients had single fiber electromyography (SFEMG). EMG showed abundant short-small motor unit potentials (MUP) with fibrillations and positive sharp waves in 56.6% of patients, and a mixed pattern of large and small MUP in 36.7%. In 6.7%, only "neurogenic" features were seen. NCS were slow in 33.3%. SFEMG revealed a mildly abnormal jitter and a slightly increased fiber density. IBM demonstrates a heterogeneous EMG profile. A pattern of large and small MUP is highly suggestive of IBM but is seen in only about one third of cases.     

Electrophysiological study of neuromuscular system involvement in mitochondrial cytopathy.

OBJECTIVES: To define the neuromuscular involvement in 'mitochondrial' patients with clinical evidence of a neuromuscular disorder, and to evaluate if the proposed electrophysiological protocol was suitable to reveal a subclinical neuropathy or myopathy in 'mitochondrial' patients with no clinical sign of a neuromuscular disturbance. METHODS: Quantitative concentric needle electromyography (CNEMG), single fiber electromyography (SFEMG) and nerve conduction studies (NCS) were performed in 33 patients with mitochondrial cytopathies. Lastly, we studied 9 clinically unaffected relatives. RESULTS: NCS were abnormal in 18% of patients, with CNEMG and SFEMG in 58% of cases, but there was not a complete overlapping of the positivity of the different techniques. No asymptomatic relatives showed abnormalities of the electrophysiological studies. CONCLUSIONS: Electrophysiological findings did not correlate with any specific biochemical or genetic defect, but were consistent with clinical diagnosis in almost all of the patients with clinical signs of myopathy and/or neuropathy. Increase of both SFEMG jitter and fiber density was significantly tied to a neuropathic process. CNEMG and SFEMG were altered in about 30% of subjects without clinical signs of myopathy or neuropathy and were therefore able to reveal a subclinical involvement of neuromuscular system in some patients who had external ophthalmoplegia or retinitis only.     

Hcy和Cys-C水平与糖尿病周围神经病变的相关性研究

目的 探讨2型糖尿病(T2DM)周围神经病变患者血浆同型半胱氨酸(Hcy)、胱抑素C(Cys-C)的水平变化及其意义。方法 选取2016年1月～2016年12月本院确诊的T2DM周围神经病变患者88例(DPN组),另选88例年龄、性别与之匹配的单纯T2DM患者(对照组),检测并比较2组的血浆Hcy、Cys-C的水平,采用非条件Logistic回归分析T2DM患者并发周围神经病变的危险因素。结果 DPN组的糖尿病病程、HbA1c测定值均高于对照组(P<0.05); DPN组的HDL-C水平低于对照组(P<0.05); DPN组的血浆Hcy、Cys-C的水平均高于对照组(P<0.05); 糖尿病患者并发周围神经病变的危险因素为糖尿病病程(OR=1.829)、HbA1c(OR=1.558)、Hcy(OR=1.629)、Cys-C(OR=1.733)(P<0.05)。结论 血浆Hcy、Cys-C高水平是糖尿病患者并发周围神经病变的独立危险因素。     

Single-fiber electromyography,nerve conduction studies,and conventional electromyography in patients with critical-illness polyneuropathy: Evidence for a lesion of terminal motor axons

Nine patients at risk for critical illness polyneuropathy (CIP) were included in a prospective study. We performed nerve conduction studies, electromyography, and a stimulation single-fiber electromyography (SFEMG). Five of 9 patients were diagnosed as CIP because they developed abnormal spontaneous activity during the follow-up period. Their SFEMG revealed a significant increase in mean jitter (25%, P < 0.005). In 4 patients without abnormal spontaneous activity there was no significant increase in the mean jitter, although 1 of the latter 4 patients showed an increased jitter, indicating that abnormal SFEMG may precede abnormal spontaneous activity. Nerve conduction studies did not show any significant changes in both patient groups. Our findings suggest that CIP is a primarily axonal motor neuropathy. The increased jitter in patients with CIP indicates that CIP is a primarily axonal neuropathy with a lesion of terminal motor axons. © 1997 John Wiley & Sons, Inc. Muscle Nerve, 20, 696–701, 1997.     

Single fibre EMG in 6 cases of botulism

ABSTRACT- In 6 cases of mild botulinum intoxication, conventional EMG and single fibre EMG (SFEMG) were performed on admission to our ward (about 15 days after ingestion of the toxin) and 4, 8 and 14 weeks after admission.
In 4 cases, conventional EMG resulted in abnormal findings; and they normalized 4 weeks later. On the first examination, SFEMG revealed in all cases but one the occurrence of potential pairs with abnormal jitter (above 50 μs). The % of the potential pairs with abnormal jitter ranged in different cases from 17% to 44%. Some of the potential pairs with abnormal jitter showed blockings; the occurrence of blockings was not strictly related to jitter value. Mean jitter value and % of potential pairs with abnormal jitter became progressively reduced with increasing time after intoxication. Nevertheless, in 4 cases slightly abnormal findings were still present after 4 months.
The data obtained in the basal condition are in agreement with those reported by others. SFEMG findings relate fairly well to conventional EMG data and clinical status. SFEMG has proved to be a very sensitive method for studying the neuromuscular transmission defect in botulism and in obtaining further information on the course of the syndrome.     

The utility of a point-of-care sural nerve conduction device for detection of diabetic polyneuropathy: A cross-sectional study

Introduction: Rapid and accessible methods for diagnosing diabetic polyneuropathy (DPN) have been developed, but not validated, in large cohorts of people with diabetes. Methods: The performance of a point-of-care device (POCD) was studied in 168 patients with type 2 diabetes, estimating the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) compared with conventional sural nerve conduction studies (NCS). Results: A POCD amplitude limit of 6 µV increased the sensitivity (96%) and NPV (98%), but decreased the specificity (71%) and PPV (54%) compared with the 4-µV limit, which had values of 78%, 92%, 89%, and 71%, respectively. POCD on both legs showed better performance than on 1 leg. POCD amplitudes and conduction velocities correlated significantly with conventional sural NCS, but POCD values were underestimated compared with NCS. Discussion: The POCD may be used as a suitable screening tool for detection of DPN. Patients with abnormal and borderline results should undergo conventional NCS. Muscle Nerve 59 :187–193, 2019     

Application of futility analysis to refine jitter recordings in myasthenia gravis

Introduction: The current practice of single‐fiber electromyography (SFEMG) requires that 20 fiber pairs with normal jitter be collected to exclude myasthenia gravis (MG). We applied principles of futility analysis from clinical trials in an attempt to reduce that requirement. Methods: We utilized conditional power futility analysis to assess the probability of an abnormal 20‐pair SFEMG based on ongoing analysis of jitter as each pair is collected. Rules for early test termination in the presence of 0, 1, or 2 abnormal pairs were identified. These rules were then applied to previously collected SFEMG data. Results: SFEMG could be stopped at just 12 pairs if all are normal and at 17 pairs if 1 is abnormal. The rules successfully determined when SFEMG could be stopped in 104 of 106 (98%) studies originally reported to be normal. Conclusions: If the first 12 SFEMG pairs have normal jitter, the study can be terminated and interpreted as normal. Muscle Nerve, 2012