探讨SEP、NCS、SSR、F波联合检测对糖尿病周围神经病变早期诊断的价值

目的探讨SEP、NCS、SSR、F波联合检测对糖尿病周围神经病变的早期诊断价值。方法随机选取2013-01—2015-12我院门诊收治的糖尿病患者80例,并选取80例健康人群作对照,根据是否患病分为糖尿病组(n=80)和对照组(n=80)。分别对入选患者进行联合电生理检查,包括运动NCS、腓总神经、胫后神经、尺神经、正中神经感觉检查,及上下肢SEP、SSR检查、胫后神经和正中神经F波检查。结果糖尿病组NCS检查总异常率为74.6%,其中感觉神经异常比例较运动神经明显升高,差异有统计学意义(P0.05)。糖尿病组患者电生理检查F波总异常率为57.2%,其中远端运动神经传导正常者的F波异常率相对降低为50.6%。在糖尿病组中,其SEP近端周围神经电位总异常率为70.1%,而在上肢正中神经感觉传导结果为正常范围的患者中,其锁骨上电位并不存在明显异常;在下肢胫后神经感觉传导结果为正常范围内的患者中,其臀点电位异常率为62.6%。糖尿病组SSR总异常率为80.1%,在四肢NCS正常者中,其SSR异常率高达71.8%。糖尿病组应用SEP、NCS、SSR、F波联合检测的总异常率高达90.8%,均显著高于使用单项电生理检查时的异常率,差异具有统计学意义(P0.05)。结论糖尿病周围神经病变患者,NCS检查是其诊断的一种基本手段,将其与SEP、SSR、F波进行联合检测,能显著提高糖尿病周围神经病变患者的早期检出率,值得临床推广。     

早期吉兰-巴雷综合征的神经电生理特点分析

目的 分析发病4周内吉兰-巴雷综合征(GBS)患者的F波、H反射及神经传导的改变特点,探讨F波及H反射检查在早期GBS中的诊断价值.方法 回顾性分析我院40例确诊GBS患者的神经电生理资料特点,依据病程分为2组(≤2周组及＞2周组).使用卡方检验,分别对两组患者的F波、H反射、运动神经传导速度(MCV)和感觉神经传导速度(SCV)检测的异常率进行分析.结果 病程≤2周组及＞2周组F波异常比例分别为17/20、7/18,H反射的异常比例分别为13/20、12/19,MCV异常率为28.4％(25/88)、32.9％(26/79),运动神经传导远端潜伏期异常率为40.9％(36/88)、36.7％(29/79),复合肌肉动作电位波幅异常率为35.2％(31/88)、32.9％(26/79),SCV异常率为11.2％(10/89)、25.2％(24/95).两组患者中F波、H反射异常率均较高,且两组间F波异常比例(X2 =8.657,P=0.003)及SCV异常率(x2 =6.002,P=0.014)差异具有统计学意义.结论 F波及H反射对GBS的早期诊断具有一定的诊断参考价值;神经电生理检查对GBS具有重要诊断价值.     

不同电生理检测方法对糖尿病患者胫神经损害诊断价值的比较

目的比较不同的神经电生理检测方法对糖尿病患者胫神经损害的诊断价值。方法应用EMG仪对63例确诊2型糖尿病患者进行单侧胫神经运动传导速度(MCV)及感觉传导速度(SCV)、F波及H反射检测,比较四者的诊断阳性率。结果本组63例糖尿病患者胫神经四种检查方法阳性率从高到低依次为H反射(76.19%)、F波(53.97%)、SCV(36.51%)、MCV(17.46%)(均P0.05)。本组中43例无周围神经临床症状和体征的糖尿病患者胫神经四种检查方法阳性率从高到低依次为H反射(76.74%)、F波(55.81%)、SCV(32.56%)、MCV(13.95%)(均P0.05)。本组63例糖尿病患者中反映神经远端传导功能的神经传导速度总异常率为44.44%(28/63),而反映神经近端传导功能的H反射与F波总异常率为80.95%(51/63),二者比较差异有统计学意义(χ~2=17.952,P0.01)。结论四种不同的电生理检测方法可以较全面反映胫神经远近端的损害,糖尿病患者胫神经损害不仅仅限于远端,其近端亦容易受损。四种检测方法中H反射阳性率更高,可以更早发现胫神经的亚临床病变。     

45例正中神经腕管卡压神经电生理检测与临床分析

目的探讨正中神经腕管卡压(CTS)神经电生理检测价值。方法对临床的症状及体征符合CTS的45例患者行正中神经运动神经的传导速度与尺神经运动神经的传导速度检测;桡神经与正中神经拇指-腕感觉潜伏期时差值;正中神经与尺神经无名指-腕感觉潜伏期时差值;双侧正中神经F波的检测;拇短展肌、小指展肌的肌电图检测。结果 45例患者中63只异常,双侧病变18例,单侧病变27例,正中神经运动末端潜伏期延长或(及)传导速度减慢异常率31.5%,波幅减低异常率28.3%;正中神经拇指-腕感觉神经潜伏期延长异常率71.5%;合并波幅减低者异常率占79.3%;正中神经环指-腕感觉神经传导潜伏期延长异常率81.6%,合并波幅减低异常率89.4%;正中神经F波异常率33.6%;拇短展肌呈神经源性改变异常率20.1%。结论神经电生理的常规检测联合运用感觉神经潜伏期时差值法对CTS有更敏感、更精确的诊断价值。     

接触性热痛诱发电位对糖尿病小纤维神经病变的评价作用

目的 借助接触性热痛诱发电位(CHEP)为糖尿病神经病变的小纤维神经损害寻求一种新的无创客观定量方法.方法 选取糖尿病患者46例和健康人40名,应用CHEP刺激器,控制温度52℃,分别刺激所有受试者右侧前臂、手背、小腿皮肤,采用Keypoint.net肌电图仪于cz点分别记录N波潜伏期及N-P波波幅;同时行右侧上下肢感觉传导测定.结果 健康对照组各个刺激部位CHEP的引出率为100%,而糖尿病组46例中前臂7例、手背9例、小腿16例未引出肯定CHEP波形.糖尿病组较对照组N波潜伏期延长,N-P波波幅减低.糖尿病组中25例上肢感觉传导正常,其前臂刺激Cz记录的N-P波波幅较对照组减低[分别为(34.0±12.6)、(48.4 ±17.5)μV,Z=-3.151,P<0.01],N波潜伏期差异无统计学意义;手背刺激CHEP潜伏期较对照组延长[分别为(420.4±27.8)、(407.2±24.6)ms,t=2.015,P=0.048],波幅减低[分别为(28.2±10.1)、(43.0±16.6)μV,Z=-3.712,P<0.01].18例下肢感觉传导正常,其小腿刺激CHEP潜伏期延长[分别为(473.5±46.6)、(448.6±35.0)ms,t=2.219,P=0.031],波幅减低[(23.8±7.4)、(41.5±18.5)μV,Z=-3.855,P<0.01].结论 糖尿病患者在早期即有小纤维神经选择性受累,CHEP能够为其提供新的客观定量方法,具有潜在的临床应用价值.     

13例神经肌炎的临床及肌电图研究

目的:探讨神经肌炎的临床特点以及肌电图(EMG)、神经传导速度(NCV)的诊断价值。方法:分析13例神经肌炎临床表现、EMG、NCV结果。结果:13例患者均以肌肉受累为主要临床表现;11例并发有神经病变的症状及体征。13例患者NCV均有异常。所检测的104根神经NCV异常率为57.7%。F波异常率为26.9%。11例针极EMG呈神经源性与肌源性混合损害,2例呈神经源性损害。结论:EMG、NCV是有价值的电生理诊断方法。确诊神经肌炎需结合临床表现和EMG结果。     

糖尿病周围神经病的神经传导速度测定

目的 观察糖尿病患者的神经传导速度在诊断周围神经病变的应用价值.方法 对我院2009-01-2011-12收治的658例糖尿病患者进行神经传导速度测定常规糖尿病周围神经病变的筛查,分析各神经传导功能以及感觉传导速度和运动传导速度、潜伏期、波幅、波宽、波形等.结果 有四肢远端麻木、刺痛等症状者周围神经病变的阳性率较高,糖尿病病程5 a以上者阳性率也较高.胫后神经病变在四肢神经病变中最常见,其次为腓总神经.传导速度的波幅下降最为灵敏,波形和波宽的变化也较为明显.结论 检测糖尿病患者的神经传导速度可用于周围神经病变的诊断,神经传导速度的变化对周围神经病变具有重要意义.     

血脂、超敏C反应蛋白与2型糖尿病周围神经病变神经神经传导速度、F波的关系研究

目的 探讨血脂、超敏C反应蛋白与2型糖尿病周围神经病变神经电生理相关指标的关系。方法 将134例2型糖尿病患者按照是否出现周围神经病变分为糖尿病周围神经病变组(DPN组)和非糖尿病周围神经病变组(NDPN组),检测血脂相关指标、hs-CRP水平与DPN中神经传导速度、F波的出现率。结果 DPN组的病程、TG、LDL-C、MAU、HbA1c及hs-CRP水平显著高于NDPN组(P<0.05),而FINS和HOMA-IRI显著低于NDPN组(P<0.05); DPN组正中神经、尺神经、胫后神经、腓肠神经及腓总神经的NCV均显著低于NDPN组(P<0.05); DPN组正中神经、胫后神经F波的出现率、传导速度均显著高于NDPN组(P<0.05); Logistic回归分析显示,病程、TG、MAU、LDL-C水平、F波及hs-CRP水平为DPN的危险因素,NCV、FINS、HOMA-IRI为其保护因素。Spearman相关性分析显示,TG水平与hs-CRP、LDL-C水平、F波呈正相关(r分别为0.501, 0.451,0.488,P均<0.05),与HOMA-IRI、NCV呈负相关(r分别为-0.461,-0.503,P均<0.05); LDL-C水平与MAU、hs-CRP水平及F波呈正相关(r分别为0.492, 0.487,0.511,P均<0.05),与FINS、HOMA-IRI及NCV呈负相关(r分别为-0.472,-0.469,-0.527,P均<0.05); hs-CRP水平与MAU、LDL-C、TC水平、TG及F波呈正相关(r分别为0.421,0.387,0.445,0.498,0.504,P均<0.05),与FINS、HOMA-IRI、NCV呈负相关(r分别为-0.482,-0.492,-0.521,P均<0.05)。结论 TG、LDL-C、hs-CRP水平与DPN神经传导速度异常、出现F波及F波传导速度增高有显著关系。     

糖尿病周围神经病运动神经传导速度分布

目的分析早期糖尿病周围神经病运动神经传导速度分布特点。方法对60例早期糖尿病周围神经病患者进行临床观察及神经系统查体,常规测定运动及感觉神经传导速度,运用计算机辅助对冲方法测定运动神经传导速度分布范围,并与10名健康志愿者的检测结果进行比照。结果正中神经最慢速度(CV10%)为(46.7±5.7)m/s、中等速度(CV50%)为(50.6±5.2)m/s、最快速度(CV90%)为(53.4±5.0)m/s;尺神经CV10%为(47.4±5.6)m/s、CV50%为(51.6±5.3)m/s、CV90%为(55.0±5.4)m/s;腓总神经CV10%为(34.9±5.4)m/s、CV50%为(39.2±4.6)m/s、CV90%为(42.7±4.7)m/s。除正中神经和尺神经的CV10%及所有检测神经的CV50%外,60例患者与健康人的结果均数比较差异有统计学意义。结论运动神经速度分布峰值左移,各级速度纤维传导均减慢。各级纤维非均匀损害,快传导速度纤维优先受累最常见。运动神经速度分布检测比常规运动传导测定更敏感、稳定,可用于糖尿病周围神经病早期诊断和发现亚临床病变。     

神经肌电图在合并周围神经病变的Ⅱ型糖尿病患者中的意义

目的主要探讨的是神经肌电图在Ⅱ型糖尿病患者周围神经病变的早期诊断中的价值。方法分析2011年7月至2014年1月在我院治疗的Ⅱ型糖尿病患者的临床资料。入组的Ⅱ型糖尿病患者根据患者的病程进行分组,包括A组（病程〉10年）、B组（病程1-10年）和C组（病程〈1年）。比较三组患者的临床资料,正中、尺神经、腓总神经的MCV（运动传导速度）,SCV（感觉传导速度）以及胫神经H反射和尺神经f波的情况。结果本研究共纳入研究对象180例,其中A组57例,B组65例,C组58例。三组患者的正中神经（χ2=9.104,P=0.011）、尺神经（χ2=9.335,P=0.009）、腓总神经（χ2=9.898,P=0.007）的MCV异常比例均存在着显著的差异,且病程越长,异常率越高;三组患者的正中神经（χ2=13.44,P=0.001）、尺神经（χ2=13.56,P=0.001）、腓总神经（χ2=24.09,P=0.000）的SCV异常比例均存在着显著的差异,病程越长,异常率越高;三组患者胫神经H反射异常比例存在显著的差异（χ2=19.12,P=0.000）,且病程越长,异常率越高。而尺神经F波异常比例并无统计学差异（χ2=3.152,P=0.207）。结论Ⅱ型糖尿病患者的病程越长,相应的尺神经、正中神经、腓总神经的MCV、SCV中的异常比例,以及胫神经的H反射异常检出率越高。结合尺神经F波可早期客观检测到糖尿病周围神经病神经近端损害,提高早期诊断。     

Brucella: a cause of peripheral neuropathy

Brucellosis is a common infectious disease in Mediterranean countries. We evaluated the peripheral nerve involvement in patients with brucellosis. Thirty-eight patients with brucellosis were examined. Four of them were excluded because of B(12) deficiency and diabetes mellitus. Thirty-four patients were included. The average age was 43.08 +/- 15.3 years. Patients were divided into two groups according to the abnormality in their peripheral nervous system (PNS) examination. All patients underwent nerve conduction and needle electromyography EMG studies. Twenty normal healthy subjects were used as a control group. Axonal sensorimotor neuropathy was determined in 12 patients who also had abnormality in PNS examination. After 6 months of treatment, nerve conduction studies were nearly normal in these patients. The EMG findings of the remaining 22 patients were normal, as well as the clinical examination. However, the motor conduction velocities of median (p < 0.001), peroneal (p < 0.001), and ulnar (p < 0.05) nerves were decreased, F wave latencies were prolonged in the posterior tibial and peroneal nerve, and distal latency was also prolonged in the posterior tibial nerve (p < 0.05) when compared to healthy subjects. Sensory conduction velocities of the median (p < 0.001), ulnar and sural (p < 0.05) nerve were also decreased. Brucellosis may be considered as a cause of clinical or subclinical peripheral neuropathy and should be evaluated especially in endemic areas.     

F wave duration in mild S1 radiculopathy: comparison between the affected and unaffected sides.

OBJECTIVES: The aim of this study was to investigate the F wave duration (Fdur) of the tibial nerve in mild S1 radiculopathy. We evaluated the difference in this parameter between the affected and unaffected sides, and discussed the clinical significance of this difference. METHODS: Bilateral tibial F waves were obtained from 46 normal subjects (control group) and 27 patients with L5/S1 intervertebral disc herniation (patient group). Minimum latency of F wave (Fmin) and Fdur were analyzed. RESULTS: Fmin and Fmin corrected by the subject's height (Fmin/H) were both significantly longer on the affected side than on the unaffected side and in the normal group, but the incidence of abnormality was very low for both parameters. Even patient showing normal Fmin or Fmin/H sometimes exhibited Fdur values prolonged beyond the reference range. Judgment of abnormal Fdur based on the difference between the two sides was the most sensitive method for detecting the root injury. No patients showed decreased Fdur. There was no significant difference between the two groups in the amplitude of compound muscle action potential of the abductor hallucis. CONCLUSIONS: Our study suggested that evaluation of the difference in Fdur between the two sides was a valuable means of decreasing false-negative results in F wave study in mild S1 radiculopathy cases.     

F response and somatosensory and brainstem auditory evoked potential studies in HMSN type I and II.

To evaluate conduction along the proximal and distal segments of motor and sensory long limb nerves, as well as along the very short acoustic nerve, F response and somatosensory and brainstem auditory evoked potential were studied in a series of patients with hereditary motor and sensory neuropathy (HMSN) types I and II. A diffuse and comparable slowing of conduction in proximal and distal nerve segments, as well as along the acoustic nerve, seems to favour a primary myelin defect in HMSN I. F response and motor conduction velocity showed a similar derangement in both proximal and distal motor segments. Latencies of somatosensory evoked potentials were symmetrically prolonged and correlated with motor nerve impairment. Central conduction times were normal. Studies of brainstem auditory evoked potentials showed a high incidence of acoustic nerve involvement, the most evident abnormality being a statistically significant increase in the latency of the I wave. Our data seem to support the presence of primary myelinopathic damage in HMSN I.     

Proximal nerve conduction by high-voltage electrical stimulation in S1 radiculopathies and acquired demyelinating neuropathies.

OBJECTIVE: To evaluate the reliability and sensitivity of the high-voltage electrical stimulation for studying proximal conduction of peripheral motor axons in normal subjects, S(1) radiculopathies and acquired demyelinating neuropathies. METHODS: Twelve patients with compressive S(1) radiculopathy, 22 patients with acquired demyelinating neuropathy and 29 healthy volunteers were examined. The conduction of peripheral motor axons between lumbosacral roots and the sciatic nerve at the gluteal fold was investigated by high-voltage electrical stimulation delivered percutaneously. RESULTS: The main electrophysiological finding in S(1) radiculopathy was an abnormal side to side difference in the amplitude of the compound motor action potential by proximal stimulation. Overall, the frequency of abnormalities detected by using high-voltage electrical stimulation was similar to that found with conventional EMG studies, and the two methods showed electrophysiological alterations in the same patients. In all patients with acquired demyelinating neuropathy, the proximal motor nerve conduction velocity from lumbosacral roots to the sciatic nerve at the gluteal fold was reduced; proximal stimulation of the motor axons revealed electrophysiological abnormalities more often than when using other electrophysiological techniques (F wave and H reflex). CONCLUSIONS: High-voltage electrical stimulation of peripheral motor axons shows high sensitivity in detecting proximal neuropathies; it can also define the site and relevance of proximal lesions in the peripheral nervous system better than other conventional techniques.     

一氧化二氮滥用致周围神经病患者的神经电生理特点

目的探讨一氧化二氮(N_2O)滥用致中毒性周围神经病患者的神经电生理特点。方法回顾性分析10例N_2O滥用导致的周围神经病患者的神经电生理(神经传导速度测定、针极肌电图检查、F波、H波)特点。结果与正常参考值相比,上、下肢近端所检运动纤维及上、下肢远端所检运动纤维异常率分别为0、40%、37.5%、90%,异常运动纤维远端潜伏期(MLAT)分别延长0、36.1%、17.8%、37.2%,复合肌肉动作电位(CMAP)分别下降0、88.6%、31.4%、64.5%;上、下肢远端运动纤维运动传导速度测定(MCV)分别延长10.4%、16.4%;上、下肢远端感觉纤维异常率分别为7.5%、80%;上、下肢异常感觉纤维波幅分别下降7.5%、79.4%,感觉传导速度测定分别延长0、8.6%;上、下肢F波异常率分别为0、50%;双下肢H波异常率100%;双上肢针极肌电图异常率30%,双下肢针极肌电图异常率90%(P<0.05)。结论N2O滥用致周围神经损害可同时累及运动纤维与感觉纤维,以轴索损害为主,下肢受累为著,远端受累较近端受累为重,具有长度依赖性及对称性。针极肌电图可早期出现中-多量失神经电位,大力收缩募集减少,伴或不伴运动单位时限增宽。神经电图提示F波出现率减少或H波波幅降低,伴或不伴潜伏期延长。     

Sensory nerve conduction in the upper limbs at various stages of diabetic neuropathy

In 59 diabetic patients, sensory nerve potentials were recorded at various sites along the course of the median nerve. Pathological responses were characterized by reduced amplitude, desynchronization and decreased conduction velocity (CV). Four groups of patients with increasingly severe nerve dysfunction were distinguished. The presence and severity of clinical neuropathy in the upper limbs could be related to decreased maximal sensory nerve CV in the proximal segment of the limbs. When maximal sensory nerve CV was normal above the wrist, neuropathy usually remained latent. In severe cases where no sensory nerve potentials could be recorded, the cerebral evoked potentials nonetheless permitted a precise evaluation of the somatosensory conduction. In these cases, maximal sensory nerve CV was very low. In five patients with a so-called diabetic mononeuropathy, abnormal nerve potentials were recorded in the median nerve, although no clinical signs could be seen in the corresponding territory. It is proposed that the diabetic nature of a mononeuropathy can be assessed by the finding of latent abnormalities in seemingly normal nerve.     

正常人正中神经、尺神经运动传导速度及F反应的检测研究

目的 研究正常人不同年龄、性别运动神经传导速度（MCV）和F反应的正常值,为临床诊断提供合理的数据。方法 健康志愿者155人,18－82岁,男76人,女79人。分别检测双侧正中神经、尺神经MCV和腕点刺激F反应。分析指标包括远端潜伏期、近端潜伏期、MCV、F波潜伏期、F－M波间期、F波传导速度（FCV）和F波比值等。结果 不同年龄、性别间M波潜伏期、MCV、F波潜伏期、F－M波间期、FCV均有显著差异。女性的各潜伏期较男性为短,传导速度则快于男性,不同年龄、性别、不同神经间及同名神经左、右侧间F波比值无显著差异。MCV近端快于远端。结论 MCV和F反应各参数随年龄增长出现进行性变化,性别也有差别,故不同年龄组和性别应沿用各自的正常值。F波比值可作为粗略计近远端传导功能状态的手段之一。     

Generator sites for spontaneous activity in neuromyotonia. An EMG study

A 16-year-old female patient with symptoms and signs compatible with neuromyotonia was studied with various neurophysiological tests and with muscle biopsy. Nerve conduction studies revealed signs of axonal motor neuropathy. EMG showed denervation in distal muscles, and moderate neurogenic changes in other muscles. Abundant spontaneous motor unit activity was recorded in all muscles. This activity did not disappear upon proximal nerve blockade with local anaesthetics. Based on the shape of spontaneous discharges and their behaviour on nerve stimulation and during voluntary effort, the site of generation was suggested. This varied for different discharges, from proximally in the nerve, to various sites along the intramuscular nerve tree. In some axons there were signs of conduction block proximal to the generation site for the spontaneous discharges. Different axons showed various degrees of abnormality; local hyperexcitability triggering new impulses only after the passage of a preceding impulse, increased hyperexcitability generating spontaneous activity, total impulse blocking, and finally axonal degeneration.Treatment with dihydantoin reduced the spontaneous activity with concomitant clinical improvement.     

Isolated absence of F waves and proximal axonal dysfunction in Guillain-Barré syndrome with antiganglioside antibodies

OBJECTIVES: To investigate the pathophysiology of selective absence of F waves and its relation with antiganglioside antibodies in Guillain-Barré syndrome (GBS). Some patients with GBS show the absence of F waves as an isolated conduction abnormality, which has been interpreted as demyelination in the proximal nerve segments. METHODS: In 62 consecutive patients with GBS, sequential nerve conduction and F wave studies were reviewed, and antibodies against ganglioside GM1, GM1b, GD1a, GalNAc-GD1a, GD1b, and GQ1b were measured by an enzyme linked immunosorbent assay. RESULTS: In the first electrophysiological studies, isolated absence of F waves was found in 12 (19%) patients. Sequential studies in 10 of these patients showed two electrophysiological sequel patterns; rapid restoration of F waves (six patients), and persistent absence of F waves with distal motor nerve degeneration (acute motor axonal neuropathy, four patients). None of the 10 patients showed evidence of demyelination in the proximal, intermediate, or distal nerve segments throughout the course. Of the 62 patients, IgG antibodies against GM1, GM1b, GalNAc-GD1a, or GD1b were significantly associated with the electrodiagnosis of acute motor axonal neuropathy, and patients with these antibodies more often had isolated absence of F waves than patients without them (11 of 36 (31%) v one of 26 (4%); p<0.01). Eleven of the 12 patients with isolated absence of F waves had positive serology for one or more antiganglioside antibodies. CONCLUSIONS: In GBS with antiganglioside antibodies, isolated absence of F waves is a frequent conduction abnormality especially in the early phase of the disease, and may be caused by axonal dysfunction, such as physiological conduction block or axonal degeneration at the nerve roots.     

EMG and nerve conduction studies in children with congenital muscular dystrophy

Motor and sensory nerve conduction velocities (NCVs) and needle electromyography (EMG) results were reviewed in 26 children with different types of congenital muscular dystrophy (CMD), including patients with mutations in the genes LAMA2, FKRP, and COL6A2. In every patient, at least one EMG examination detected myopathic changes that were predominant in proximal muscles, although EMG performed at birth was normal in two patients. Brief bursts of high-frequency repetitive discharges were electrically elicited in four patients. Uniformly slowed motor NCVs without signs of denervation were observed in seven patients: five merosin-deficient, one merosin-positive, and one with unavailable merosin status. The merosin-deficient neuropathy also involved sensory nerves in three patients and worsened with age in two. In conclusion, myopathic EMG changes were typical and early findings in all types of CMD. An associated neuropathy was detected in most patients with merosin-deficient CMD, and also in a child with normal merosin expression.