运动神经元病162例的节段性运动神经传导测定分析

目的探讨运动神经元病(motor neuron d isease,MND)常规节段运动神经传导和位移技术检测的特点。方法对162例MND患者和60名健康对照进行常规节段运动神经传导测定,同时对部分神经采用位移技术测定,并进行分析比较。结果(1)健康人常规节段运动神经传导测定显示:近端与远端比较,波幅和面积下降程度均小于20%,时限增宽小于15%;(2)在MND患者,常规节段测定共有76个节段(5.57%)波幅下降超过20%,45个节段(3.30%)面积下降超过20%,76个节段(5.57%)时限延长超过15%。仅有4例(2.5%)患者4条神经的4个常规节段(0.29%)达到运动神经部分性传导阻滞标准,但采用位移技术测定时均未达到短节段传导阻滞的诊断标准。结论在大部分MND患者常规节段运动神经传导测定正常,在部分患者也可以出现“传导阻滞样”的电生理表现,但其发生率极低,进一步采用位移技术测定有助于鉴别。     

Somatosensory evoked potentials,sensory nerve potentials and sensory nerve conduction in hereditary motor and sensory neuropathy type I

Summary Thirty-nine patients from six families with hereditary motor and sensory neuropathy type I and control subjects were included in this study. A neurological deficit score (NDS) was derived from a neurological examination and compared with neurophysiological test findings. Further, sensory nerve conduction velocities (SNCV) were compared with the motor nerve conduction velocities (MNCV). Five patients whom peaks of N11/N13 complex and N20 of the median nerve sensory evoked potential (SEP) could be recorded showed normal interpeak latency. The interpeak separation P14 N20 measured in six patients was normal. These findings point to the normal function of the central conductive pathways. Erb and cervical potentials of the median nerve SEP could be recorded in 10% and 12% of the patients, respectively. In contrast, about half of the patients showed a scalp N20, while in most of them no SNCV could be measured. In six patients far-field potential P14 of the median nerve SEP was the first detectable potential. Therefore, we argue in view of the anatomical structure of the thalamus, that the first generator for synchronizing and amplification of impulses is probably located in the thalamus. A third of the patients had a cortical sural nerve SEP, while no sural nerve potentials could be recorded. No association was found between the SEP findings and the NDS. There was an inverse correlation between median SNCV and the NDS, but no relationship between the former and sensory deficit alone. In 40% of the patients median SNCV and in 13% sural SNCV could be recorded and considered to be severely decreased. In contrast, the majority of the patients had mild to moderate sensory deficit. Furthermore, patients with measurable SNCVs had higher MNCVs and lower NDS than patients without measurable SNCVs.     

Motor nerve conduction study and muscle strength in newly diagnosed poems syndrome

Introduction: Mixed demyelination and axonal loss are electrophysiological features of polyneuropathy, organomegaly, endocrinopathy, M‐protein, and skin changes (POEMS) syndrome. It is unclear whether the demyelination and axonal loss occur concurrently. Methods: Electromyography was performed in 37 patients with newly diagnosed POEMS syndrome. Compound muscle action potential (CMAP) amplitude, distal motor latency, motor conduction velocity (MCV), and spontaneous activity were collected. Muscle strength was measured according to the Medical Research Council (MRC) scale. Results: MCV decreased in all nerves with decreased CMAP amplitude and in 93% of nerves with normal amplitude. CMAP amplitude decreased in 54% of nerves with decreased MCV and was normal in all nerves with normal MCV. MCV deceased in 95% of nerves with normal MRC. Abnormal spontaneous activity was detected in 32% of upper limb muscles. Conclusions: Demyelination may be the main manifestation in POEMS neuropathy at an early stage, and axonal loss may be secondary to demyelination as the disease progresses. Muscle Nerve 51 : 19–23, 2015     

Maximal and minimal motor nerve conduction velocities determined by a collision method: correlation with axonal conduction velocity of type-identified motor units

Maximal and minimal motor nerve conduction velocities of the medial gastrocnemius (MG) muscle nerve were measured by a new collision method in 20 rats of 8–9 weeks of age; the rate of tension increase produced by the muscle was also recorded. Single motor unit analysis in the other 20 rats obtained axonal conduction velocity and contractile properties of type-identified MG motor units. Comparison of the data from these experiments revealed that the maximal and minimal motor nerve conduction velocities obtained by this collision method were most likely to be the axonal conduction velocity of fast-twitch and slow-twitch motor units, respectively. Therefore, these motor nerve conduction velocities in man may also be used as functional parameters of human fast-twitch and slow-twitch motor units, respectively.     

Supraorbital nerve conduction study in normal subjects

There is currently no examination technique that allows direct measurement of supraorbital nerve conduction velocity and amplitude. Therefore, in this study we describe a novel nerve conduction technique that allows measurement of the supraorbital sensory nerve action potential (SNAP) distal to the supraorbital foramen. Supraorbital SNAPs were recorded bilaterally from 17 healthy volunteers using an antidromic technique. The SNAPs were consistently recordable over the site 6 cm lateral to the midline point that was marked 10 cm above the nasion. Measured parameters included peak latency (mean 2.3 ms, SD 0.3), amplitude (mean 14.6 μV; SD 10.5), and velocity (mean 51.3 m/s, SD 6.8). The mean percentage of interside difference in amplitude was 25.6% (SD 17.3). Cut-off values (97th percentile) were 2.7 ms (peak latency), 3.3 μV (amplitude), 41.9 m/s (conduction velocity), and 54.9% (interside difference in amplitude). Supraorbital SNAPs can be recorded in all normal subjects and used as a quantitative measure of the functioning large fibers in the nerve.     

Muscle force,motor nerve conduction velocity and compound muscle action potentials after parathyroidectomy for secondary hyperparathyroidism

OBJECTIVE: We studied the motor nerve conduction velocity (MNCV) and the amplitude of compound muscle action potentials (CMAP) in patients with symptomatic secondary hyperparathyroidism at preoperative and 3 months post-operative period, to find the factors affecting muscle force after parathyroidectomy. METHODS: Twenty-six patients with symptomatic secondary hyperparathyroidism with levels of intact parathyroid hormone (iPTH) over 6.8 pmol/l who underwent total parathyroidectomy and autotransplantation of 60 mg of tissue were included in this research. Extension force of the quadriceps muscle was measured at 60 degrees of right knee flexion and expressed as Newtons (N) in peak force and average force. Nerve conduction studies of four limbs were checked and the MNCV and CMAP of right femoral and tibial nerves were analyzed and correlated with the muscle force. RESULTS: Three months after operation, the peak force increased from 272 +/-108 to 315 +/- 123 N (P=0.015) and the average force from 215 +/- 94 to 253 +/- 103 N (P=0.006). MNCV and latencies of femoral and tibial nerves did not show definite change, but the amplitude of CMAP increased significantly from 7.1 +/- 4.1 to 10.7 +/- 3.2 mV (P=0.005) at femoral stimulation and from 9.8 +/- 4.6 to 11.7 +/- 4.3 (P=0.007) and 13.2 +/- 5.9 to 14.9 +/- 6.0 (P=0.011) at proximal and distal tibial stimulation. CONCLUSION: The improvement of muscle force after surgery was found to be parallel to the increment of the amplitude of CMAP but not to nerve conduction velocity or latency. We propose that the weakness of the patients with secondary hyperparathyroidism is probably related to alteration of muscle fiber contraction.     

Aging influences central motor conduction less than peripheral motor conduction: A transcranial magnetic stimulation study

Introduction: In this study we investigated the effects of aging on corticospinal tract conduction by measuring the corticoconus motor conduction time (CCCT). Methods: Motor evoked potentials were recorded from the right tibialis anterior muscle in 100 healthy volunteers. To activate the most proximal part of the cauda equina, magnetic stimulation was performed using a MATS coil over the L1 spinous process (L1‐level latency). Transcranial magnetic stimulation of the motor cortex was also conducted (cortical latency). To obtain the CCCT, the L1‐level latency was subtracted from the cortical latency. Results: Age was significantly correlated with L1‐level latency, but it was not significantly correlated with CCCT. Conclusions: CCCT is the most direct indicator of corticospinal tract conduction, whereas L1‐level latency reflects whole peripheral motor conduction. Central motor conduction was found to be relatively less affected by aging compared with peripheral motor conduction. Muscle Nerve 000: 000–000, 2012     

Non-paretic lower limb muscle wasting during acute phase is associated with dependent ambulation in patients with stroke

BackgroundMuscle wasting in patients with stroke is a factor for a poor functional outcome. However, there have been few studies on the relationships between lower limb muscle wasting during the acute phase and dependent ambulation. This study examined whether lower limb muscle wasting during the acute phase is associated with the dependent ambulation status at 3 months after stroke.MethodsIn this observational cohort study, we measured the quadriceps muscle thickness in the paretic and non-paretic limbs within 1 and 3 weeks after admission using ultrasonography in non-ambulatory patients with acute stroke. Patients were categorized into two groups based on their ambulation ability: dependent, functional ambulation category (FAC) 0–3 and independent, FAC 4–5) at 3 months after stroke.ResultsIn total, 55 patients were included and completed follow-up, and 28 patients (51%) had an ambulation status of dependent at 3 months after stroke. Significant differences in muscle wasting were observed in the non-paretic limb (−5.5% [8.7%] : −16.8% [13.6%], independent group: dependent group, respectively, P < 0.001), but not in the paretic limb (−15.0% [14.3%] : −18.7% [15.1%], P = 0.36). Even after adjusting for covariates, muscle wasting in the non-paretic limb was a significant independent predictor of dependent ambulation (adjusted odds ratio, 0.87; 95% confidence interval, 0.76–0.99, P = 0.033).ConclusionPost-stroke muscle wasting in the non-paretic lower limb during the acute phase is independently associated with dependent ambulation after stroke.     

Whole plantar nerve conduction study with disposable strip electrodes

Introduction: A new method to evaluate whole plantar nerve conduction with disposable strip electrodes (DSEs) is described. Methods: Whole plantar compound nerve action potentials (CNAPs) were recorded at the ankle. DSEs were attached to the sole for simultaneous stimulation of medial and lateral plantar nerves. We also conducted medial plantar nerve conduction studies using an established method and compared the findings. Results: Whole plantar CNAPs were recorded bilaterally from 32 healthy volunteers. Mean baseline to peak amplitude for CNAPs was 26.9 ± 11.8 μV, and mean maximum conduction velocity was 65.8 ± 8.3 m/s. The mean amplitude of CNAPs obtained by our method was 58.2% higher than that of CNAPs obtained by the Saeed method (26.9 μV vs. 17.0 μV; P < 0.0001). Conclusions: The higher mean amplitude of whole plantar CNAPs obtained by our method suggests that it enables CNAPs to be obtained easily, even in elderly people. Muscle Nerve 53: 209–213, 2016     

Motor nerve impairment in diabetic patients with symmetrical distal sensory polyneuropathy: A single nerve fiber conduction velocity study

Introduction: In this study we investigated the clinical utility of single fiber conduction velocity (SF‐CV) testing in the evaluation of motor nerve function in diabetic patients with signs and symptoms of symmetrical distal sensory polyneuropathy (DSP). SF‐CV findings were compared with conventional nerve conduction studies (NCS). Methods: Twenty‐eight consecutive type 2 diabetic patients with clinically diagnosed DSP were studied. Results: SF‐CV testing of the tibial nerve was abnormal in 16 (57.1%) patients. Twelve patients with normal conventional motor NCS had abnormal findings by tibial SF‐CV. SF‐CV testing of the tibial nerve was significantly superior to all other motor NCS. Conclusions: SF‐CV testing of the tibial nerve often demonstrates motor nerve impairment in diabetic patients with sensory DSP when conventional NCS are normal. Muscle Nerve 49 : 84–89, 2014     

Experimental porta-caval anastomosis and motor nerve conduction velocity in the rat

Summary The influence of portal-systemic shunting on maximal motor nerve conduction velocity (MCV) was analyzed in rats with portacaval shunts. At 3 and 8 weeks after the shunting there was a marked but transient fall in MCV. This was not prevented by colectomy. At 16 weeks the MCV had almost normalized, despite sustained portal-systemic shunting. When examined at 3 weeks postoperatively, MCV was less affected by ischaemia than in control animals. The results favour hepatocellular failure as the more important pathophysiological mechanism in hepatic neuropathy.     

Central motor conduction in cervical dystonia with cervical spondylotic myelopathy

OBJECTIVES: It has been known that cervical dystonia develops secondarily to spinal cord injuries as secondary dystonia. However, little is known about the pathophysiological mechanism. PATIENTS AND METHODS: We examined motor and sensory conduction in six patients with symptomatic cervical dystonia by transcranial magnetic stimulation (TMS). All of the patients exhibited unilateral head rotation. They had symptoms corresponding to cervical myelopathy and felt discomfort in the neck, shoulders or arms before involuntary movement occurred. RESULTS: Although the overall central motor conduction time (CMCT) was not different from that of normal controls, contralateral CMCT was significantly delayed compared to ipsilateral CMCT (p<0.05). The results of somatosensory evoked potential study demonstrated that contralateral central conduction time (CCT) was not significantly different from ipsilateral CCT. CONCLUSION: These findings indicate that there is a selective interference with the contralateral corticospinal tract in patients with symptomatic cervical dystonia.     

Central motor conduction to upper and lower limbs after magnetic stimulation of the brain and peripheral nerve abnormalities in 20 patients with Friedreich''s ataxia

Central motor conduction time (CMCT) to thenar and soleus muscles was measured after magnetic stimulation of the cortex in 20 cases of Friedreich's ataxia (FA) and was abnormal in all. CMCT values were related to disease duration and disability. The amplitude of CMAP after cortex stimulation was severely reduced in the most disabled patients. Reduction in amplitude of the nerve evoked potentials was related neither to disease duration nor grade of disability. These results suggest that clinical worsening in FA is mainly due to progressive central motor pathway involvement. CMCT study is a better index of disease progression than peripheral nerve examination. Abnormalities in CMCT may be the third electrophysiological diagnostic criterion in FA, after reduced amplitude of nerve action potentials and absent H reflex.     

健康成人感觉神经传导相关影响因素及正常值范围研究

目的 研究影响健康成人感觉神经传导的相关因素,并建立正常值范围.方法 对213例正常成人的正中神经腕-示指、尺神经腕-小指和腓肠神经的感觉神经传导进行测定,分析其感觉传导各参数,结果 按照不同年龄、性别、身高和体质量,分别进行统计学分析.结果 体质量、身高对感觉神经传导各参数影响不大;年龄是最主要的影响因素,主要影响正中神经感觉传导各参数、尺神经和腓肠神经感觉传导波幅,而这种影响在40岁前后最明显;性别仅对某些感觉神经传导参数有影响.结论 年龄和性别是影响感觉神经传导的主要因素,正常参考值的建立应参考年龄和性别.     

Conduction velocity in motor,cutaneous afferent,and muscle afferent fibers within the same mixed nerve

Mammalian axons subserving different functions have different conduction velocities (CV); motor fibers conduct more slowly than cutaneous fibers, which conduct slower than muscle afferents. However, human studies have yielded conflicting results. We studied isolated fiber populations in human sciatic nerve to examine further this question. Motor studies were performed in standard fashion, stimulating at gluteal fold (GF) and popliteal fossa (PF) and recording soleus. In addition, conduction velocity of a pure motor nerve volley was calculated for 3 subjects. Stimulating and recording electrodes were needles placed close to the nerve. Cutaneous afferents were studied by stimulating the sural nerve at the ankle and recording at PF and GF. Muscle afferent velocity was assessed by comparing soleus H reflex latency with stimulation at PF and GF. Results in 10 subjects showed muscle afferent CV of 57.6, cutaneous afferent CV of 55.1, motor CV of 52.4. and mixed nerve CV of 56.3 m/s. Although statistically significant, these differences are much smaller than in animal studies. These results have implications for understanding what fibers contribute to Spinal reflexes. © 1994 John Wiley & Sons, Inc.     

卒中后患者上肢体感诱发电位及周围神经电生理特征分析

目的 分析卒中后患者上肢体感诱发电位（somatosensoryevokedpotentials,SEP）、周围神经电生理特征与运动功能的相关性。方法 此前瞻性研究连续纳入2018年6月—2022年3月康复科收治的亚急性期卒中患者,采用自身健患侧进行对比,进行双侧上肢SEP和周围神经电生理检查并对患侧上肢运动功能进行评分。分析患侧SEPP15、N20、P25、N13及N9潜伏期、感觉神经传导参数、运动神经传导参数与上肢运动功能等指标的相关性。结果 本研究共纳入卒中后亚急性期偏瘫患者102例,平均（68.76±11.33）岁,男性78例。患者偏瘫侧上肢SEPP15[(16.90±1.67)ms vs.(16.27±1.50)ms,P<0.001]、N20[(20.13±1.49)ms vs.(19.42±1.60)ms,P<0.001]、P25[(24.39±1.75)ms vs.(23.70±1.50)ms,P<0.001]、N13[(14.05±1.25)ms vs.(13.42±1.26)ms,P<0.001]及N9[(9.25±0.96)ms vs.(8....     

A new technique for dorsal sural nerve conduction study with surface strip electrodes

ObjectiveTo obtain higher amplitude of dorsal sural sensory nerve action potentials (SNAPs), we used a new method for dorsal sural nerve conduction study with surface strip electrodes (SSEs).MethodsDorsal sural SNAPs were recorded orthodromically. The recording electrodes were placed behind the lateral malleolus. SSEs were attached to the laterodorsal aspect of the foot for stimulation of the dorsal sural nerve (DSN). We also used a conventional method with a standard bipolar stimulator and compared the findings.ResultsDorsal sural SNAPs were recordable bilaterally from 49 healthy volunteers. Mean peak-to-peak amplitude for SNAPs was 12.9 ± 6.3 μV, and mean nerve conduction velocity was 44.8 ± 5.5 m/s. The mean amplitude of SNAPs obtained by our method was 118.6% higher than that of SNAPs obtained by the conventional method (12.9 μV vs. 5.9 μV; P < 0.001).ConclusionsThe highest amplitude of dorsal sural SNAPs was constantly obtained by SSEs since SNAPs arising from whole digital branches of the DSN could be elicited by placement of SSEs.SignificanceWhen the DSN supplies more cutaneous branches to the lateral half of the foot, SSEs gives higher amplitude of dorsal sural SNAPs than that of the standard innervation type.