环指感觉神经传导速度检测对诊断轻度腕管综合征的价值

目的：探讨环指感觉神经传导速度（SCV）测定对诊断轻度腕管综合征（CTS）的敏感性。方法：临床症状体征符合CTS,正中神经运动末端潜伏期正常的59例（62手）患者和50名（100手）年龄性别相匹配的健康对照参与本研究,采用顺向SCV测定法分别测定环指（指4）正中神经和尺神经SCV,指3正中神经SCV。结果：指4尺神经SCV〉46．6m／s,指4正中神经SCV〈44．6m／s,和（或）尺神经SCV与正中神经SCV差值〉8．1m／s（x＋2s）,符合CTS。正中神经SCV指3测定阳性率为70％,指4测定阳性率为82％,指4正中神经与尺神经SCV差值阳性率为96％。指4刺激可在29例（48手）患者腕部正中神经处记录到双峰电位,对照组未见。结论：比较指4正中神经和尺神经SCV的差值在鉴别轻度CTS方面是一个非常敏感的方法,腕部正中神经处记录到双峰电位是CTS确诊的明确指标。     

Complete ulnar innervation of the thenar muscles combined with normal sensory fibres in a subject with no peripheral nerve lesion.

A complete ulnar innervation of all thenar muscles, including the opponens, have to our knowledge been described only in patients with severe traumatic lesions of the median nerve. The present study reports a subject with exclusive ulnar innervation of the thenar muscles in the right hand. The patient had no anamnestic or objective signs of peripheral nerve lesions. While his sensory and motor ulnar nerve fibres were normal, electrophysiological examination of the right median nerve showed normal course of the sensory fibres but apparently no motor fibres to the thenar muscles.     

Pattern of sensory conduction in Guillain-Barre Syndrome.

This study in undertaken to evaluate the pattern of sensory conduction abnormalities in Guillain-Barre (GB) Syndrome. Thirty six patients with GB Syndrome following clinical and CSF examination were subjected to motor conduction studies of median, ulnar and paroneal nerves including F wave latencies and sensory conduction studies of median, ulnar and sural nerves bilaterally. Motor conduction abnormalities were seen in 32 out of 36 patients (83%) and were seen more frequently in the lower limbs than upper. Median sensory conduction was abnormal more frequently than ulnar (21 Vs 17 patients). Median sensory conduction was abnormal in 21, ulnar in 17 and sural in 10 patients. In all the patients having abnormal ulnar sensory conduction, median sensory conductions were also abnormal. The patients with abnormal sural conductions had abnormal median sensory conductions in all except one patient. A pattern of normal sural with abnormal median sensory conductions was present in 12 patients. Both sural and median sensory conductions were abnormal in 9 patients and both normal in 14 patients. One patient had abnormal sural conduction with normal median sensory conduction but he had underlying diabetes. A similar pattern was found in relation to ulnar and sural sensory conductions although it was less frequent and less specific. The discordance of sural and median sensory conduction is important in GB Syndrome. Normal sural conductions with abnormal median sensory conductions is suggestive of GB Syndrome in the presence of an appropriate clinical setting, but a reverse pattern should alert an underlying polyneuropathy.     

Comparison of the antidromic sensory nerve action potentials obtained from all fingers on the same hand

Supramaximal compound sensory nerve action potentials (CSNAPs) were recorded antidromically from five fingers of the same hand to electrical stimulation of the median, ulnar, and radial nerves in 17 normal subjects. The mean amplitudes of the median CSNAPs from the thumb, index, and middle fingers were similar in values. There was minimal radial sensory contribution to the thumb, with the mean radial CSNAP amplitude about one-fourth the size of the median CSNAPs. The mean median and ulnar CSNAP amplitudes from the ring finger were approximately half, and the mean ulnar CSNAP amplitude from the little finger was approximately 85%, of the median CSNAP amplitudes from the other fingers. The median, ulnar, and radial sensory nerve conduction velocities were close in values. There appears to be less variability in the population normative data when the size of the CSNAPs is expressed in terms of amplitude ratio rather than in absolute amplitude value.     

Somatosensory evoked potentials for the diagnosis of proximal sensory median neuropathy with preserved distal sensory action potential

A 33 year-old-man with paresthesia in first three fingers of the right hand after minor trauma of the arm was examined electrophysiologically. The proximal sensory median neuropathy was isolated which it is unusual in traumatic lesion. Motor and distal sensory conduction studies were normal but sensory evoked potentials (SEPs) were abnormal by right median nerve stimulation at the wrist level with decrease in amplitude of peripheral potential at the Erb's point, the cervical and contralateral parietal levels. This pattern, preserved distal sensory action potential and abnormal peripheral SEPs were suggesting the presence of proximal sensory block conduction without wallerian degeneration. The recovery was complete and fast in correlation with the absence of axonopathy.     

Carpal tunnel syndrome: comparison of the compound muscle action potentials recorded at the thenar region from ulnar and median nerve stimulation

Thenar muscles are primarily innervated by the median nerve. However, compound muscle action potentials (CMAPs) evoked by ulnar nerve stimulation can be recorded at the thenar region due to proximity of some ulnar-innervated muscles, and from volume conduction events. This study was to determine if loss of thenar muscle mass from carpal tunnel syndrome (CTS) could alter the size of ulnar CMAPs obtained at the thenar region, because of changes in the physical surroundings and electrical conductivity. Supramaximal CMAPs were recorded over the thenar eminence to electrical stimulation of the ulnar nerve at the wrist and median nerve at the palm in 102 hands with CTS. Needle EMG was done in the thenar muscles. Severity of needle EMG abnormality was negatively correlated with median-evoked CMAP amplitude (r = -0.76), but not with ulnar-evoked CMAP amplitude (r = -0.12). There was no correlation between the absolute amplitudes of the median and ulnar CMAPs (r = -0.13). Needle EMG abnormality had modest negative correlation (r = -0.43) with median/ulnar CMAP amplitude ratio. Mean median/ulnar CMAP amplitude ratios for normal EMG and for mild, moderate, and severe needle EMG abnormalities were 3.72, 3.31, 1.56, and 0.37, respectively. The absolute amplitude of the ulnar CMAP recorded at the thenar area does not seem to be influenced significantly by the degree of thenar muscle loss (atrophy) from median nerve pathology. However, if the median/ulnar CMAP amplitude ratio falls below 0.5, the study suggests severe loss of motor units in the thenar muscles.     

The origin of the premotor potential recorded from the second lumbrical

PURPOSE: When recording with a palm electrode, a premotor potential (PMP) precedes the compound muscle action potential evoked from the second lumbrical muscle following median nerve stimulation. The origin of the premotor potential has remained uncertain. The aim of this study was to determine whether the PMP-2L is a SNAP derived from antidromically activated digital sensory branches of the median nerve. METHODS: We recorded three active electrodes were placed over the second lumbrical muscle, the third lumbrical muscle, the fourth lumbrical muscle by multi-channel recordings. RESULTS: PMPs are recorded only over the median digital sensory branches after stimulating the median nerve, while they are recorded only over the ulnar branch after stimulating the ulnar nerve. CONCLUSIONS: We conclude that the origin of the PMP is a SNAP arising from antidromically activated digital sensory branches.     

Medical brachial cutaneous nerve conduction study

There is no nerve conduction study for the medial brachial cutaneous nerve in the literature. This study was done in the military hospital # 501 from feb 1st 1997 to june 1st 1999. Three hundred healthy adult (220 male) with a mean age of 40 +/- 13 (range, 14-66) years were studied. At first the sensory nerve action potential of median and ulnar and medial antebrachial cataneous nerves were recorded to show these roots C8-T1 are intact. Then the medial brachial cutaneous nerve was stimulated at the medial border of arm on the line that connects axilla to medial epicondyle (parallel with mid axillary line) there is the juntion site of coracobrachialis muscle to humerus, at the medial border of bicept brachialis muscle, and recording was done on 2 cm above the medial epicondyle. (10 cm under stimulating site). In all of them recording of sensory nerve action potential (SNAP) was done easily and the wave was a biphasic one with the primary negative phase. The latency was 2 +/- 0.3 ms (range, 1.4-2.6) and the amplitude of SNAP was 30 +/- 10 mu v (range, 10-50). The nerve conduction velocity was 61 +/- 4 m/s (range, 53-69). We think with regard of the intensity and site of stimulation and recording area this wave is not due to compound nerve action potential of median or ulnar nerve. This study may be useful in evaluation of T1 root and in the difference of medial cord and lower trunk lesions with the ulnar and medial part of median nerve injury.     

腓骨肌萎缩症患者的临床与神经电生理特征分析

目的:探讨腓骨肌萎缩症(Charcot-Marie-Tooth disease,CMT)的临床与神经电生理特征;方法:应用肌电图仪检测和分析21例腓骨肌萎缩症患者的电生理特征,包括肌电图和运动、感觉神经传导速度;分析电生理特征与临床之间的关系;结果:16例患者肌电图出现纤颤电位和(或)正锐波,17例患者运动单位(MUP)时限延长。11例腓总神经、13例胫神经运动传导速度(MCV)未引出,1例正中神经、2例尺神经MCV未引出,3例正中神经、2例尺神经MCV正常,其余均有不同程度减慢;15例腓肠神经感觉神经传导速度(SCV)未引出,3例正中神经、6例尺神经SCV未引出,7例正中神经、5例尺神经SCV正常,其余均有不同程度减慢。结论:CMT患者的神经电生理特征大多数呈神经原性损害,运动和感觉神经传导速度有不同程度的受累,下肢的神经病变重于上肢,临床表现结合神经肌电图检查有助于CMT的确诊。     

Mononeuropathy of the suprascapular nerve: study of 3 South American cases

In this work 3 new cases of suprascapular nerve mononeuropathy are described. ENMG diagnosis criteria were: a) normal sensory conduction studies of the ipsolateral ulnar, median and radial nerves; b) bilateral suprascapular nerve latencies with bilateral compound muscle action potential, obtained from the infraspinatus muscle with symmetrical techniques; and c) abnormal neurogenic infraspinatus muscle electromyographic findings, coexisting with normal electromyographical data of the ipsolateral deltoideus and supraspinatus muscles. These 3 cases of suprascapular mononeurpathy were found in 6,080 ENMG exams from our University Hospital. For us this mononeuropathy is rare with a 0.05% occurrence.     

正中和尺掌-腕混合神经潜伏期差在腕管综合征诊断中的应用

目的:评估正中和尺掌-腕混合神经潜伏期差在腕管综合征(CTS)诊断中的应用价值。方法:选取2019年1月至2019年12月在常熟市中医院门诊诊断为CTS的患者47例(77只手掌)作为研究组,同时收集同时段在体检中心健康检查的志愿者46名(69只手掌)作为对照组,分别记录正中神经腕-拇短展肌的远端运动潜伏期(DML)、腕-中指的感觉神经传导速度(SCV)、感觉神经动作电位(SNAP)波幅及正中和尺掌-腕混合神经潜伏期差(ΔDSL)。结果:研究组与对照组比较,腕-拇短展肌DML延长[(4.49±0.97)ms比(3.16±0.42)ms],腕-中指SCV减慢[(42.62±7.35)m/s比(60.65±6.70)m/s],SNAP波幅下降[(11.89±8.05)μV比(22.07±7.22)μV],正中和尺掌-腕混合神经ΔDSL延长[(0.84±0.34)ms比(0.23±0.10)ms],差异均具有统计学意义(P<0.05)。腕-拇短展肌DML、腕-中指SCV、正中和尺掌-腕混合神经ΔDSL诊断特异度分别为97.1%、100%、98.6%(P>0.05),诊断敏感度分别为66.2%、59.2%、90.1%(P<0.05)。结论:正中和尺掌-腕混合神经ΔDSL用于诊断CTS是比较敏感的,尤其可以提高早期CTS的阳性检出率。     

F wave parameters and F tacheodispersion in mild diabetic neuropathy

F tacheodispersion and some F wave parameters have previously been suggested to be useful in the detection of peripheral nerve involvement in diabetic patients with normal nerve conduction studies. In this study, ulnar and tibial F wave parameters of diabetic cases with normal motor and sensory nerve conduction studies (Group 1) were calculated, F tacheodispersion histograms were constructed and compared with the same parameters obtained from the normal controls (Control group) and diabetic cases with abnormal motor and sensory nerve conduction examinations (Group 2). There was a tendency towards lower conduction velocities in ulnar and tibial tacheodispersion histograms of Group 1 and Group 2, as compared to Control group. Most of the F wave values were significantly abnormal in Group 2 in comparison to other two groups, whereas statistically significant differences between Group 1 cases and Control group were found in minimum ulnar F wave conduction velocity (FCVmin), mean ulnar FCV (FCVmean), tibial FCVmin and tibial FCVmean values. Unlike other methods, F waves give information about the entire length of the motor nerve fiber. In mild neuropathies, in which nerve fibers are damaged uniformly, testing the whole length of a nerve with this method may be beneficial in detection of a mild conduction abnormality.     

肯尼迪病患者的神经电生理分析

目的:研究肯尼迪病患者的神经电生理特点,提高对此病电生理的认识。方法:对经基因确诊的3例肯尼迪患者的神经电生理进行总结分析。3例患者均行神经传导和肌电图(EMG)检测。神经传导检查包括:正中神经、尺神经、腓总神经、胫神经和腓肠神经。检测项目包括运动神经潜伏期(Lat)、复合肌肉动作电位波幅(CMAP)、运动神经传导速度(MCV);感觉神经潜伏期(lat)、感觉神经动作电位波幅(SNAP)、感觉神经传导速度(SCV)。EMG:检查双侧舌肌、胸锁乳突肌、三角肌、第一骨间肌、胸椎旁肌、股四头肌、胫前肌。检测项目包括静止时的自发电位,轻收缩时运动单位动作电位(MUP)的时限、波幅,重收缩时的募集相。结果:第1例患者运动神经传导正常,感觉神经SNAP波幅低和SCV正常。第2例患者双正中神经运动Lat延长、CMAP下降,NCV减慢,双正中神经感觉未测及SNAP波幅,合并腕管综合征;其余运动神经传导正常,感觉神经SNAP波幅和SCV均低。第3例运动神经传导正常,感觉SNAP波幅低和SCV下降。本组3例患者EMG多块肌肉静息时出现2处以上的纤颤波、正尖波,轻收缩时MUP时限增宽,波幅增高,部分呈巨大电位,重收缩时呈单纯相或单纯混合相。结论:KD患者EMG呈广泛神经源性改变,可累及感觉。     

Carpal tunnel syndrome: comparison of the median sensory nerve conduction findings from the index and middle fingers

The sensory nerve conduction study (NCS) is a sensitive means for demonstrating the localized median nerve dysfunction at the wrist in carpal tunnel syndrome (CTS). We reviewed the sensory NCS data of 102 patients (178 median nerves) with CTS and tried to determine if there were significant differences in the findings between the index and middle fingers. There was no statistically significant difference in the amplitudes of the compound sensory nerve action potentials (CSNAPs) recorded antidromically from the index and middle fingers during median nerve stimulation at the palm and wrist. Moreover, there was no statistically significant difference in the finger-to-palm and palm-to-wrist sensory nerve conduction velocities (CVs) between the index and middle fingers. The mean CSNAP amplitudes and mean sensory CVs were comparable in values from these two fingers and they showed a high and positive correlation. It appears that the sensory nerves to the index and middle fingers are compromised to a similar degree in CTS, and neither finger will reveal significantly more sensory conduction abnormalities than the other will.     

Electrophysiological assessment in neurogenic thoracic outlet syndrome.

OBJECTIVES: To evaluate the value of different electrophysiological techniques in the diagnosis of neurogenic thoracic outlet syndrome (TOS). MATERIALS AND METHODS: Two females, aged 22 and 30 years, with progressive weakness and wasting of the right hand with slight sensory disturbances. Needle EMG, motor and sensory conduction along median and ulnar nerves, sensory conduction of medial (MACN) and lateral (LACN) antebrachial cutaneous nerves. RESULTS: Chronic neurogenic atrophy in small hand muscles, more severe in lateral part of thenar eminency, reduced compound muscle action potentials (CMAPs) more severe by median than ulnar stimulation, and reduced amplitude of the SNAPs of ulnar and MACN were the main findings consistent with neurogenic TOS. Both patients had right cervical rib in radiography. CONCLUSIONS: Electrophysiological study is useful in the diagnosis of neurogenic TOS. Reduced amplitude of MACN and ulnar nerve SNAPs, predominant denervation in thenar eminency, and reduced amplitude of CMAPs, more by median than by ulnar stimulation, are consistent with the diagnosis.     

掌刺激法在轻度腕管综合症检测中的应用

目的：探讨掌到腕正中神经感觉传导在早期腕管综合症（CTS）诊断中的应用.方法：对临床体征、症状符合腕管综合症（CTS）患者进行常规神经电生理检测.对符合神经电生理腕管诊断正常的患者（即正中神经末梢运动潜伏期DML≤4.5）加做环指刺激法、拇指刺激法、掌到腕正中神经感觉传导（掌刺激法）.结果：掌刺激法中的掌-腕SCV低于41.8m/s考虑诊断为轻度CTS.在三种诊断方法中,掌刺激法敏感度为67％（结合样本量大的相关专业文献中得出的统计数据为敏感度高达100％）,远高于环指刺激法55％和拇指刺激法36％.结论：CTS患者正中神经损害随着病情的进展,损伤由卡压处开始逐步向神经末梢发展,累及正中神经神经末梢,直至重度CTS,导致SNAP消失.腕-掌正中神经感觉神经传导在腕管早期诊断往往非常敏感,掌刺激法中的掌腕SCV低于41.8 m/s考虑诊断为轻度CTS,在患者出现CTS症状,但常规法无法鉴别时,可加做掌刺激法作为常规鉴别诊断.     

Effects of motor cortical stimulation on the excitability of contralateral motor and sensory cortices

Single pulses of transcranial magnetic stimulation (TMS) were applied to the right hemisphere over either the hand sensory area, the hand motor area (M1), ventral premotor area (vPM), dorsolateral prefrontal cortex, or 10 cm away from head (sham stimulation) in order to test the effect on motor evoked potentials (MEPs) elicited by single pulse TMS or transcranial electrical stimulus (TES) over the left M1 or the somatosensory evoked potential (SEP) elicited by an electrical stimulus to the right median nerve. The interstimulus intervals (ISIs) for MEP experiments were 50, 100, 150, 200, 300 and 400 ms, with those for SEP experiments being adjusted for the impulse conduction time from the wrist to the cortex. TMS over the right M1 reduced MEPs elicited by TMS of the left motor cortex at ISIs of 50–150 ms, whereas MEPs produced by TES were unaffected. TMS over M1 and vPM facilitated the contralateral cortical median nerve SEPs at an ISI of 100–200 ms, whereas it had no effect on tibial nerve SEPs or paired median nerve stimulation SEP. Based on these results, we conclude that at around 150-ms intervals, TMS over the motor areas (M1 and vPM) reduces the excitability of the contralateral motor area. This has a secondary effect of enhancing the responsiveness of the sensory cortex through cortico-cortical connections.     

Double pattern of relationship between skin temperature, thermoregulation and sensory nerve conduction

Electroneurographic and thermographic investigations were done in 32 persons. Sensory nerve conduction velocity, amplitude of sensory nerve potential, subjective and objective sensory thresholds were determined during stimulation of each finger. The maximal and minimal skin temperatures for each finger were evaluated from thermograms taken from the dorsal and palmar surface of the hand before and after standard cooling test. The measurements were done in a thermostabilised room at 19-21 degrees C effective ambient temperature. The second degree correlations between the electroneurographic and thermographic parameters were calculated. The statistical analysis revealed the presence of a double correlation pattern depending on the homoiothermic or poikilothermic thermoregulatory ability of the finger. The differentiation threshold criterion for the poikilo- and homoiothermic group assignment was the minimal rest temperature of the finger equal to 28 degrees C. The correlations in the poikilothermic fingers were very strong and much stronger than in the homoiothermic fingers. Correlations with temperatures were strong both at rest as well as after cooling. Correlations for the sensory nerve potential amplitude likewise for the objective and subjective thresholds were stronger than for the conduction velocity. Sensory nerve potential amplitude increases and subjective and objective thresholds decrease with finger temperature. The obtained results suggest that sensory nerve conduction is related not only to the actual tissue temperature but also to local thermoregulatory ability.     

The usefulness of minimal F-wave latency and sural/radial amplitude ratio in diabetic polyneuropathy

The possibility of whether minimal F-wave latency and a simple ratio between the sural and superficial radial sensory response amplitudes may provide a useful electrodiagnostic test in diabetic patients was investigated in this report. To evaluate the diagnostic sensitivity of minimal F-wave latency, the Z-scores of the minimal F-wave latency, motor nerve conduction velocity (MCV), amplitude of compound muscle action potentials (CMAP), and distal latency (DL) of the median, ulnar, tibial, and peroneal nerve were compared in 37 diabetic patients. For the median, ulnar, and tibial nerves, the Z scores of the minimal F-wave latency were significantly larger than those of the MCV. In addition for all four motor nerves, the Z scores of the minimal F-wave latency were significantly larger than those for the CMAP amplitude. Furthermore, 19 subjects showing abnormal results in the standard sensory nerve conduction study had a significantly lower sural/radial amplitude ratio (SRAR), and 84% of them had an SRAR of less than 0.5. In conclusion, minimal F-wave latency and the ratio between the amplitudes of the sural and superficial radial sensory nerve action potential are sensitive measures for the detection of nerve pathology and should be considered in electrophysiologic studies of diabetic polyneuropathy.