F-wave latency,the most sensitive nerve conduction parameter in patients with diabetes mellitus

In this study we examined the diagnostic sensitivity of minimal F-wave latency, F-wave persistence, motor nerve conduction velocity (MCV), and amplitude of the compound motor action potential (CMAP) of the median, ulnar, tibial, and peroneal nerves, and of sensory conduction velocity (SCV) and sensory nerve action potential (SNAP) amplitude of the sural nerve in 82 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, and for all four motor nerves the Z scores of the minimal F-wave latency were significantly larger than those of the amplitude of the CMAP. The Z scores of the peroneal minimal F-wave latency exceeded those of peroneal MCV, sural SCV, and sural SNAP. F-wave persistence did not differ significantly from the reference values. In conclusion, minimal F-wave latency is the most sensitive measure for detection of nerve pathology and should be considered in electrophysiological studies of diabetic patients. © 1997 John Wiley & Sons, Inc. Muscle Nerve 20: 1296–1302, 1997     

多发性硬化周围神经病变的电生理评价

目的研究多发性硬化(MS)患者的周围神经病变，并评价神经电生理技术的应用价值。方法采用神经传导速度(NCV)技术检测MS患者周围神经的运动传导速度(MCV)、感觉传导速度(SCV)及其潜伏期；采用运动诱发电位(MEP)检测正中神经和胫神经的潜伏期；采用F波检测正中神经的出现率和传导速度。结果MS患者NCV均不同程度地减慢，MCV的异常率高于SCV，NCV结果提示轴突损害比脱髓鞘显著。MEP测得肘点和腰4点的潜伏期延长，提示正中神经远端和腰骶神经根功能的损害。部分患者F波的出现率降低．提示周围神经根功能异常。结论MS患者存在周围神经病变；综合运用电生理技术可以全面地评价MS周围神经功能。     

磁刺激运动诱发电位在多发性周围神经病中的诊断价值

对１２例多发性周围神经病患者进行磁刺激运动诱发电位（ＭＥＰ）测定，同时测定感觉神经传导速度（ＳＣＶ）、运动神经传导速度（ＭＣＶ）及Ｆ波。结果发现，ＭＥＰ潜伏期异常率为７５％，高于ＳＣＶ（６６．７％）和ＭＣＶ（５８．２％）及Ｆ波（６０％）；至少有１项ＭＥＰ指标异常者１１例，占９１．７％。分析认为，ＭＥＰ异常率较高的原因在于它可以对包括神经根在内的周围神经全长进行测定。将ＭＥＰ各项指标综合分析可提高ＭＥＰ的阳性率。ＭＥＰ对周围神经病是一项有较大价值的辅助检查手段。     

91例肌萎缩侧索硬化症的F波和神经传导研究

目的探讨肌萎缩侧索硬化症(ALS)F波和神经传导改变的特点.方法所有患者均采用常规方法测定感觉神经传导速度(SCV)、运动末端潜伏期(distal motor latency,DML)和F波,后者的测定包括潜伏期和/或传导速度及出现率.分析了DML和复合肌肉动作电位(compound muscle action potential,CMAP)波幅、F波出现率与肌力的关系.结果在91例ALS患者中,仅有3例SCV异常;正中神经、尺神经及胫后神经DML延长者分别占16.7%、13.8%、7.1%,CMAP波幅下降者分别占50.0%、44.6%、28.6%;5.0%患者F波传导速度异常,48例患者F波出现率下降,其中19例出现率为0.肌力下降者DML、CMAP波幅及F波出现率改变明显.结论ALS患者可出现DML延长和CMAP波幅降低,二者比较后者的改变更显著;F波传导速度相对正常而出现率下降明显;DML、CMAP波幅及F波出现率的异常与肌力明显相关(P均＜0.01).     

神经型布氏杆菌病周围神经损害的临床与电生理研究

目的研究神经型布氏杆菌病周围神经损害的临床特征,探讨电生理对其的诊断价值。方法对32例神经型布氏杆菌病周围神经损害患者(病例组)和32名性别及年龄与病例组匹配的正常对照组进行神经电生理检查,并对所得检查结果进行统计学分析。结果病例组与对照组在运动末梢潜伏期(distal motor latency,DML)、复合肌肉动作电位(compound motor active potentials,CMAP)波幅、运动神经传导速度(motor nerve conduction velocity,MCV)、感觉神经动作电位潜伏期(sensory nerve action potential latency,SL)、感觉神经动作电位(sensory nerve action potential,SNAP)波幅及感觉神经传导速度(sensory nerve conduction velocity,SCV)方面的比较,差异均有统计学意义(P0.05)。电生理检查提示上下肢周围神经损害,感觉神经及运动神经均受累,其中感觉神经占55.47%,运动神经占16.80%,上肢以正中神经(64条)最多见,下肢以腓肠神经(16条)最多见。四肢运动神经256条中43条传导速度减慢,占16.80%,四肢感觉神经256条中142条传导速度减慢,占55.47%,SCV较MCV改变明显,上肢病变重于下肢。结论神经电生理检查为神经型布氏杆菌病周围神经损害的临床诊断提供了客观依据。     

Symmetry and temporal variability of neurography]

The aims of the present study are to document side-to-side differences and temporal variability, between two trials (T1 and T2 at a time interval of 3 months) of nerve conduction measurements collected from 30 healthy subjects (mean age 22 +/- 2 years). METHODS: The protocol at T1 consisted of motor nerve conduction studies of median, ulnar, peroneal and tibial nerves bilaterally, with measurement of (a) motor response size (amplitude and area); (b) terminal latency; (c) minimal, mean and maximal F-wave latency; (d) motor conduction velocity; and (e) F-wave occurrence. T1 also involved sensory nerve conduction studies of median, ulnar, radial, lateral and medial cutaneous, sural and superficial peroneal nerves bilaterally, with measurement of sensory potential size (amplitude and area) and computation of sensory conduction velocity. The protocol at T2 consisted of identical measurements from the dominant side. RESULTS AND CONCLUSION: There was a negative relationship between the variability of parameters evaluating nervous conduction and the length of the nerve segment under study. Thus, the smallest side-to-side and temporal variabilities are measured for minimal F-wave latencies (on average 2-3%). The limits of symmetry and temporal variability are particularly useful for diagnosis of unilateral peripheral neuropathy or neurophysiological follow-up of patients with neuropathy, when the variability of the parameter under study is weak and when there is a high correlation between values recorded on the left and on the right or at T1 and T2. This was the case for motor response size of tibial and ulnar nerves, sensory potential size of radial nerve and minimal F-wave latencies from each studied motor nerve.     

Reproducibility in nerve conduction studies and F-wave analysis.

OBJECTIVE: Reproducibility testing of nerve conduction studies and F-wave latencies in a group of healthy volunteers. METHODS: A total of 32 healthy volunteers underwent sensory and motor nerve conduction studies of the ulnar and tibial nerves, including F-waves, elicited by 32 stimuli, repeated in two different days by the same examiner. RESULTS: The F-wave latencies showed less variability than the other parameters of conduction studies, and, among them, the F-wave mean latency of the tibial nerve has been the one with the higher reproducibility. CONCLUSIONS: F-wave latencies were the parameters with best reproducibility, followed by conduction velocities and amplitudes. SIGNIFICANCE: Our data showed that the F-wave mean latency is a parameter with a high reliability, considering the reproducibility, for sequential studies.     

Distal motor latency and residual latency as sensitive markers of anti-MAG polyneuropathy

There is debate whether the terminal latency index (TLI) is a sensitive marker for polyneuropathy with anti-myelinassociated-glycoprotein antibodies (anti-MAGP). We examined 6 patients with an anti-MAGP and 6 patients with a chronic inflammatory demyelinating polyneuropathy (CIDP). The electroneurographic features studied were: distal compound motor action potential (CMAP), distal motor latency (DML), motor conduction velocity (MCV) elbow to wrist (distal MCV), MCV axilla to elbow (proximal MCV), MCV distal/proximal, terminal latency index (TLI), residual latency (RL), F-wave, and modified F ratio.We found significant differences between anti-MAGP and CIDP for DML and for RL.No significant differences were found for TLI and the other measures. The TLI values were not significant probably because our patients had a longer duration of disease,which supports the hypothesis of a distal to proximal progression of conduction slowing over time. We propose that a residual latency >4.0 and a distal motor latency >7.0 are strongly suggestive for an anti- MAGP.     

Is Ross syndrome a dysautonomic disorder only? An electrophysiologic and histologic study.

OBJECTIVE: To define the involvement of peripheral nerve fibers in Ross syndrome. METHODS: Mechanical pain perception, tactile and thermal thresholds on hand, foot dorsum, thigh, median nerve orthodromic sensory conduction velocity (SCV) and motor conduction velocity (MCV), sural nerve antidromic SCV, peroneal nerve MCV, H-reflex, F-wave, median, tibial nerve somatosensory evoked potentials (SSEPs), perioral, hand CO(2) laser late (LEPs) and ultralate evoked potentials, sympathetic skin response (SSRs), cardiovascular, Minor sweat, silastic imprint, histamine, photopletysmographic and pupil pilocarpine tests, cutaneous innervation immunohistochemical techniques were studied in 3 patients with Ross syndrome. RESULTS: Quantitative sensory testing showed altered results in patients 1 and 2, and patient 3 had a slight impairment of mechanical pain perception. Nerve conduction, except for a median nerve distal reduction of sensory conduction in patient 1, F-wave and SSEP findings were normal; H-reflex was absent at rest in all patients. Hand LEPs were absent in patient 2, ultralate potentials were absent in patients 1 and 2. Skin biopsy showed a disease duration related reduction of unmyelinated and myelinated sensory fibers and a lack of unmyelinated autonomic fibers in all patients. CONCLUSIONS: Our data suggest that Ross syndrome is a degenerative disorder involving progressive sudomotor fibers, and then epidermal sensory unmyelinated and myelinated fibers.     

糖尿病性周围神经病患者的神经电图改变

目的 观察糖尿病性周围神经病（DPN）患者神经电图的改变。方法 对78例DPN患者进行神经电图检查,包括运动神经传叶速发（MCV）、感觉神经传导速度（SCV）和F波检查。结果 共检查78例患者的468条神经,其中MCV减慢166条,MCV减慢合并远端潜伏期延长39条,异常率43．8％;SCV减慢175条,末引出电位75条,SCV减慢兼远端潜伏期延长26条,异常率58．9％．检查102条神经的F波,其中异常66条,异常率为64．7％,12条神经（11．8％）F波时间离散度增加。结论 神经电图是诊断DPN的敏感及特异性的检查,多个参数相结合有助于提高阳性检出率。     

An electrophysiological severity scale in tarsal tunnel syndrome

OBJECTIVE: To propose a neurophysiological classification of tarsal tunnel syndrome. MATERIAL AND METHODS: We retrospectively reviewed the medical records of two electromyography laboratories. Case inclusion criteria were based on clinical parameters. Motor conduction velocity, distal motor latency (DML), sensory conduction velocity (SCV) and sensory action potential (SAP) from big toe (T1) and from fifth toe (T5) to medial malleolus were measured in the medial and plantar nerves. When SCVs of T1 and T5 were normal, we considered the difference in T1 SCV between affected and unaffected side and in T1 SCV of the affected side with sural nerve distal SCV. Feet with TTS were classified in six electrophysiological classes: 0, normal SCV and DML; 1, normal absolute SCV with abnormal comparative tests; 2, slowing of T1 and T5 SCV and normal DML; 3, slowing of SCV and DML; 4, absence of T1 and T5 SAPs and abnormal DML; 5, absence of sensory and motor response. RESULTS: A total of 111 feet belonging to 96 patients (27 men, 69 women; mean age 49.6 years) were diagnosed with TTS. T1 and T5 SCV were abnormal in 82 and 73% of cases, respectively, and comparative tests were abnormal in a further 7% of cases. DML was abnormal in 82 feet (73.9%). Eight feet (7%) were without neurographic abnormalities. The distribution of feet in neurophysiological classes was: stage 0, 7%; stage 1, 9%; stage 2, 10%; stage 3, 39%; stage 4, 32%; stage 5, 3%. Higher clinical scores coincided with higher neurographic classes. CONCLUSION: The progression of neurographic abnormalities in TTS reflects the relation between SCV and DML, and between neurographic values and clinical severity. The scale assigns severity classes in a reliable and non-arbitrary way. This classification can easily be used by electrophysiological laboratories with their own electrophysiological techniques and normal values.     

Comparison of motor conduction techniques in the diagnosis of carpal tunnel syndrome

OBJECTIVE: To compare the sensitivities of motor wrist-to-palm (W-P) conduction velocity and two median-ulnar motor latency differences with that of sensory W-P conduction velocity in the diagnosis of carpal tunnel syndrome (CTS). METHODS: This study included 116 consecutive patients with CTS (160 hands) referred for evaluation and 100 volunteers who served as controls. Median motor and sensory nerve responses with wrist and palm stimulation allowed for the determination of motor and sensory W-P CV (W-P MCV and SCV). Two motor distal latency (MDL) differences between the median-thenar and ulnar-hypothenar (M-U) muscles and between the median-second lumbrical and ulnar-interossei muscles (2L-INT) were measured and calculated. The mean values of controls plus or minus 2.5 SD served as the normal limits. RESULTS: Among the 160 hands with suspected CTS, 11 (6.88%) had normal electrodiagnostic studies and 149 (93.1%) had at least one abnormal electrodiagnostic study. Among the 149 hands with an abnormality, 139 (86.88%) had abnormal W-P MCV and 129 (80.63%) had abnormal W-P SCV. The sensitivity for 2L-INT was 77.5%, and it was 70% for M-U, 68.75% for median MDL, and 73.75% for sensory distal latency. Combining W-P MCV and W-P SCV allowed for the detection of abnormalities in 147 hands (91.88%) and yielded a markedly improved diagnostic rate compared with W-P SCV alone. CONCLUSION: Motor W-P conduction study is more valuable and no more difficult than sensory W-P conduction study for the diagnosis of CTS. In patients with suspected CTS in whom the results of conventional nerve conduction studies are normal, studying both motor and sensory W-P conduction increases the diagnostic yield.     

肌萎缩侧索硬化患者205例的神经传导特点分析

目的 分析肌萎缩侧索硬化(ALS)患者的神经传导和F波特点,并探讨其与肌力、病程和首发部位等之间的关系.方法 收集于1997年1月至2008年5月期间我院门诊或病房收治的ALS患者205例,均采用常规肌电图检查,测定其运动神经传导、F波以及感觉神经传导(SCV).结果 在205例ALS患者中,仅有3例SCV异常,正中神经、尺神经及胫后神经末端潜伏期(DML)延长者分别占24.9%(48/193)、15.3%(25/163)、21.2%(7/33),复合肌肉动作电位(CMAP)波幅下降者分别占57.0%(110/193)、49.7%(81/163)、39.4%(13/33);68.9%(122/177)患者F波出现率下降,其中31.1%(55/177)F波出现率为0,肌力下降者DML、CMAP波幅及F波出现率改变明显.肢体起病组正中神经CMAP波幅下降[81.5%(53/65)]和F波异常率[70.9%(44/62)出现率下降,45.1%(28/62)出现率为0]较延髓部起病者[32.4%(11/34);F波38.2%(13/34)出现率下降,14.7%(5/34)出现率为0]更明显,两组比较差异有统计学意义(x2=23.629、9.753、9.029,均P<0.01);DML异常两组间差异无统计学意义.Logistic回归分析显示CMAP波幅的降低与上肢远端肌力、首发部位、病程显著相关,F波出现率的降低与上肢远端肌力、首发部位相关.结论 ALS患者可出现DML延长和CMAP波幅降低(后者改变更显著),F波出现率明显下降而传导速度相对正常;DML、CMAP波幅及F波出现率的异常与肌力明显相关.首发部位为肢体和(或)上肢远端肌力下降者CMAP波幅及F波异常率更明显.

Abstract：

Objective To investigate the F-wave and nerve conduction in patients with amyotrophic lateral sclerosis (ALS) and explore the correlation between these parameters and muscle strength, disease duration and onset site.Methods The data of outpatients and inpatients diagnosed with ALS were collected in Peking Union Medical College Hospital from January 1997 to May 2008.Standard sensory and motor nerve conduction study of the median nerve, ulnar nerve and tibial nerve was performed in 205 patients with ALS.F-wave velocity and frequency was measured in median nerve.Parameters for analyses included sensory conduction velocity and amplitude, distal motor latency (DML), and compound muscle action potential (CMAP) amplitude.Correlation between muscle strength and DML, CMAP amplitude or F-wave frequency were also explored.Results Delayed DML of the median nerve, ulnar nerve and tibial nerve were found in 24.9% (48/193), 15.3% (25/163), 21.2% (7/33) of patients respectively.Decreased CMAP amplitudes were found in 57.0% (110/193), 49.7% (81/163), 39.4% (13/33) of patients respectively.Decreased F-wave frequency of the median nerve was found in 68.9% (122/177) of patients.The abnormality of DML,CMAP amplitude and F-wave frequency of median nerve were increased in weaker muscles.Decreased median nerve CMAP amplitude (81.5% (53/65)) and F-wave abnormality (decreased persistence 70.9%(44/62), absent responses 45.1% (28/62)) in spinal onset groups were significantly higher than those in bulbar onset groups (CMAP 32.4% (11/34); F-wave: decreased persistence 38.2% (13/34), absent responses 14.7% (5/34); x2 = 23.629, 9.753, 9.029,all P <0.01).Compared with the bulbar onset group,the abnormality of DML in spinal onset group was higher, but not reach statistical significance.Logistic regression revealed a strong direct association between decreased CMAP amplitudes and upperextremity muscles strength, disease duration and onset symptom.Abnormality of F-wave frequency was associated with upper-extremity muscles strength and onset symptom.Conclusions Delayed DML and decreased amplitude of CMAP are found in ALS patients.CMAP amplitude is a sensitive parameter related to the severity of ALS.F-wave velocity is relatively normal while F-wave frequency of the median nerve is correlated with muscle strength.Decreasing CMAP amplitude and F-wave frequency are correlated strongly with muscle weakening,disease duration and symptom onset over limbs.     

Ten-year follow-up of peripheral nerve function in patients with familial amyloid polyneuropathy after liver transplantation

Background   The electrophysiological long-term effects of liver transplantation on peripheral nerve function in patients with familial amyloid polyneuropathy (FAP) have not been evaluated. Methods   Eight FAP patients with a proven ATTRVal30Met gene were observed for 10 years after liver transplantation. We performed repeated measurement of maximal motor nerve conduction velocity (MCV), distal latency, size of compound muscle action potential (CMAP) and maximal sensory nerve conduction velocity (SCV) in both the ulnar and tibial nerves. We also recorded the coefficients of variance in the R-R interval on the electrocardiogram (CV_R-R). Results   Some autonomic symptoms subsided but motor and sensory symptoms 10 years after transplantation were either slightly improved or almost the same as before surgery in 7 of 8 patients. These 7 have returned to their previous social lives including their jobs. The MCV of the tibial nerve slightly improved, and other parameters of motor and sensory nerve function and CV_R-R did not show any deterioration during the 10-year observation period. Conclusions  Liver transplantation can halt the progression of peripheral neuropathy in FAP patients.     

Peripheral neuropathy response to erythropoietin in type 2 diabetic patients with mild to moderate renal failure

This study assessed the added effect of 6 months of erythropoietin (EPO) administration in patients suffering from diabetic neuropathy with mild to moderate chronic kidney disease (CKD) managed with gabapentin. Twenty diabetic patients with mild to moderate CKD were included; 12 in gabapentin and 8 in EPO+gabapentin group. The subjects underwent nerve conduction studies (NCS) at the initiation of the investigation and after 6-month treatment. NCS were made in deep and superficial peroneal, tibial, and sural nerves. After 6 months, in both the groups, proximal motor latency (PML) nonsignificantly improved in deep peroneal and tibial nerves; conversely, dorsal motor latency (DML) got slightly impaired in these two nerves. A nonsignificant disruption and improvement was observed in deep peroneal and tibial motor nerve conduction velocity (MNCV), respectively, in gabapentin group. Although the F-wave of tibial and deep peroneal nerves remained stable in gabapentin group, a nonsignificant improvement was observed in EPO+gabapentin group. H-reflex of tibial nerve and all the evaluated parameters of sural and superficial peroneal nerves remained constant in all patients. Thus, it can be concluded that 6-month administration of EPO+gabapentin, or gabapentin alone in mild to moderate CKD patients with diabetic neuropathy could not improve nerve performance.     

Comparison of sensitivity of transcarpal median motor conduction velocity and conventional conduction techniques in electrodiagnosis of carpal tunnel syndrome.

OBJECTIVE: To compare the sensitivity of median wrist-palm motor conduction velocity (W-P MCV) with those of standard sensory conduction techniques in the electrodiagnosis of carpal tunnel syndrome (CTS). METHODS: This study included 280 consecutively suspected CTS patients (360 hands) referred for evaluation and 150 volunteers who served as controls. We determined and calculated (1) median W-P MCV, (2) median motor distal latencies (DL) and median sensory DL for (3) thumb (D1), (4) index (D2) and (5) ring finger (D4), (6) median wrist-palm sensory conduction velocity (W-P SCV) and sensory conduction time (W-P SCT) for index finger and sensory latency differences between (7) median-radial (M-R) for thumb and (8) median-ulnar (M-U) nerves for ring finger. The normal limits were calculated from the median of normal controls +/-2.5 standard deviations. The sensitivities of each test were determined and compared. RESULTS: Among the 360 hands with suspected CTS, 32 hands (8.9%) had normal electrodiagnostic studies and 328 (91.1%) had at least one abnormal electrodiagnostic study. Among the 328 hands with abnormalities, 234 (65%) had abnormal motor DL and 294 (81.7%) had abnormal W-P MCV. The sensitivity was 80.3% for D1, 72.5% for D2, 76.7% for D4, 86.7% for M-R (specificity, 98.7%), 87.2% for M-U (specificity, 96.7%), 80.8% for sensory W-P SCT and 73.6% for W-P SCV. CONCLUSIONS: W-P MCV is a valuable motor conduction technique for the diagnosis of CTS and it is confirmed again that W-P MCV is equal to or more sensitive than W-P SCV and W-P SCT. Furthermore, the findings of the present study are in agreement with the conventional wisdom that internal comparison of latency differences between median and ulnar or radial nerves is the best method for a diagnosis of patients with suspected CTS. Therefore, we recommend that CTS patients be studied according to the following steps: (1) routine sensory and motor DL, (2) if step 1 is negative, then perform and determine W-P MCV or SCT. This may increase the diagnostic yield of 10%, (3) if step 2 is negative, measure the M-U or MR. These are the final and more sensitive techniques in making a diagnosis with an additional diagnostic yield of 10%. SIGNIFICANCE: We provide the evidence of W-P MCV that could be a standard technique for electrodiagnosis of CTS. Furthermore, we make a reasonable flow chart and recommendation for electrodiagnosis of CTS for electromyographers.     

Peripheral neuropathy in patients with beta-thalassaemia.

As some patients with beta-thalassaemia manifested neurological signs, clinical and electrophysiological investigations were carried out on 53 thalassaemic patients and 29 healthy control subjects. Twenty per cent of the patients showed clinical and electrophysiological findings of a mild peripheral sensorimotor neuropathy, mainly of the lower limbs. The clinical symptoms were numbness, pins and needles sensations, muscular cramps, myalgia and muscle weakness. The electrophysiological abnormalities were manifested by decreased motor conduction velocity (MCV) and prolonged F-wave latencies of the tibial and the peroneal nerves. Borderline increase in the latencies of the sensory potentials of the median nerve was also observed. The electromyographic findings of the patients with diminished MCVs were compatible with a predominantly motor peripheral neuropathy. This neuropathy appears during the second and third decade of life.     

腓骨肌萎缩症1型18例电生理分析

目的分析腓骨肌萎缩症1型（Charcot-Marie-Tooth病,CMT1）电生理特点。方法应用肌电图仪检测和分析来自12家系18例CMT1型病人的电生理特征,包括肌电图（EMG）、运动神经传导速度（MCV）和感觉神经传导速度（SCV）。结果15例的病人肌电图上出现纤颤、正相电位,15例病人有运动电位时限延长。正中神经SCV有13例未测出,而对应的MCV只有1例未测出。腓总神经、胫神经的MCV分别有9、10例未测出而正中神经MCV只有1例未测出。结论电生理特点为下肢神经病变重于上肢,感觉神经病变重于运动神经。感觉、运动神经均受累,不同病人受累程度不一致;CMT1型病人同一家系,表现存在差异。     

急性河豚毒素中毒患者神经电生理的研究

目的 研究急性河豚毒素（TTX）中毒患者神经电生理的改变。方法 检测58例TTX中毒患者的肌电图，运动神经传导速度（MCV），感觉神经传导速度（SCV），F波，H反射和体感诱发电位（SEP）。结果 22例TTX中毒患者（37．9％）肌电图以多相不规则波为主，MCV，SCV均有减慢，以SCV减慢最为显著，MCV远端动作电位潜伏期明显延长，神经传导速度（NCV）的异常率比纤颤，正尖波检出率高，F反应，H反射异常提示部分TTX中毒累及神经根；SEP的异常率达56．9％。结论 TTX中毒可伴有中枢神经的损害。神经电生理检测可用来动态观察其神经系统损害程序，病程，范围，亦是TTX中毒时早期检查的重要手段之一。     

138例糖尿病患者神经电图分析

目的探讨2型糖尿病患者周围神经病变(DPN)的神经电生理特点及其与病程的关系。方法连续记录138例血糖控制良好的糖尿病患者神经电图(包括感觉神经传导速度SCV和运动神经传导速度MCV)的检测结果,并根据糖尿病病程将其分组进行比较。结果共检测周围神经1669条,异常神经313条(18.75%),下肢异常率(132/530,24.9%)明显高于上肢(59/517,11.4%)(P<0.0001),感觉神经(122/622,19.6%)与运动神经(191/1047,18.2%)受累无差异(P=0.5665);糖尿病病程10年以上者运动、感觉神经异常率(24.3%,33%)明显高于病程小于10年组(14.2%,14%)(P<0.001)。病程大于10年组神经传导速度均较病程小于10年组减慢,正中神经、胫后神经运动传导速度和尺神经、腓肠神经感觉传导速度有统计学意义(P<0.05);除尺神经外所查运动神经近远端复合肌肉动作电位波幅(CAMP)病程≥10年组均明显低于病程<10年组。结论尽管受检时血糖控制良好,但依然有周围神经电生理异常变化。2型糖尿病患者下肢神经传导异常率高于上肢,尤以运动神经明显。病程是糖尿病周围神经损害的危险因素,随着病程增加神经传导异常率和损伤严重程度增高。