Sural nerve conduction studies and late responses in children undergoing hemodialysis

Physiologic evidence of peripheral neuropathy has been described previously in children undergoing hemodialysis. In order to detect early or subclinical evidence of peripheral neuropathy, several newer electrophysiologic techniques, including latencies of late responses (H reflex and F response) and sural nerve sensory studies, were evaluated in addition to routine motor and sensory conduction in 17 randomly selected children (mean age 14.2 years) undergoing hemodialysis (12 of whom had no clinical evidence of peripheral neuropathy) and 20 age-matched normal control subjects. Conventional motor and sensory conduction studies of median and ulnar nerves and motor conduction of peroneal and tibial nerves showed abnormalities of motor conduction in 5 (29%) and abnormalities of sensory conduction in 2 (12%). Sural nerve sensory potentials were abnormal in 10 (59%) patients. Late response were significantly abnormal in 10 (59%) patients, 5 (29%) of whom had normal routine motor conduction studies in the same nerve distribution. The abnormalities of late responses and motor and sensory conduction were more evident in lower limbs. Studies of late responses and sural sensory conduction provide a method of detecting subclinical neuropathy in this patient population at a time when results of conventional motor and sensory conduction tests are within normal limits. Effects of dialysis may then be followed quantitatively in patients whose neuropathy would otherwise be undetectable.     

Electrodiagnostic evidence of subclinical disease states in drug abusers.

One hundred drug abusers, free of clinical signs or symptoms of disease, were examined by electrodiagnostic techniques. Sensory conduction of median, ulnar and sural nerves was evaluated in terms of latency, velocity and amplitude of evoked potential. Motor nerve latencies and conduction velocities of median, ulnar and personeal nerves were determined. Definite changes in the evoked sensory potentials of median and sural nerves of subjects using heroin or LSD were demonstrated. The sensory amplitude changes were suggestive of axonal degreneration because of normal duration. Maximum motor conduction velocity was abnormal in one patient who admitted using a variety of drugs; five heroin and two barbiturate users showed dispersed motor responses suggesting small fiber involvement. No abnormality could be shown in marjuana smokers. Signifcance of these findings is explained, emphasizing important potential for recognition of subclinical abnormalities and the opportunity for disease prevention.     

Sensory nerve action potentials and sensory perception in women with arthritis of the hand

ABSTRACT: BACKGROUND: Arthritis of the hand can limit a person's ability to perform daily activities. Whether or not sensory deficits contribute to the disability in this population remains unknown. The primary purpose of this study was to determine if women with osteoarthritis (OA) or rheumatoid arthritis (RA) of the hand have sensory impairments. METHODS: Sensory function in the dominant hand of women with hand OA or RA and healthy women was evaluated by measuring sensory nerve action potentials (SNAPs) from the median, ulnar and radial nerves, sensory mapping (SM), and vibratory and current perception thresholds (VPT and CPT, respectively) of the second and fifth fingers. RESULTS: All SNAP amplitudes were significantly lower for the hand OA and hand RA groups compared with the healthy group (p < 0.05). No group differences were found for SNAP conduction velocities, SM, VPT, and CPT. DISCUSSION: We propose, based on these findings, that women with hand OA or RA may have axonal loss of sensory fibers in the median, ulnar and radial nerves. Less apparent were losses in conduction speed or sensory perception.     

Peripheral neuropathy associated with the hypereosinophilic syndrome

This case report documents the natural history of the peripheral polyneuropathy associated with persistent hypereosinophilia after treatment with corticosteroids. The neuropathy was documented by nerve conduction studies which revealed reduced amplitude of the sensory and motor evoked responses and slowed conduction velocities that were consistent with axon loss. Sural nerve biopsy revealed mild axonal loss distally without eosinophilic infiltration. The patient was treated with high-dose corticosteroids with a rapid normalization of his eosinophil count. Neurologic examination six months later revealed a slight improvement in his motor strength and reflexes but no change in sensory functions. Follow-up electromyographic evaluation demonstrated an average 89% improvement in evoked potential amplitudes and a slight improvement in distal latencies and conduction velocities. These findings suggest that the neuropathy associated with hypereosinophilia is axonal in nature and that there is a temporal relationship between reduction in the absolute eosinophil count and the improvement of the neuropathy.     

Compound nerve action potentials from the median and ulnar nerves

The compound nerve action potentials from mixed motor/sensory (MNAP) and sensory (SNAP) nerve stimulation in the median and ulnar nerves were recorded in both arms of 20 able-bodied subjects. Intranerve and internerve peak-to-peak amplitudes were compared. An SNAP/MNAP amplitude ratio greater than 0.25 exceeded the mean by 2SD. The fastest, intermediate, and slowest conduction velocities were calculated from chosen points on the biphasic waveform. An intermediate MNAP conduction velocity for the median and ulnar nerves of less than 49.5m/sec exceeded more than 2SD below the mean. Likewise, an intermediate SNAP conduction velocity of less than 45.5m/sec exceeded 2SD below the mean. Median MNAP latency across the carpal tunnel was 1.0 +/- 0.3 and ulnar MNAP conduction velocity across the elbow was 59.7 +/- 3.8m/sec. This technique may supplement traditional electrodiagnostic studies in evaluating upper extremity neuropathies.     

Cisplatin neuropathy: a prospective clinical and electrophysiological study in Chinese patients with ovarian carcinoma

Nineteen Chinese patients with stage III or IV epithelial ovarian carcinoma by the criteria established by the International Federation of Gynaecology and Obstetrics, treated with cisplatin, 120 mg/m², every 4 weeks for a maximum of twelve courses if possible, were studied prospectively with clinical and electrophysiological evaluation before and 3, 6, 9 and 12 months during cisplatin administration. Neuropathy occurred in 12 of the 19 patients at the cumulative dose of 360 mg/m². Up to 89% of the patients assessed in their final examination developed neuropathy. Decreased vibration sensation at the ankles and depressed ankle reflexes were the early manifestations. Electrophysiological findings consisted of low amplitude sensory action potentials of median, ulnar and sural nerves, and slowing of their sensory nerve conduction velocities. Despite substantial involvement of sensory nerves, there was little change in motor nerve conduction velocities or motor unit action potentials. The progression of the neuropathy was unpredictable and could be delayed. As cisplatin is highly effective in the treatment of the tumour which is invariably fatal, if inadequately treated, patient selection with regard to neurotoxicity is unnecessary.     

正常人周围神经传导速度40例分析

目的:研究健康成人周围神经运动传导速度(motor-nerveconductionve-locity,MCV)和感觉传导速度(sensory-nerveconductionvelocity,SCV)的正常值,为诊断周围神经疾病提供依据。方法:健康志愿者40例,年龄22～53岁,男女各20例。分别检测双侧正中神经、尺神经、胫神经及腓神经MCV和双侧正中神经、尺神经及胫神经SCV。分析指标包括潜伏期、波幅及神经传导速度(nerveconductionvelocity,NCV)。结果:NCV在正常人男女之间、左右侧肢体之间的差异在统计学上无显著性意义(P>0.05),并且随着年龄的增加而逐渐减慢。结论:NCV检测是周围神经病的重要诊断技术之一,而正常值的确定是临床诊断的前提。不同年龄组应采用各自的正常值。     

Standardized nerve conduction studies in the upper limb of the healthy elderly.

Nerve conduction studies are increasingly being performed on elderly individuals; however, no standardized data for the elderly population exists to provide an accurate interpretation of electrodiagnostic findings. The purpose of this study was to provide standardized data in the healthy elderly for the nerves of the upper limb that are routinely chosen for study by electromyographers. Nerve conduction studies were performed prospectively in one upper limb of 155 carefully screened healthy elderly individuals between the ages of 60 and 95 years. Upper limb temperature was controlled to limit the influence of temperature on the measured conduction parameters. Standard nerve conduction techniques using constant measured distances were applied to evaluate the median, ulnar and radial nerves. A normative electrodiagnostic database for elderly individuals was established in this study. The mean nerve conduction parameters of this healthy elderly population compared favorably with existing literature values for younger populations. However, age had a statistically significant but low strength effect on all ulnar nerve conduction velocities and distal latencies as well as the distal sensory amplitudes of all three nerves. Gender had a greater effect than age on these parameters as well as on median sensory distal latency. Other median motor and sensory conduction parameters along with radial sensory distal latency were not significantly related to age or gender based on two-way analysis of variance.     

Secondary changes in segmental neurons below a spinal cord lesion in man

The function of sensory and motor neurons below the level of a spinal cord injury (SCI) was assessed in 23 patients by recording the nerve conduction velocities and the amplitudes of evoked nerve and muscle compound action potentials for sural and posterior tibial nerves. Sensory and motor conduction velocities were generally normal when obtainable. Two patients had a unilateral reduction in the sural nerve and abductor hallucis muscle compound action potentials which may have been due to peripheral nerve compression. In 11 patients the abductor hallucis muscle compound action potential was below the normal range, while sural nerve action potentials remained within the normal range. Motor unit counts showed a reduction in the number of functioning motor units in these muscles.     

Assessment of central and peripheral nerve functions in chain-saw operators: a study of short-latency somatosensory evoked potential and peripheral nerve conduction

In order to clarify the effects of local vibration on the peripheral and central nervous system, peripheral (median) nerve conduction velocities and short-latency somatosensory evoked potentials (SSEP) following stimulation of the median nerve at the wrist were measured in 15 male forest workers in 1986. They had engaged in chain-saw operation for 16-34 (mean 22) years; their working days in 1985 averaged 124 days with a range of 50-203 days. The results indicated significant delays in maximal motor and sensory nerve conduction velocities followed by prolongation of all 4 peak latencies of SSEP up to the sensory cortex of the brain (N9, N13, N20 and P23 latencies) in chain-saw operators; their N9 and P23 latencies were significantly correlated with total working days per year. On the other hand, no significant prolongation of the interpeak latencies of SSEP (i.e., cervico-spinobulbar and central conduction times) was found in the workers. It is concluded that local vibration predominantly affects peripheral nerve conduction; cervico-spinobulbar and central nerve conduction may not be significantly affected.     

Differences in sensory conduction velocity between different sensory branches and segments of the median and ulnar nerves

Abnormality of absolute values of median sensory conduction velocities and differences in conduction velocity between median and ulnar nerves are used as criteria for abnormality in the diagnosis of carpal tunnel syndrome. Detailed studies of sensory conduction in various median and ulnar branches and segments indicate that conduction velocities measured and calculated by standard methods are different in the different nerves, segments and branches. In particular, the velocity in the middle digit branch of the median nerve is slower than that in the index, and that in the 3-4 palmar branch is slower than that in the 2-3 palmar branch. Median and ulnar sensory conduction velocities are not well correlated in the same hand in the same individual, so comparison of these nerves for diagnostic purposes is subject to some risk. Palmar and digital conduction velocity in the same nerve may not be identical and the median nerve may have asymptomatic palmar slowing of no clinical significance. The conclusion that abnormality is present must take these factors into account.     

Relationship between electroneurographic changes and serum ubiquitin levels in patients with type 2 diabetes

OBJECTIVE: The aim of the present study was to investigate any relationship between serum ubiquitin levels and electroneurographic changes in peripheral nerves for patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: The study involved 34 patients (19 men, 15 women; mean age 46 +/- 13 years) with type 2 diabetes. Serum ubiquitin values were measured by sandwich enzyme-linked immunosorbent assay Measurement of nerve conduction velocity (NCV) was performed on three motor (median, tibial, and peroneal) and three sensory (median, ulnar, and sural) nerves. The value of motor compound muscle action potential (CMAP) was obtained from the sum of median, tibial, and peroneal motor nerve amplitudes, and sensory compound nerve action potential (CNAP) was computed as the sum of median and ulnar sensory nerve amplitudes. RESULTS: Patients with diabetes were divided into three groups: group 1 (n = 8) had normal electroneurography results, group 2 (n = 8) had slowed NCV, and group 3 (n = 18) had low values of motor CMAP and/or sensory CNAP as well as slowed NCV. Mean ubiquitin level in group 3 (20.4 +/- 2.9 ng/dl) was significantly higher than that in group 1 (11.2 +/- 1.1 ng/dl, t = 11.5, P < 0.0001) and group 2 (13.2 +/- 2.7 ng/dl, t = 5.9, P < 0.0001). Serum ubiquitin levels were inversely correlated with motor CMAP (r = -0.68) and sensory CNAP (r = -0.61) values. CONCLUSIONS: The results of this study indicate that there could be a relationship between the diminished amplitudes of axons of the peripheral nerve and the increase in serum ubiquitin levels in patients with type 2 diabetes. Further studies are required to confirm this relationship.     

脑卒中后肩关节半脱位对偏瘫侧上肢周围神经电生理特征的影响

目的:探讨脑卒中后肩关节半脱位对偏瘫侧上肢周围神经电生理参数的影响。方法:纳入20例脑卒中伴肩关节半脱位的患者,分别对患者双上肢肩胛上神经、腋神经、肌皮神经、桡神经、正中神经、尺神经的运动神经传导及桡神经、正中神经、尺神经的感觉神经传导进行评估,并对偏瘫上肢冈上肌、三角肌、肱二头肌、伸指总肌、拇短展肌和小指展肌进行静息...     

New criteria for sensory nerve conduction especially useful in diagnosing carpal tunnel syndrome

This article reports a technique for determining new standard values for median sensory nerve latencies, amplitudes, and durations. Use of these values should significantly improve the ability to diagnose carpal tunnel syndrome and to reduce the number of false negative results. Forty-five median sensory nerves of 30 neurologically healthy subjects were evaluated with rigid techniques and temperature control at stimulation and recording points. Latencies for antidromic and orthodromic conduction from wrist-to-thumb, wrist-to-index finger, wrist-to-middle finger, and wrist-to-ring finger (all 14 cm distances) are reported. Conduction time for nerve impulses through the transcarpal segment via ulnar and radial nerves was also measured for comparison with median nerve latencies. In addition to latency measurements, characteristics of electrical responses evoked by stimulation were described. These include amplitude of the recorded response measured from baseline to negative peak and from negative peak to positive peak, duration of the negative response wave (from baseline to return to baseline) and duration measured from onset of the negative wave to the positive peak. According to our data, a distal median nerve sensory latency of more than 3.3 ms (the mean of 2.9 ms plus two standard deviation values of 0.18 ms) when measured to the peak of the negative wave is indicative of abnormality.     

干燥综合征伴周围神经病变的临床电生理与病理特点

目的 探究干燥综合征伴周围神经病变的临床电生理与病理特点.方法 以2018年1月至2021年1月收治的50例干燥综合征伴周围神经病变患者为试验组,同时以50例干燥综合征不伴周围神经病变患者为对照组.分析试验组临床电生理以及病理特点,比较两组患者临床表现的差异性.结果 试验组感觉神经传导异常患者中,10.00％为尺神经受...     

神经电图-肌电图检测对多灶性运动神经病的评估作用

目的:探讨神经电图(ENG)和肌电图(EMG)检查对多灶性运动神经病(multifocalmotorneuropathy,MMN)的诊断价值及康复干预的评估作用。方法:对16例诊断为MMN的患者进行电生理检查,受试者为MMN组16例和正常组16例,分别进行运动神经传导速度(MCV)和感觉神经传导速度(SCV)检查,记录刺激引出的复合肌肉动作电位(compoundmus-cleactionpotentials,CMAP)的波幅、波宽、面积、位相、时限进行对比分析,判定是否有运动神经传导阻滞(conductionblock,CB)或暂时性离散(temporaldispersion,TD)。并有选择性地进行常规肌电图检查。结果:16例患者中均见有一根以上运动神经或至少一根运动神经的一个以上部位出现CB或TD。其中13例双上肢正中神经,尺神经出现CB,3例首发为正中神经尺神经的远端出现CB,随病情进展出现下肢腓深神经CB。仅有两例感觉神经传导速度稍有减慢,波幅略有降低。16例患者神经受累区域以下所支配肌肉肌电图检查见有运动神经源性受损改变。结论:MMN病是一种以远端神经受累为主的不对称性周围神经病,神经电生理检查对诊断和鉴别诊断MMN起重要作用,CB是MMN特征性表现。     

Sensory nerve conduction velocity in children using cerebral evoked potentials

Sensory nerve conduction velocity was measured in 16 healthy volunteers from 3 to 16 years of age by using evoked cortical potentials. Using the latencies to the peaks of the 2nd and 3rd components (N1 and P2) of the average evoked response, conduction velocities for the wrist-to-elbow segment of the median nerve were found to have a range of 58 to 74 meters/second (m/s). Mean values using N1 and P2 were not significantly different. Conduction velocities in the same children obtained by stimulation of the median nerve at the elbow and wrist while recording the digital nerve action potential from the index finger had a range of 58 to 70 m/s. Mean values determined using cortical and digital potentials were not significantly different. In individual subjects, values obtained with the two techniques differed by 0 to 9 m/s using the N1 peak and 0 to 11 m/s using the P2 peak of the of the cortical potential. Reliable conduction velocity measurements for sensory nerves can be obtained in children using evoked cortical potentials with relatively simple methods. This technique has been successful when conventional methods did not detect peripheral sensory responses.     

The sensitivity of clinical diagnostic methods in the diagnosis of diabetic neuropathy

This study assessed the sensitivity of various methods for the clinical diagnosis of diabetic peripheral neuropathy. A total of 147 randomly selected patients with diabetes mellitus and 65 age- and sex-matched healthy controls were evaluated by various clinical (the neuropathy symptom score [NSS], the neuropathy disability score [NDS], vibration perception thresholds [VPTs], Tinel's sign and Phalen's sign), laboratory (fasting plasma glucose and glycosylated haemoglobin levels) and electro-physiological (nerve conduction studies, H-reflex and F-wave measurements) methods. In the patient group, 8.2% had an abnormal NSS, 28.5% had a positive Phalen's sign, 32.6% had a positive Tinel's sign, 42.8% had an abnormal VPT and 57.1% had an abnormal NDS. Significant correlations were found between electro-physiologically confirmed neuropathy and the two provocation tests and abnormal VPTs. In conclusion, assessment with a complete neurological examination and standard electrophysiological tests is very important for the diagnosis of diabetic peripheral neuropathy and the prevention of morbidity in patients with or without symptoms.     

An electrodiagnostic study in chronic alcoholic subjects

Electrodiagnostic tests were performed on 16 alcoholic subjects and 15 age-matched controls. The tests were done to determine whether nerve conduction parameters differentiate between healthy and alcoholic subjects, and if so, which of these are most useful. Significant differences between alcoholic subjects and controls were found in the following variables: median nerve motor velocity; median nerve sensory latency, amplitude and velocity; ulnar nerve motor amplitude and velocity; ulnar nerve sensory amplitude, latency and velocity; sural nerve sensory amplitude and velocity; and peroneal motor amplitude and velocity. The combination of ulnar and sural sensory conduction velocity tests identified 85% of the chronic alcoholic subjects by stepwise discriminant analysis. Tibial nerve H-reflex latencies were either absent or prolonged in 63% of the subjects. Bilateral facial nerve amplitudes and latencies were normal. The ulnar sensory amplitude and ulnar sensory velocity inversely correlated with the duration of excessive alcohol drinking.     

Ulnar nerve entrapment at the elbow localized by short segment stimulation

The purpose of the study was to evaluate the differences in the amplitudes of the compound muscle action potentials of the hypothenar muscles and the differences in conduction times. Differences in shoot segment responses were determined by stimulating the ulnar nerve at 2-cm intervals across the elbow in 20 normal adults. Thirteen ulnar nerves on the left side and 12 nerves on the right of 14 men and six women were studied for motor nerve conduction velocity. The amplitudes of the hypothenar compound muscle action potentials and the conduction times after supramaximal stimulation of the ulnar nerve were also determined. The distal-to-proximal reduction in the amplitude of the potentials was 6% on the left and 4.2% on the right. The maximum conduction time in a 2-cm segment on the right side was 0.63msec (mean +2SD = 0.43 + 0.20) and on the left, 0.60msec (mean +2SD = 0.44 + 0.16). Using the same short segment stimulation technique, ulnar nerve motor conduction was also studied in 13 patients with suspected ulnar neuropathy at the elbow in order to localize the nerve lesion. Conduction time only was abnormal in one patient, both conduction time and amplitude in nine, amplitude only in one, and conduction time and mild reduction in amplitude in two. It was concluded that short segment stimulation of the ulnar nerve at the elbow is useful in localizing the exact site of entrapment/compression of the nerve at the elbow.