Subclinical lesions of peripheral nervous system in multiple sclerosis patients

BACKGROUND AND PURPOSE: In the last years the presence of peripheral nervous system (PNS) lesions has been noted in patients with multiple sclerosis (MS). The frequency and degree of PNS damage reported by many authors differ among publications, so does the type of PNS lesions. The aim of our study was to perform an electrophysiological evaluation of the peripheral nervous system in patients with a definite diagnosis of multiple sclerosis and without any clinical signs of peripheral neuropathy. MATERIAL AND METHODS: 110 patients were included in the study, comprising 70 people with a definite diagnosis of multiple sclerosis and 40 people without any symptoms of organic nervous system lesion serving as a control group. During neurologic examination of MS patients the degree of disability measured by EDSS scale, the duration of the disease as well as number of relapses were assessed. A "disease progression factor" was calculated by dividing a number of relapses by disease duration in years. Patients with common etiologies for peripheral neuropathy such as diabetes, renal insufficiency, thyroid gland dysfunction, proliferative disorders etc. were excluded from the study. Orthodromic motor conduction and late responses (F wave) in median, ulnar, peroneal and tibial nerves as well as sensory conduction in median, ulnar (orthodromic) and sural (antidromic) nerves were evaluated. RESULTS: There was electrophysiological evidence of peripheral nervous system lesions in at least one nerve in 52 (74.2%) MS patients. In 30 patients (42.8%) more than one peripheral nerve was lesioned. There were more significant differences noted during the examination of sensory nerves. Sensory amplitudes in all of the sensory nerves examined were significantly lower than in control group. Furthermore we observed slow sensory conduction velocities and prolonged sensory latencies in ulnar and sural nerves. There were significant differences between the two groups of patients concerning motor conduction too: prolonged distal latency in tibial and sural nerves, prolonged F wave latency in median, peroneal and tibial nerves, low motor amplitude in ulnar and peroneal nerves, low motor conduction velocity in ulnar nerve -- all noted in MS patients. We found no correlation between conduction parameters and the patients' age, disease duration, number of relapses and disease progression degree. CONCLUSIONS: We found out that subclinical peripheral nervous system abnormalities are very frequent in MS patients. We noted both sensory and motor nerve lesions of a demyelinating-axonal character. Sensory abnormalities were more pronounced than motor ones. There was no correlation between the degree of PNS lesions and the patients' age and/or progression of multiple sclerosis.     

The importance of studying sural nerve conduction and late responses in the evaluation of alcoholic subjects

Motor conduction velocities of median, ulnar, peroneal, and tibial nerves and sensory conduction velocities of median and ulnar nerves were studied in 30 alcoholic subjects and a similar group of control subjects. The results were compared to sural nerve conduction velocities and late response latencies (H reflex, F response). The latter two techniques improved the diagnostic yield by 20%: Whereas 73% of our patients showed an abnormality of conduction with conventional techniques, 93% had an abnormality of sural nerve conduction, late response latencies, or both. Abnormalities of motor and sensory conduction, which were more prominent in the lower limbs than the arms, could be documented in patients who did not have any clinical evidence of peripheral neuropathy. The electrophysiologic studies performed in the present study suggest that "axonal degeneration" is the underlying pathologic process in alcoholic peripheral nerve disease.     

Peripheral neuropathy in children on long-term phenytoin therapy

Nerve conduction studies of the ulnar, median, posterior tibial, peroneal and sural nerves were performed in 21 epileptic children aged 6 to 17 years on long-term phenytoin therapy. Auditory brain stem evoked responses were obtained in 16 patients to evaluate the effect of phenytoin on central nervous system synapses. Of the 21 patients examined, 15 (71.4%) showed abnormal findings. The most frequent abnormality was slowed motor conduction velocity of the ulnar nerve (33.3%) and posterior tibial nerve (23.8%), followed by slowed sensory conduction velocity of the sural nerve (20%), lowered H/M ratio (14.3%), slowed motor conduction velocity of the peroneal nerve (14.3%) and of the median nerve (14.2%). A significant correlation was noted between the total dosage and duration of therapy with PHT and the reduction of motor conduction velocity in the posterior tibial nerve. Auditory brain stem evoked responses showed no significant differences in each peak latency between the patients and the normal control group. The study indicates that long-term phenytoin therapy can cause latent impairment of peripheral nerve function in children with no clinical evidence of peripheral neuropathy.     

Amplitude of sensory nerve action potential in early stage diabetic peripheral neuropathy： an analysis of 500 cases

Early diagnosis of diabetic peripheral neuropathy is important for the successful treatment of diabetes mellitus. In the present study, we recruited 500 diabetic patients from the Fourth Affiliated Hospital of Kunming Medical University in China from June 2008 to September 2013：221 cases showed symptoms of peripheral neuropathy （symptomatic group） and 279 cases had no symptoms of peripheral impairment （asymptomatic group）. One hundred healthy control subjects were also recruited. Nerve conduction studies revealed that distal motor latency was longer, sensory nerve conduction velocity was slower, and sensory nerve action potential and amplitude of compound muscle action potential were significantly lower in the median, ulnar, posterior tibial and common peroneal nerve in the diabetic groups compared with control subjects. Moreover, the alterations were more obvious in patients with symptoms of peripheral neuropathy. Of the 500 diabetic patients, neural conduction abnormalities were detected in 358 cases （71.6%）, among which impairment of the common peroneal nerve was most prominent. Sensory nerve abnormality was more obvious than motor nerve abnormality in the diabetic groups. The amplitude of sensory nerve action potential was the most sensitive measure of peripheral neuropathy. Our results reveal that varying degrees of nerve conduction changes are present in the early, asymptomatic stage of diabetic peripheral neuropathy.     

Peripheral neuropathy in multiple sclerosis: a clinical and electrophysiologic study

Peripheral nerve abnormalities are uncommon in multiple sclerosis (MS). When present, they are usually attributed to factors associated with advanced disease, such as malnutrition or cytotoxic drugs. We prospectively evaluated 22 mildly disabled MS patients with sensory complaints for evidence of neuropathy using the Neuropathy Symptom Score (NSS), clinical examination, and electrophysiologic studies of peripheral nerves. Distal latency, F-wave response, and nerve conduction velocity (NCV) and amplitude in the ulnar, median, tibial, peroneal and sural nerves were examined. Neuropathy was recorded if electrophysiologic abnormalities were detected in at least two peripheral nerves in the same patient. The most frequent electrophysiologic abnormalities noted were prolonged F-wave response and low motor amplitude in the peroneal nerve, slow sensory conduction velocities of the ulnar and sural nerves, and prolonged distal latencies in the sensory ulnar and sural nerves. Electrophysiologic abnormalities were found in 33 of 244 nerves examined (14.7%) and occurred in 10 patients (45.5%). Neuropathic symptoms were mild and did not correlate with electrophysiologic abnormalities. Age, disease duration, disease course and neurologic disability as evaluated by the Kurtzke Expanded Disability Status Scale, were not associated with the presence of neuropathy. Our findings indicate a high frequency of sensory-motor neuropathy in a selected group of MS patients.     

Peripheral neuropathy in genetic mitochondrial diseases

Peripheral neuropathy is an underrecognized but common occurrence in genetic mitochondrial disorders. To gain insight into the frequency and clinical presentation of this complication, nerve conduction studies were performed on 43 subjects with congenital lactic acidosis enrolled in a controlled clinical trial of oral dichloroacetate. Median and peroneal motor conduction studies and median and sural sensory conduction studies were performed on each patient. The mean amplitude of the peroneal motor nerve (P < 0.001) and the conduction velocities of the median (P < 0.001) and peroneal (P < 0.001) motor nerves were uniformly lower in our subjects than in healthy literature control subjects. There were no significant differences in sensory nerve conduction studies. A generalized reduction in motor nerve conduction velocity was the dominant electrophysiological abnormality in the patients in this study and was independent of age, sex, or congenital mitochondrial disorder. We postulate that cellular energy failure is the most likely common cause of peripheral neuropathy in patients with genetic mitochondrial diseases, owing to the high demand for adenosine triphosphate via aerobic carbohydrate metabolism by nerve tissue.     

糖尿病周围神经病电生理特点及与血糖水平的关系

目的研究糖尿病周围神经病的神经电生理特点以及与血糖水平的关系。方法分析2013年3月~2014年3月于本院神经内科住院的108例糖尿病周围神经病患者,测定其正中、尺、胫、腓总神经的运动传导速度(MCV)和复合肌肉动作电位波幅(CMAP),以及正中、尺、腓肠神经、腓浅神经的感觉传导速度(SCV)和感觉神经动作电位波幅(SNAP),比较上、下肢和运动、感觉神经异常情况,分析糖化血红蛋白(HbA1C)、餐后2 h血糖对神经传导速度(NCV)的影响。结果糖尿病患者下肢运动神经病变重于上肢,且差异明显(P<0.05)。感觉神经损害重于运动神经,且差异明显(P     

Determination of nerve conduction abnormalities in patients with impaired glucose tolerance

Recent studies have shown that impaired glucose tolerance (IGT) is associated with dysfunction in the peripheral and autonomic nerves. The aim of this study was to determine the electrophysiological abnormalities of IGT. To determine electrophysiological abnormality in the large sensorimotor and sudomotor autonomic nerves with IGT patients, 43 patients and 34 healthy subjects have been studied. Subjective neuropathy symptoms, neurological examination and the electrophysiological findings were evaluated. When conduction of large somatic fibers only was evaluated, the ratio of electrophysiological abnormality was found to be 21%. In addition, where sympathetic skin response was evaluated the sudomotor autonomic abnormality ratio was 28% in upper extremities, 53% in lower extremities, and 16% in upper and lower extremities together. The percentages of abnormal electrophysiological parameters in different motor and sensory nerves were 39.5% in the peroneal motor nerve, 20.9% in the median motor and sural sensory nerves, 18.6% in the median sensory nerve, 16.3% in the tibial motor nerve, 14% in the ulnar sensory nerve, and 2.3% in the ulnar motor nerve. While distal motor latency was the most frequent abnormal parameter in the median and tibial motor nerves, the amplitude changes in the peroneal and ulnar motor nerves were also prominent. In sensory evaluation, the onset latency in the median-ulnar sensory nerves and the amplitude in the sural sensory nerve were found to be evident abnormalities.     

Rapid genetic screening of Charcot-Marie-Tooth disease type 1A and hereditary neuropathy with liability to pressure palsies patients

We used the allele-specific PCR-double digestion method on peripheral myelin protein 22 (PMP22) to determine duplication and deletion mutations in the proband and family members of one family with Charcot-Marie-Tooth disease type 1 and one family with hereditary neuropathy with liability to pressure palsies. The proband and one subclinical family member from the Charcot-Marie-Tooth disease type 1 family had a PMP22 gene duplication; one patient from the hereditary neuropathy with liability to pressure palsies family had a PMP22 gene deletion. Electron microscopic analysis of ultrathin sections of the superficial peroneal nerve from the two probands demonstrated demyelination and myelin sheath hyperplasia, as well as an ’onion-like’ structure in the Charcot-Marie-Tooth disease type 1A patient. We observed an irregular thickened myelin sheath and ’mouse-nibbled’-like changes in the patient with hereditary neuropathy with liability to pressure palsies. In the Charcot-Marie-Tooth disease type 1A patient, nerve electrophysiological examination revealed moderate-to-severe reductions in the motor and sensory conduction velocities of the bilateral median nerve, ulnar nerve, tibial nerve, and sural nerve. Moreover, the compound muscle action potential amplitude was decreased. In the patient with hereditary neuropathy with liability to pressure palsies, the nerve conduction velocity of the bilateral tibial nerve and sural nerve was moderately reduced, and the nerve conduction velocity of the median nerve and ulnar nerve of both upper extremities was slightly reduced.     

Evaluation of atrophy of foot muscles in diabetic neuropathy -- a comparative study of nerve conduction studies and ultrasonography.

OBJECTIVE: To evaluate the relation between the findings at nerve conduction studies and the size of small foot muscles determined by ultrasonography. METHODS: In 26 diabetic patients the size of the extensor digitorum brevis muscle (EDB) and of the muscles between the first and second metatarsal bone (MIL) was determined. Motor nerve conduction studies of the peroneal and tibial nerves were performed with determination of the amplitudes of the CMAPs and of the nerve conduction velocities (NCV). Further, a standardised clinical examination was performed providing a neurological impairment score. RESULTS: Seventeen patients fulfilled the criteria for diabetic neuropathy. The cross-sectional area of the EDB muscle and the thickness of the MIL muscle were 116 +/- 65 mm2 and 29.6 +/- 8.2 mm, respectively. Close relations were established between muscle size and the amplitude of the CMAP of the peroneal (r=0.77, p<0.001) and of the tibial nerve (r=0.70, p<0.01). Further there were close relations between the muscle size and the NCV of the peroneal (r=0.62, p<0.01) and of the tibial nerve (r=0.71, p<0.001). CONCLUSIONS: The amplitude of the CMAP of the peroneal and of the tibial nerves is closely related to the size of the small foot muscles as determined by ultrasonography. SIGNIFICANCE: In diabetic patients motor nerve conduction studies can reliably determine the size of small foot muscles.     

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。     

Neurophysiological impairments in multiple sclerosis—Central and peripheral motor pathways

A systematic review of the literature was conducted comparing neurophysiological outcomes in persons with multiple sclerosis (PwMS) to healthy controls (HC), in studies of the central nervous system (CNS) function comprising motor evoked potentials (MEP) elicited by transcranial magnetic stimulation (TMS) and in studies of the peripheral nervous system (PNS) function comprising electroneuronography (ENG) outcomes elicited by peripheral nerve stimulation. Studies comparing neuromuscular function, assessed during maximal voluntary contraction (MVC) of muscle, were included if they reported muscle strength along with muscle activation by use of electromyography (EMG) and/or interpolated twitch technique (ITT). Studies investigating CNS function showed prolonged central motor conduction times, asymmetry of nerve conduction motor pathways, and prolonged latencies in PwMS when compared to HC. Resting motor threshold, amplitude, and cortical silent periods showed conflicting results. CNS findings generally correlated with disabilities. Studies of PNS function showed near significant prolongation in motor latency of the median nerve, reduced nerve conduction velocities in the tibial and peroneal nerves, and decreased compound muscle action potential amplitudes of the tibial nerve in PwMS. ENG findings did not correlate with clinical severity of disabilities. Studies of neuromuscular function showed lower voluntary muscle activation and increased central fatigue in PwMS, whereas EMG showed divergent muscle activation (ie, EMG amplitude) during MVC. When comparing the existing literature on neurophysiological motor examinations in PwMS and HC, consistent and substantial impairments of CNS function were seen in PwMS, whereas impairments of the PNS were less pronounced and inconsistent. In addition, impairments in muscle activation were observed in PwMS.     

Guillain-Barré syndrome. A clinical electrophysiological and biochemical study

Fifty-six consecutive patients with Guillain-Barré syndrome representing 49% of all cases of peripheral neuropathy (except those due to diabetes mellitus and leprosy) admitted to the Postgraduate Institute of Medical Education and Research, Chandigarh over a period of three years were studied. All patients developed weakness of limbs within one day to three weeks. Attenuation of deep tendon jerks (98%) paresthesia (66%), cranial nerve involvement (41%) and antecedent infection (32%) were the common clinical features. The common patterns of motor weakness were predominantly proximal in all the four limbs (45%) or predominantly proximal in lower limbs along with distal muscles in upper limbs (29%). Electrodiagnostic studies revealed prolonged distal (motor) latency (82%), reduced motor nerve conduction velocity (74%), sensory nerve conduction abnormality (85%) and evidence of denervation (41%). Evoked motor response of median, ulnar, common peroneal and tibial nerves exhibited significant increase in duration and reduction in amplitude. The maximum incidence of electrophysiological abnormality occurred between four to 12 weeks after the onset of neurological symptoms. Four patients died and 11 showed poor recovery. Long intervals (greater than 3 weeks) between peak deficit and onset of recovery and coexistence of reduced motor nerve conduction velocity with evidence of denervation on EMG were found to be associated with poor recovery.     

肌电图对糖尿病周围神经病的诊断价值

目的：探讨神经肌电图在糖尿病性周围神经病（DPN ）诊断中的应用价值。方法：选择我院2012年1月～2014年6月收治的200例DPN患者的临床资料,分析肌电诱发电位仪对患者的相关神经进行检测的结果。结果：在200例DPN患者中,神经电图总异常率高达71．5％。且随着病程的延长,其EM G异常率的发生逐渐增加。病程在1年以内的患者EM G异常率为40．8％,而病程在10年以上者异常率达到92．2％。病程在1年以内的患者H反射异常率为46．9％,而病程在10年以上者H反射异常率达到94％。其次是腓总神经运动传导速度（MCV）、腓浅神经感觉传导速度（SCV）异常率,分别是43．1％和58．8％,均超过40％。EM G结果提示：病程＜1年组拇短展肌、肱二头肌、胫前肌、趾总伸肌EM G异常率均为0,病程≥10年组异常率分别为17．6％、9．8％、21．5％、31．4％,同样随病程延长而异常率增加。结论：EM G在诊断DPN中具有较高的准确性,有利于早期发现和进行治疗。     

多发性硬化周围神经损害的肌电图及病理研究

目的：探讨多发性硬化（MS）产生周围神经损害的肌电图，病理特点和影响MS累及周围神经的相关因素。方法：33例MS患者，均满足Poser的确定诊断标准，排除其他神经系统疾病，30名正常自愿受试者作为对照，排除周围神经损害的相关因素，两组分别进行运动，感觉神经传导检测，F波潜伏期及出现率，H反射潜伏期检测，腓肠神经活检，光镜及电镜观察周围神经病理变化。结果：（1）33例MS患者中，9例有根性疼痛，3例有手袜套样感觉障碍，6例不对称性肌萎缩，2例有明显的自主神经症状；（2）肌电图显示复合肌肉动作电位波幅降低，正中神经，尺神经感觉运作电位波幅增高，F波及H反射的潜伏期延长，F波出现率降低。MS周围神经损害的程度与神经功能缺损、病程及病变部位有关，神经功能缺损越重，病程越长，胫神经和腓总神经运动传导波幅降低越明显，正中神经、尺神经感觉动作电位波幅增高越明显；脊髓型MS周围神经受损明显高于脑型；（3）6例患者腓肠神经活检，光镜下可见有髓纤维呈不同程度的髓鞘脱失。电镜下以轴索变性为主，髓鞘板层解离及髓球形成。结论：MS是一种以CNS受损为主的脱髓鞘疾病，在部分患者可对同时累及周围神经系统，脱髓鞘改变主要发生在脊神经根，远端轴突可继发轴索损害，肌电图是比较理想的可全面评价MS周围神经损害的临床检测手段，对判断预后有一定的实用价值。     

Painful Diabetic Neuropathy - A Therapeutic Challenge For The New Millennium

Clinical spectrum of diabetic neuropathy is variable; it may be asymptomatic, but once established, it becomes irreversible and disabling. Some investigators suggested that earliest change in diabetic nerve function is alteration in axonal excitability due to alterations in ion conductance of axon membrane, although these functional changes of ion channels necessarily cause permanent damage or degeneration of nerve fibers. Among various parameter of nerve conduction study in diabetics, prolonged F-wave latency in the peroneal and tibial nerve seems the commonest abnormality in asymptomatic patients. Decrease in amplitude of compound sensory action potential of sural nerve is another earlier abnormality, which is, then, accompanied by a fall in motor amplitude of peroneal and tibial nerves in advanced patients. In disabled patients no motor response is often elicited in the legs. Previous electrophysiological studies could not make clear if central axons were involved or not in diabetic neuropathy. Recently, our group has demonstrated that somatosensory central conduction from the spinal cord to the sensory cortex is delayed in diabetics as well as in the peripheral conduction, which might be partly responsible for the irreversible clinical presentation of diabetic neuropathy.     

标准化F波潜伏期对糖尿病周围神经病的诊断价值

目的 探讨标准化F波潜伏期在糖尿病周围神经病(DPN)中的诊断价值.方法 采用前瞻性研究方法 ,收集神经传导检查正常的DPN患者48例,另选择年龄和性别匹配的健康自愿者48名为对照组.采用肌电图诱发电位仪检测两组正中神经、尺神经、胫神经及腓总神经F波最短潜伏期(FLmin)、F波平均潜伏期(FLmean)、F波潜伏最长...     

Late sequelae of recurrent occupational lead poisoning--the status of the nervous system

In 44 men with a history of repeated occupational lead poisoning multidisciplinary clinical and laboratory investigations were carried out. The number of lead poisoning episodes was from 2 to 7. Apart from peripheral hypalgesia on the extremities (in 6 cases) no other neurological abnormalities were found. The motor nerve conduction velocity in the median, ulnar, radial, peroneal and tibial nerves was slightly slower in 27 cases and considerably slower in one case. Slowed down conduction velocity was most often observed in 2 nerves (12 cases) and in one nerve (9 cases), less frequently in three (4 cases) and four (2 cases) nerves. In one case this slowing down was found in all five studied nerves. Conduction changes were found in 21 peroneal nerves, 15 ulnar nerves, 12 median nerves, 7 tibial nerves and 2 radial nerves. The authors think that for the evaluation of the condition of the peripheral neuron in cases of past lead poisoning it would be sufficient to determine the conduction velocity in the ulnar and peroneal nerves. Plumbism neuropathy have the character of subclinical lesions not impairing motor skill.     

Electrophysiological findings in immune checkpoint inhibitor-related peripheral neuropathy

ObjectiveTo report the electrodiagnostic features of immune checkpoint inhibitor (ICI)-related neuropathy.MethodsWe retrospectively reviewed clinical presentations and electrodiagnostic features of 23 patients studied after receiving immune checkpoint inhibitors (ICIs). The presentations for electrodiagnostic evaluation included an acute neuropathy or neuromuscular junction disorder. We applied established electrodiagnostic criteria for polyneuropathy and acute demyelinating neuropathy.ResultsWe identified acute demyelinating neuropathy (13 cases), axonal sensory motor neuropathy (5), pure sensory neuropathy (4) and mononeuropathy (1). 13 patients had acute demyelinating neuropathy confirmed by demonstrating demyelination in 2 or more nerves; 3 additional patients had demyelination in only one nerve. Analysis of motor nerve conduction parameters revealed demyelination involving median and ulnar nerve distal motor latencies as well as median, ulnar and peroneal nerve conduction velocities. Conduction block was found in median, ulnar and peroneal nerves. The remaining one-third patients without demyelination had acute painful axonal neuropathy. Coexisting myopathic changes (6) and neuromuscular junction dysfunction (4) were also identified.ConclusionsOur findings suggest that, while immune-mediated motor nerve demyelination is the primary underlying mechanism of ICI-related neuropathy, axonal painful neuropathy can also be an important presentation. Early recognition and effective intervention may reduce morbidity and permanent disability.SignificanceElectrophysiological studies might be useful in the evaluation of ICI-related neuropathy.     

The application of F wave measurements in hepatic patients

The ulnar and tibial nerve F response latencies were analyzed to study the proximal motor conduction velocity in 15 patients with liver disease. The results were compared with those obtained from 15 normal subjects. The tibial MNCV (P less than 0.01) and FWCV from spinal cord to elbow and knee for ulnar and tibial nerves (P less than 0.001) were significantly reduced in patients compared to the controls. Minimum, mean and maximum F latencies showed significant differences for ulnar (P less than 0.001) and tibial (P less than 0.01) nerves in patients with respect to the controls. The mean F determination compared to the minimum F and delta F did not improve disease identification. The conduction abnormality in hepatic patients appeared to be present only in the proximal segment of the ulnar nerve, whereas it was more uniformly distributed along the entire length of the tibial nerve. This demonstrates that the peripheral nerve involvement in hepatic disease is more diffusely present than can be determined by conventional conduction study only.