F-waves persistence in peripheral sensory syndromes / Persistência das ondas-F nas síndromes sensitivas periféricas

Abstract Background The distinction between sensory neuronopathies (SN), which is by definition purely sensory, and sensory polyneuropathies (SP) and sensory multineuropathies (SM) is important for etiologic investigation and prognosis estimation. However, this task is often challenging in clinical practice. We hypothesize that F-wave assessment might be helpful, since it is able to detect subtle signs of motor involvement, which are found in SP and SM, but not in SN. Objective The aim of the present study was to determine whether F-waves are useful to distinguish SN from SP and SM. Methods We selected 21 patients with SP (12 diabetes mellitus, 4 transthyretin familial amyloid polyneuropathy, 4 others), 22 with SM (22 leprosy), and 26 with SN (13 immune-mediated, 10 idiopathic, 3 others) according to clinical-electrophysiological-etiological criteria. For every subject, we collected data on height and performed 20 supramaximal distal stimuli in median, ulnar, peroneal, and tibial nerves, bilaterally, to record F-waves. Latencies (minimum and mean) and persistences were compared across groups using the Kruskal-Wallis and Bonferroni tests. P-values < 0.05 were considered significant. Results All groups were age, gender, and height-matched. Overall, there were no significant between-group differences regarding F-wave latencies. In contrast, F-wave persistence was able to stratify the groups. Peroneal F-wave persistence was higher, bilaterally, in the SN group compared to SM and SP (p < 0.05). In addition, F-waves persistence of the ulnar and tibial nerves was also helpful to separate SN from SP (p < 0.05). Conclusion F-wave persistence of the peroneal nerves might be an additional and useful diagnostic tool to differentiate peripheral sensory syndromes.

Resumo Antecedentes A distinção entre neuronopatias sensitivas (SN) e polineuropatias sensitivas (SP) e multineuropatias sensitivas (SM) é importante para a investigação etiológica e para o prognóstico. Contudo, esta tarefa é desafiadora na prática clínica. Hipotetizou-se que a avaliação das ondas-F pode ser útil, por ser capaz de detectar envolvimento motor nas SP e SM, mas não nas SN. Objetivo Determinar se as ondas-F podem ajudar a distinguir entre SN, SP e SM. Métodos Selecionou-se 21 pacientes com SP (12 diabetes mellitus, 4 ATTR-FAP e 4 com outras neuropatias), 22 com SM (22 hanseníases) e 26 com SN (13 imunomediadas, 10 idiopáticas e 3 com outras neuronopatias), de acordo com critérios clínicos, etiológicos e eletrofisiológicos. Para cada indivíduo, foi aferida a altura e foram aplicados 20 estímulos distais supramáximos nos nervos mediano, ulnar, fibular e tibial, bilateralmente, para registrar as ondas-F. Uma comparação foi feita, por grupo, das latências (mínimas e médias) e persistências pelos testes Kruskal-Wallis e Bonferroni. Valores de p < 0.05 foram considerados estatisticamente significativos. Resultados Todos os grupos foram pareados por idade, sexo e altura. Não houve diferença estatística significativa entre os grupos quanto às latências das ondas-F. A persistência da onda-F foi capaz de estratificar os grupos, sendo as dos nervos fibulares bilateralmente maiores no grupo SN que nos grupos SM e SP (p < 0.05). Adicionalmente, a persistência das ondas-F dos nervos ulnares e tibiais também foi útil para distinguir SN de SP (p < 0.05). Conclusão A persistência das ondas-F dos nervos fibulares pode ser uma ferramenta adicional e útil para diferenciar síndromes sensitivas periféricas.

Sural nerve conduction: Amplitude and distal latency of sensory nerve action potential

Background: The sensory nerve action potential (SNAP) is an important factor in the electro diagnostic evaluation of a patient with suspected peripheral neuropathy. Sural nerve is the most frequently studied nerve in the electrophysiology. For proper diagnosis sural sensory conduction abnormalities, a reference data are required for each electrophysiology laboratory. Aims and Objectives: The aim of the study was to find out normative reference data of amplitude and distal latency (DL) of sural SNAP for Northern Kerala population. Materials and Methods: The study was designed as cross-sectional and observational study and analysis of values was done using SPSS version 16. A total of 250 healthy subjects of age 15–50 from Northern Kerala participated in the study which included equal number of males and females. Results: Normative reference data for sensory amplitude and DL were derived in the present study. Sensory amplitude was more and DL was found to be less in female population, indicating faster nerve conduction in female. Conclusion: The reference data derived here can be utilized to detect any abnormality sural nerve sensory conduction. The gender effect on sural nerve sensory conduction parameters can be attributed to the height difference, as nerve conduction velocity is inversely proportional to height.

Nerve Conduction Studies in Asymptomatic HIV Positive Persons

Background: Nerve Conduction Studies were performed in asymptomatic HIV positive persons and corresponding controls to detect subclinical peripheral nervous system involvement in early stage of HIV. Aims & Objective: To perform Nerve Conduction Studies in asymptomatic HIV positive persons and corresponding controls. Material and Methods: In this study,100 participants in the age group 25-45 years were selected. In study group, 50 3 participants who were HIV positive and asymptomatic (CD4 count > 350 cells/mm ) and were not on Anti Retro Viral Treatment (ART), were included. In control group 50 healthy age matched HIV negative participants were included. We performed Nerve Conduction Studies in these participants. For motor nerves, Distal Latency (DL), Motor Nerve Conduction Velocity (MNCV), Compound Muscle Action Potential (CMAP) amplitude were measured and for sensory nerves Onset Latency (OL), Sensory Nerve Conduction Velocity (SNCV) and Sensory Nerve Action Potential (SNAP) amplitude were measured. Results: Nerve Conduction Studies in asymptomatic HIV revealed that, MNCV was significantly decreased for median motor nerve and tibial motor nerve in study group compared to control group, SNAP was significantly reduced for median sensory nerve in study group compared to control group, OL was significantly prolonged for sural nerve in study group than control group and SNCV was significantly decreased for sural nerve in study group than control group. Conclusion: Nerve Conduction Studies in asymptomatic HIV positive persons suggests subclinical peripheral nervous system involvement in early stages of HIV. Hence Nerve Conduction Studies can be important to detect subclinical peripheral nervous system involvement in the early stages of HIV.

Study on electrophysiological changes of peripheral nerves in type 2 diabetes mellitus

Background: Peripheral neuropathy is a common and disabling complication due to diabetes mellitus. In such neuropathy, the function of sensory neurons, motor neurons, and autonomic functions are affected. The involvement of sensory function predominates in majority of cases. The neuropathy when develops is not reversible and also can not be stopped with any modality of treatment. Aim and Objectives: The objective is to evaluate diabetic neuropathy using the electrodiagnostic studies which are considered as a valuable tool. These studies are sensitive, specific, reproducible, and easily standardized. Material and Methods: Forty patients were subjected to electrodiagnostic study to evaluate the status of peripheral nerves in type- 2 diabetic patients. The different conduction velocities (motor nerve conduction velocity [MNCV], sensory nerve conduction velocity [SNCV]), distal latency (DL), nerve action potential (sensory nerve action potential [SNAP], and combined muscle action potential [CMAP]) are studied. All the cases were divided into two groups based on normal and abnormal diabetic neuropathy score. Sex, body mass index matched thirty numbers of healthy adults of both sexes were included in the control group. Nerve conduction study (NCS) of all the three groups were compared. Result: Neuropathy mostly peripheral was observed in 15 (37.5%) cases. The age of majority of cases was from 50–60 (45%) with mean age of 52.42 ± 7.39, having predominance of male (66.67%) in cases with symptoms of neuropathy. Fourteen (93.33%) cases out of the above cases had abnormal NCS. Abnormal NCS was also found in cases without clinical neuropathy, i.e. 14 (56%). The mean values of CMAP, SNAP, MNCV, and SNCV with prolonged DL are observed which was statistically significant. The conduction defect was observed more in lower limbs than in upper limbs. In the category of the motor nerve (common peroneal) is the most affected whereas the most affected sensory nerve was Sural nerve. Conclusion: Affection of nerves with neuropathies due to diabetes was in Sensory nerve than motor nerve. Early screening for neuropathy in clinical practice with NCSs can help in early diagnosis and their management.

Utilization of Nerve Conduction Study for the Detection of Diabetic Polyneuropathy in a Tertiary Care Center in Madhya Pradesh

Introduction: Diabetes mellitus is a group of metabolic disorders that share the phenotype of hyperglycemia. The clinical and economic burden of diabetic polyneuropathy (DPN) stems from its central role in the pathophysiology of foot ulceration and lower limb amputation, reduction in quality of life. Simple screening methods are of limited value in early neuropathy. Nerve conduction studies (NCSs) are the most sensitive and specific DPN detection method. Material and Method: This study was conducted to detect the sensory-motor neuropathy in type 2 diabetes mellitus by clinical examination and nerve conduction study. In this study, 50 cases of type 2 diabetes were taken. Results: Majority of patients presented with tingling sensation and followed by burning feet. In 50 patients of type 2 diabetes mellitus on clinical examination, most of the patients had involvement of both upper and lower limbs followed by only lower limb involvement, whereas on NCS, there were more patients with both upper and lower limbs involvement as compared to clinical studies. Maximum patients had symmetrical limb involvement clinically, but on NCS, the number of patients with symmetrical limb involvement was even more. Conclusion: It was found that patients with diabetes mellitus, diabetic peripheral neuropathy is highly prevalent, but in the majority of patients, it is subclinical. Sensitivity and negative predictive values of the neurological examination are low. Therefore, routine nerve conduction velocity measurement for the assessment of diabetic peripheral neuropathy appears to be warranted in these patients. Thus, the author concluded in this study, detection of neuropathy is earlier and significant with NCS compared to clinical.

Reliability of diabetic neuropathy symptom and diabetic neuropathy examination scoring system for the diagnosis of diabetic peripheral neuropathy in type 2 diabetes mellitus patients

Background: This study aims to evaluate the reliability of the Diabetic Neuropathy Examination Score (DNE), 10-g Semmes-Weinstein Monofilament Examination and Quantitative Sensory Testing by Vibration Perception Threshold (VPT) in the diagnosis of diabetic polyneuropathy and seek a cost effective and reliable screening method in diabetic OPD and IPD against the gold standard of NCV.Methods: This study was carried out in 50 confirmed type 2 diabetic patients matched for age, sex, duration and ABI >0.9 irrespective of the presenting complaints. Patients with either limb amputation, other reasons for peripheral neuropathy, ABI <0.9, critical and comatose were excluded. A complete neurological assessment using a symptom questionnaire, Semmes Weinstein monofilament, vibration and thermal threshold perception analyzer was done and recorded. A score was given out of 20. The patients were retrograde subjected to NCV by a blinded technician and the readings were then compared to the scores.Results: The level of significance between the total neuropathy score and the presence of neuropathy (by NCV) was very significant (p<0.0001) with an association of 0.932. In patients with a mean total neuropathy score of 3.28,10.80 and 15.37, there was no, mild and severe levels of neuropathy in NCV respectively.Conclusions: There is correlation between the total neurological scores and NCV. Therefore, it can be used to screen all diabetic patients for earliest signs of diabetic neuropathy with sustainable results.

Potencial de ação duplo e alterações ecográficas do nervo mediano em doentes com síndrome do túnel cárpico / Double peak action potential and ultrasonography nerve evaluation in patients with carpal tunnel syndrome

Introdução: A síndrome do túnel cárpico (STC) é sustentada pela presença de lentificação do potencial de ação do nervo mediano no estudo ortodrómico de condução nervosa sensitiva em comparação com o nervo radial (EC-MR). Uma técnica modificada de registo simultâneo de ambos os nervos (EC-MRsimul) pode ser utilizada, detetando a lentificação do nervo mediano através da presença de potencial de ação sensitivo duplo (PAS-D). O objetivo deste estudo é correlacionar o PAS-D com os achados de EC-MR e com o edema perineural em doentes com diagnóstico de STC. Métodos: Indivíduos saudáveis e doentes com STC há menos de 12 meses foram submetidos a avaliação eletrofisiológica, incluindo o EC-MR e o EC-MRsimul. Foi também realizada ultrassonografia para registo da área seccional do nervo mediano (AS-NM) no punho e antebraço e, respetivo índice punho-antebraço (I-PA). Resultados: Foram recrutados 38 doentes com idade média de 54,8 ± 15,3 anos com STC e 18 indivíduos saudáveis. A diferença de latência distal entre o nervo mediano e radial foi superior nos doentes (0,80 ± 0,30ms vs. 0,15 ± 0,20ms; p=0,015). O EC­MRsimul demonstrou a presença de PAS-D nos indivíduos sintomáticos. A AS­NM no punho foi também superior nos doentes (8,9 ± 0,9mm2 vs. 6,6 ± 0,7mm2; p<0.003), tendo sido identificado um quisto sinovial e um neurinoma. O edema perineural traduzido pela AS-SM correlacionou-se positivamente com a diferença de latência interpico no EC-MR e com a presença de PAS-D. Conclusão: O PAS-D está associado à presença de lentificação da condução e ao edema perineural do nervo mediano no contexto de STC ou devido a lesões ocupantes de espaço. (AU)

Introduction: Carpal tunnel syndrome (CTS) is characterized by median nerve action potential slowing, which can be shown in comparative orthodromic sensory nerve conduction studies between median and radial nerve (NCS-MR). A modified technique with simultaneous recording of both nerves (NCS-MRsimul) can also be used to detect median nerve slowing through the presence of double peak action potential (DPp). The study aims to correlate the presence of DPp with NCS-MR findings and with perineural edema in patients diagnosed with STC. Methods: Healthy individuals and patients with CTS for less than 12 months underwent NCS-MR and MRsimul. An ultrasonography evaluation was also performed to record the medial nerve sectional area (SA-MN) on the wrist and forearm, and the wrist-to-forearm ratio (WFR) was calculated. Results: We recruited 38 patients with CTS whose mean age was 54.8 ± 15.3 years and 18 healthy individuals. Distal latency difference between the median and radial nerves was higher in patients with CTS (0.80 ± 0.30 ms vs. 0.15 ± 0.20 ms, p = 0.015). NCS-MRsimul showed DPp in symptomatic individuals. SA-MN in the wrist was also higher in patients with CTS (8.9 ± 0.9 mm2 vs. 6.6 ± 0.7 mm2 , p <0.003). Ultrasonography evaluation identified a synovial cyst and a neurinoma. Perineural edema traduced by higher SA-MN and WFR correlated positively with interpeak latency difference in NCS-MR and with the presence of DPp. Conclusions: DPp was associated with median nerve sensory action potential slowing and with perineural edema due to either CTS or to space-occupying lesions. (AU)

Study of clinical and nerve conduction study correlation in patients of diabetic neuropathy in diabetes mellitus type 2

Background: Diabetes mellitus (DM) is a metabolic disorder characterized by chronic hyperglycemia with disturbance of carbohydrate, fat, and protein metabolism resulting from defects in insulin secretion, insulin action or both with an increased risk of neuropathy. Early diagnosis and management of diabetic polyneuropathy (DPN) are crucial as failure to diagnose can lead to serious consequences, including disability and amputation. Present study aimed at investigating the demographic profile and correlation of clinical features with nerve conduction studies in patients with diabetic neuropathy in type 2 diabetes mellitus.Methods: The cross-sectional study design with total 66 patients of type 2 DM were selected in 30 to 60-year age groups, from Pt. Jawaharlal Nehru Memorial Medical College, Department of Medicine, Raipur (C.G.) (Pt. JNMMC) and associated hospital. Descriptive statistics and χ2 test were used for analysing the data.Results: Total 66 patients were selected, Most of the patients are presenting with tingling sensation (n=64, 97.0%) and burning feet (n=52, 78.8%), NCV is mostly absent in the tibial nerve (n=52, 78%), sural nerve (n=63, 95.5%) and planter nerve (n=41, 62.1%) while it is largely normal in median nerve (n=54, 81.8%) and ulner nerve (n=61, 92.4%). Tingling sensation, burning feet, diminished vibration sensation and diminished light touch are significantly associated (p=0.00) with NCV in different nerves.Conclusions: Limitations of study includes small sample size, lack of general population, and a control group. Diabetes mellitus is a chronic illness with an increased risk of neuropathy. NCS having high sensitivity and specificity for detection of DPN. Understanding the NCS and its correlates in patients with DPN is crucial for early detection and development of effective management and strategies to prevent its complications.

Long-Term Rehabilitation for Intensive Care Unit-acquired Weakness with Orthostatic Hypotension Following Severe Pneumonia：A Case Report / The Japanese Journal of Rehabilitation Medicine

A 66-year-old man was admitted to our intensive care unit because of severe pneumonia. He was treated with mechanical ventilation, antibiotics, and corticosteroids, but muscle weakness developed rapidly. His muscle strength declined to a Medical Research Council scale sum score of 18/60；thus, a diagnosis of intensive care unit-acquired weakness (ICU-AW) was made. The results of nerve conduction studies were compatible with critical illness polyneuropathy. Mechanical ventilation was required for 95 days because of continuous respiratory failure. Rehabilitation began at 48 hours after hospitalization and was continued to prevent immobilization even when he was mechanically ventilated. However, orthostatic hypotension developed and inhibited mobility training. Physical and occupational therapies provided muscle strengthening exercises followed by a progressive mobility program that assisted him to raise his head, sit on the edge of the bed, and stand up. The intervention was performed within safety criteria of vital signs and the rating of perceived exertion (RPE) Borg scale between 11 and 13. It resulted in the attenuation of orthostatic hypotension and the recovery of muscle strength. He finally achieved independence in activities of daily living and the ability to walk without help after 271 days of admission. This case report suggests that long-term rehabilitation within safety criteria of vital signs and RPE Borg scale between 11 and 13 is safe and feasible without overuse weakness for ICU-AW with orthostatic hypotension.

Reference values for nerve conduction studies in healthy newborns, infants and children in Philippine Children's Medical Center

@#<p style="text-align: justify;"><strong>BACKGROUND:</strong> Nerve conduction studies play a diagnostic role in the clinical evaluation of neuromuscular disorders in children. Reference ranges define the expected parameter values in disease-free children.</p><p style="text-align: justify;"><strong>OBJECTIVE:</strong> To propose reference values for sensory and motor nerve conduction and late responses in upper and lower limb peripheral nerves in Filipino children 5 years and below.</p><p style="text-align: justify;"><strong>METHODS</strong>: Sensory nerve conduction studies on median, ulnar, superficial peroneal, and sural nerves and motor nerve conduction and late response studies on median, ulnar, peroneal and posterior tribal nerves were done using standardized techniques among 100 healthy Filipino children.</p><p style="text-align: justify;"><strong>RESULTS:</strong> Subjects were stratified according to age groups. Reference values for the following parameters: (1) sensory conduction velocity and amplitude; (2) motor conduction velocity, amplitude and latency at distal sites;  (3) F-wave latency; and (4) H-reflex latency were summarized. These were expressed as mean ±standard deviation or median (range) for values that follow Gaussian and non-Gaussian distributions. The 5th and 95th percentile values were likewise reported. Age had direct correlation with various nerve conduction parameters. Height was directly correlated with F-wave parameters of median, ulnar and peroneal nerves but not posterior tribal nerve.</p><p style="text-align: justify;"><strong>CONCLUSIONS</strong>: Reference standards for nerve conduction studies of commonly tested nerves of Filipino children are presented. Values are comparable to reference ranges elsewhere except for the H-reflex latency which is higher in this study.</p>

Analysis of the clinical and electrophysiological characteristics of multifocal motor neuropathy / 中华内科杂志

Ten patients diagnosed with multifocal motor neuropathy ( MMN) were recruited in the Department of Neurology at Chinese PLA General Hospital from January 1, 2009 to August 31, 2015.The clinical and electrophysiological features were analyzed retrospectively .All patients complained of progressive asymmetric limb weakness , which was more severe in distal than in proximal . Five presented muscle atrophy.None had sensory disturbances .All suffered diminished or disappeared tendon reflex , whereas Babinski signs were negative .Multi-focal conduction block ( CB) was confirmed by nerve conduction studies ( NCS) in all patients and 7 showed spontaneous potentials in needle electrode electromyography .Abnormal sensory nerve conduction was seen in 3 patients.Laboratory test revealed anti-ganglioside GM1 antibody in cerebrospinal fluid (CSF) in 6 cases and elevated CSF protein in 7 cases.Limb weakness alleviated greatly in 9 cases after intravenous immunoglobulin ( IVIg) treatment.But the other one reported poor response , who had long course of disease , serious limb weakness and obvious muscle atrophy .Motor nerve damage is the most important manifestation of MMN and sensory nerve damage may also appear .NCS is essential to the diagnosis of this disease , with CB as the characteristic electrophysiological feature .IVIg is an effective treatment.

Guillain-Barre Syndrome Presenting with Hyperreflexia – A Rare Case Report.

Guillian-Barre syndrome (GBS) is an acquired autoimmune polyradiculopathy. Areflexia and progressive flaccid weakness are essential for its diagnosis. Here we report a case of 25 year old female presenting with acute onset flaccid quadriparesis. The diagnosis of GBS was made on history and clinical findings supported by cerebro-spinal fluid (CSF) analysis and nerve conduction studies (NCS). The hallmark of this case was the presence of hyperreflexia in all four limbs without involvement of higher functions, sensory, autonomic and bulbar dysfunction. To diagnose this rare entity, a high index of suspicion is needed.

Diagnostic Significance of Ultrasonographic Measurements and Median-Ulnar Ratio in Carpal Tunnel Syndrome: Correlation with Nerve Conduction Studies

BACKGROUND AND PURPOSE: We determined the reliability of ultrasonography (US) measurements for diagnosing carpal tunnel syndrome (CTS) and their correlation with symptom duration and electrophysiology findings. We determined whether the ratio of the median-to-ulnar cross-sectional areas (CSAs) can support CTS diagnoses. METHODS: The pisiform CSA (CSA(pisiform)), swelling ratio (SR), palmar bowing, and CSA(pisiform)/ulnar CSA (CSA(ulnar)) measurements made in two subgroups of CTS patients (having sensory affection alone or having both sensory and motor affection) were compared with controls. CSA(ulnar) was measured in Guyon's canal at the level of most-protuberant portion of the pisiform bone. RESULTS: The values of all of the measured US parameters were higher in patients with CTS (n=50) than in controls (n=62). CSA(pisiform) could be used to diagnose CTS of mild severity. All of the parameters were positively correlated with the distal latency of the compound muscle action potential, and all of them except for SR were negatively correlated with the sensory nerve conduction velocity. A CSA(pisiform)/CSA(ulnar) ratio of ≥1.79 had a sensitivity of 70% and a specificity of 76% for diagnosing CTS. CONCLUSIONS: Only CSA(pisiform) measurements were reliable for diagnosing early stages of CTS, and CSA(pisiform)/CSA(ulnar) had a lower diagnostic value for diagnosing CTS.

Diagnostic Significance of Ultrasonographic Measurements and Median-Ulnar Ratio in Carpal Tunnel Syndrome: Correlation with Nerve Conduction Studies

BACKGROUND AND PURPOSE: We determined the reliability of ultrasonography (US) measurements for diagnosing carpal tunnel syndrome (CTS) and their correlation with symptom duration and electrophysiology findings. We determined whether the ratio of the median-to-ulnar cross-sectional areas (CSAs) can support CTS diagnoses. METHODS: The pisiform CSA (CSA(pisiform)), swelling ratio (SR), palmar bowing, and CSA(pisiform)/ulnar CSA (CSA(ulnar)) measurements made in two subgroups of CTS patients (having sensory affection alone or having both sensory and motor affection) were compared with controls. CSA(ulnar) was measured in Guyon's canal at the level of most-protuberant portion of the pisiform bone. RESULTS: The values of all of the measured US parameters were higher in patients with CTS (n=50) than in controls (n=62). CSA(pisiform) could be used to diagnose CTS of mild severity. All of the parameters were positively correlated with the distal latency of the compound muscle action potential, and all of them except for SR were negatively correlated with the sensory nerve conduction velocity. A CSA(pisiform)/CSA(ulnar) ratio of ≥1.79 had a sensitivity of 70% and a specificity of 76% for diagnosing CTS. CONCLUSIONS: Only CSA(pisiform) measurements were reliable for diagnosing early stages of CTS, and CSA(pisiform)/CSA(ulnar) had a lower diagnostic value for diagnosing CTS.

A family with Charcot-Marie-Tooth disease (type 1): evaluating diagnostic role of nerve conduction studies.

We aimed to report a case history of a family with Charcot-Marie-Tooth disease and to assess the role of nerve conduction studies in the diagnosis. A 10-year-old girl presented with difficulty in walking with a history of delayed motor milestones and slowly progressive weakness in distal muscles of both the lower limbs, with similar group of complaints in her father and a younger brother. Clinical examination of the patients was done and nerve conduction studies were performed. Clinical features and nerve conduction studies suggested the diagnosis as Charcot-Marie-Tooth disease with characteristic electro-diagnostic findings of Charcot-Marie-Tooth disease type-1. Charcot-Marie-Tooth disease is a rare disorder found in India. Although genetic tests form the basis of accurate diagnosis, yet nerve conduction studies, to a great extent, prove to be remarkable in approaching the diagnosis and distinguishing the common subtypes of this rare condition.

Application values of electromyography in diagnosis and differential diagnosis of diabetic polyneuropathy and alcoholic peripheral neuropathy / 吉林大学学报(医学版)

Objective To study the features and differences of electromyography of diabetic polyneuropathy (DPN) and alcoholic peripheral neuropathy (APN ), and to provide reference basis for the clinical application of electromyography.Methods 58 patients with DPN and 30 patients with APN were used as subjects. Nerve conduction studies (NCS)and sympathetic skin response (SSR)were performed in the patients, all data were analyzed.Results In the patients with DPN, the abnormalities of NCS and SSR were increased with the prolongation of the time diabetes,and the abnormality of SSR was higher than that of NCS(P<0.05).In the patients with APN, both demyelination and axonal loss in motor and sensory nerves were significantly involved, and the abnomalities of NCS and SSR were higher than those of the DPN patients (P<0.05 or P<0.01);but the proximal nerves were just involoved mildly. Conclusion Both DPN and APN have characteristic electrophysiological features.Early electromyography is useful for the early diagnosis of DPN and APN.According to the electrophysiological features of DPN and APN,the reason of peripheral neuropathy in the patients who have diabetes mellitus and alcoholism could be differentiated.

The Effects of Working Hours on Nerve Conduction Test in Computer Operators

Background: Long hours of work at a computer can result in potential adverse effects such as pain, paraesthesia, and subjective weakness of upper extremities with associated decreased nerve conduction velocities of peripheral nerves (median and ulnar). Objective: To determine whether repetitive tasks performed for long hours by computer operators can lead to peripheral neuropathy as measured by nerve conduction studies of upper extremities. Material And Methods: We performed nerve conduction tests on 50 computer operators in two study groups. Group I consisted of computer operators who worked a minimum of 6 hours per day at the computer while Group II worked a maximum of 2 hours per day. Results: Significant differences were observed between groups for most physical signs. In addition, there were significant differences between the groups for nerve conduction velocities of the medial (motor & sensory) and ulnar (motor & sensory) nerves. Conclusion: We found symptoms of pain, paraesthesia and subjective weaknesses as well as decreased conduction velocities of peripheral nerves in computer operators who work long hours. Further nerve conduction studies are needed to confirm predictive value for the development of carpal tunnel syndrome.

Carpal tunnel syndrome in the elderly: nerve conduction parameters / Síndrome do túnel do carpo em idosos: parâmetros de condução nervosa

Objective: To establish nerve conduction parameters for carpal tunnel syndrome (CTS) electrodiagnosis in the elderly. Method: Thirty healthy subjects (65-86 years), 9 male and 21 female, were studied. Routine median and ulnar sensory and motor nerve conduction studies, median mixed palmar latency, comparative latency techniques median to ulnar (sensory, mixed and motor lumbrical-interossei), median to radial (sensory), and combined sensory index (CSI) were performed in both hands. Results: The upper limits of normality (97.5 percent) were: median sensory distal latency 3.80 ms (14 cm); median motor distal latency 4.30 ms (8 cm); median palmar latency 2.45 ms (8 cm); lumbrical-interossei latency difference 0.60 ms (8 cm); comparative median to radial 0.95 ms (10 cm); comparative median to ulnar 0.95 ms (14 cm); comparative palmar median to ulnar 0.50 ms (8 cm); and CSI 2.20 ms. Sensory and mixed latencies were measured at peak. Conclusion: Our results establish new nerve conduction parameters for mild CTS electrodiagnosis in the elderly and will be helpful to reduce the number of false positive cases in this age.

Objetivo: Estabelecer parâmetros de condução nervosa para o eletrodiagnóstico da síndrome do túnel do carpo (STC) em idosos. Método: Foram estudadas 30 pessoas idosas (65-86 anos) saudáveis. Foi realizado estudo de condução nervosa sensitiva e motora rotineira dos nervos mediano e ulnar, latência palmar mista do mediano, técnicas de comparação de latências mediano-ulnar (sensitivo, misto e motor lumbrical-interósseo) e mediano-radial (sensitivo) e índice sensitivo combinado (ISC) em ambas as mãos. Resultados: Os limites superiores de normalidade, 97,5 por cento foram: latência distal sensitiva do mediano 3,80 ms (14 cm); latência distal motora do mediano 4,30 ms (8 cm), latência palmar do mediano 2,45 ms (8 cm), diferença de latência lumbrical-interósseo 0,60 ms (8 cm), comparação mediano-radial 0,95 ms (10 cm), comparação mediano-ulnar 0,95 ms (14 cm), comparação mediano-ulnar palmar 0,50 ms (8 cm) e ISC 2,20 ms. As latências sensitivas e mistas foram medidas no pico. Conclusão: Nossos resultados estabelecem novos valores de condução nervosa para o eletrodiagnóstico da STC leve em idosos.

Comparison between surface electrode and monopolar needle electrode in the determination of the nerve conduction studies of the radial nerve

OBJECTIVE: This cross-sectional study aims to determine the accuracy of using a surface electrode compared with using a needle electrode in the determination of the latency, amplitude, and duration of the compound motor action potential and nerve conduction velocity of the radial nerve.METHODS: A cohort of 42 males and 30 females consisting of patients from the Philippine General Hospital referred for electrodiagnostic studies of the upper extremity and healthy volunteers were included in the study. The compound motor action potential of the radial nerve in each participant was determined using the surface electrode technique and the mono polar needle technique, and the results were compared. The man outcome measures were: compound motor action potential amplitude, latency, duration, and nerve conduction velocity; sensitivity; specificity; and agreement between the two techniques under investigation. RESULTS: When all parameters in the nerve conduction studies were considered, the sensitivity of the surface electrode compared with the mono polar needle electrode in determining radial nerve abnormalities was 46.14% (95% Confidence Interval (CI) 0.27 - 0.65), with a specificity of 82.61% (95% CI 0.72 - 0.94) and an overall diagnostic accuracy of 69.44%. When the parameters were taken individually, analysis of the latency showed sensitivity of 60% (95% CI 0.17 - 1.03), and specificity of 100%, with overall diagnostic accuracy of 97.22%. The test for amplitude yielded sensitivity of 50% (95% CI 0.1 - 0.90) and specificity of 100%. The overall diagnostic accuracy was 95.83%. Analysis of the duration showed a sensitivity of 71.43% (95% CI 0.38 - 1.05) and specificity of 100%, with overall diagnostic accuracy of 97.22%. The nerve conduction velocity alone showed sensitivity of 55% (95% CI 0.33 - 0.77), specificity of 84.61% (95% CI 0.75 - 0.94), and overall diagnostic accuracy of 76.39%. The kappa test revealed a fair association or agreement when all the parameters of the compound motor action potential were taken into consideration (k=0.30), moderate association between the surface and the needle electrode in nerve conduction velocity (k=0.40), a substantial association in nerve conduction velocity (k=0.40), a substantial association in amplitude (k=0.65) and latency (k=0.74), and a high association between the two techniques for the duration (k=0.81). CONCLUSIONS: In the comparison of the surface electrode and the mono polar needle electrode techniques in the determination of the compound motor action potential of the radial nerve, the parameters have high specificity and a high probability of a negative test in individuals who are disease-free. The kappa test indicated a fair association between the two techniques. When the parameters of compound motor action potential are taken separately, the latency, amplitude, duration and nerve conduction velocity of the radial nerve have a high probability of positive test results in people with disease and a high probability of negative test results in people with no disease. The study showed that the surface electrode technique is a fair to good alternative to the needle electrode when conducting a radial motor nerve study.

Carpal tunnel syndrome: long-term nerve conduction studies in 261 hands / Síndrome do tunel do carpo: estudo evolutivo de parâmetros de condução nervoso em 261 mãos

OBJECTIVE: To compare a long-term carpal tunnel syndrome (CTS) on nerve conduction studies (NCS) in hands treated non-surgically. METHOD: We retrospectively selected 261 symptomatic CTS hands (166 patients), all of them confirmed by NCS. In all cases, at least 2 NCS were performed in an interval greater than 12 months. Cases with associated polyneuropathy were excluded. NCS parameters for CTS electrodiagnosis included a sensory conduction velocity (SCV) <46.6 m/s (wrist to index finger, 14 cm) and distal motor latency (DML) >4.25 ms (wrist to APB, 8 cm). RESULTS: 92.8 percent were women; mean age was 49 years (20-76); the mean interval between NCS was 47 months (12-150). In the first exam, the median sensory nerve action potential (SNAP) and the compound action muscular potential were absent in 9.8 percent and 1.9 percent, respectively. In the second/last exam, SCV worsened in 54.2 percent, remained unchanged in 11.6 percent and improved in 34.2 percent. SNAP amplitude worsened in 57.7 percent, remained unchanged in 13.1 percent and improved in 29.2 percent. DML worsened in 52.9 percent, remained unchanged in 7.6 percent and improved in 39.5 percent. Overall, NCS parameters worsened in 54.9 percent, improved in 34.3 percent and remained unchanged in 10.8 percent. CONCLUSION: Long-term changing in NCS of CTS hands apparently were not related to clinical symptomatology and could lead to some difficulty in clinical correlation and prognosis. Aging, male gender and absent SNAP were more related to NCS worsening, regardless the mean interval time between the NCS.

OBJETIVO: Comparar evolutivamente parâmetros de condução nervosa (CN) na síndrome do túnel do carpo (STC) em mãos não submetidas à cirurgia. MÉTODO: Foram selecionadas retrospectivamente 261 mãos (166 pacientes) com STC sintomática confirmadas por CN e que posteriormente realizaram exame controle com intervalo >12 meses; foram excluídos casos com polineuropatia. Os parâmetros eletrodiagnósticos anormais foram: velocidade de condução sensitiva (VCS) <46,6 m/s, segmento pulso-II dedo, e latência distal motora (LDM) >4,25 ms, segmento pulso-APB (8 cm). RESULTADOS: 92,8 por cento eram mulheres; a média de idade foi 49 anos (20-76); o tempo médio entre os exames foi 47 meses (12-150); 9,8 por cento e 1,9 por cento não apresentaram potenciais de ação do nervo sensitivo (PANS) e potenciais de ação muscular compostos, no primeiro exame. No segundo exame a VCS piorou em 54,2 por cento, ficou igual em 11,6 por cento e melhorou em 34,2 por cento; a amplitude do PANS piorou em 57,7 por cento, ficou igual em 13,1 por cento e melhorou em 29,2 por cento; a LDM piorou em 52,9 por cento, ficou igual em 7,6 por cento e melhorou em 39,5 por cento. Incluindo todos os parâmetros eletrofisiológicos, houve piora em 54,9 por cento, melhora em 34,3 por cento e permaneceram sem alterações 10,8 por cento. CONCLUSÃO: As anormalidades da CN na STC podem oscilar ao longo do tempo e aparentemente independem da sintomatologia clínica, dificultando a correlação e prognóstico; idade mais avançada, sexo masculino e PANS ausentes no primeiro exame foram as variáveis que tiveram menor percentual de melhora evolutiva, independentemente do intervalo entre os exames.