Motor Nerve Conduction Studies

2016 ◽  
pp. 257-291
Author(s):  
Lyell K. Jones ◽  
James C. Watson
Keyword(s):  
Action Potential ◽  
Nerve Conduction ◽  
Compound Muscle Action Potential ◽  
Motor Nerve ◽  
Conduction Block ◽  
Neuromuscular Diseases ◽  
Muscle Action ◽  
Motor Nerve Conduction ◽  
Muscle Action Potential ◽  
Nerve Disease

A compound muscle action potential (CMAP) is the summated action potential recorded from muscle during a motor nerve conduction study (NCS). Motor NCSs with recording of CMAPs may be used for several purposes in assessing neuromuscular diseases, including providing objective measurements of the extent and localization of the cause of weakness; determining the underlying pathological abnormality, such as conduction block or slowing of conduction at a localized area of neurapractic injury; identifying the changes associated with Wallerian degeneration and regeneration in the motor nerve; and assisting (along with needle EMG) in distinguishing peripheral nerve disease from lower motor neuron disease, neuromuscular junction disease, and myopathies. This chapter will review the concepts and techniques of motor NCS and CMAP recording, will describe the technique and measurements, and will discuss the findings in various neuromuscular diseases.

Late Responses

2016 ◽  
pp. 312-327
Author(s):  
Ruple S. Laughlin
Keyword(s):  
Nerve Conduction ◽  
Compound Muscle Action Potential ◽  
Motor Nerve ◽  
Clinical Applications ◽  
Nerve Conduction Studies ◽  
Sensory Nerves ◽  
Muscle Action ◽  
Physiological Basis ◽  
Motor Nerve Conduction ◽  
Muscle Action Potential

Late responses are a group of responses occurring after the compound muscle action potential (M-wave) in motor nerve conduction studies and include F-waves, H-reflexes, and axon reflexes. These responses can indirectly measure aspects of proximal conduction that are not obtained with routine motor nerve conduction studies and may be useful in assessing diseases that affect proximal nerves, such as polyradiculopathies. A thorough understanding of the physiological basis, sources of error, and clinical applications and limitations enhances the usefulness of F-waves and H-reflexes as one means to evaluate proximal functioning of the motor and sensory nerves. This chapter will discuss the study methods and applications of F-waves and H-reflexes.

scholarly journals Normal neurophysiologic parameters of the median nerve among adult healthy Sudanese population

2020 ◽  
Vol 10 (4) ◽  
pp. 136-141
Author(s):  
Mohammed Salah Elmagzoub ◽  
Ahmed Hassan Ahmed ◽  
Hussam M A Hameed
Keyword(s):  
Action Potential ◽  
Median Nerve ◽  
Conduction Velocity ◽  
Nerve Conduction ◽  
Compound Muscle Action Potential ◽  
Motor Nerve ◽  
Sensory Nerve ◽  
Peak Latency ◽  
Muscle Action Potential ◽  
Sensory Nerve Action

Background: Nerve conduction studies (NCSs) help in delineating the extent distribution of neural lesion, and the diagnosis of peripheral nerve disorders. Because normative nerve conduction parameters were not yet established in Sudan EMG laboratories, this study aims towards having our own reference values, as we are using the American and British parameters. This will allow avoiding the discrepancies that might be induced by many factors. Methods: NCSs were performed in 200 Median nerves of 100 adult healthy Sudanese subjects using standardized techniques. Results: The median SNAP (sensory nerve action potential) values were as follows: distal latency, 2.6±3 ms with a range of (2.3-2.9); peak latency, 3.5±0.5 ms (3.0-4.0); amplitude, 47.7±18.0μV (29.7-65.7); conduction velocity, 53.0±7.8 m/s (45.2-60.8). The following values were obtained for the Median nerve CMAP (compound muscle action potential) at wrist stimulation: distal latency, 3.5±0.5 ms with a range of (3.0-4.0); peak latency, 9.4± 1.0 ms (8.4-10.4); duration, 5.9±0.9 ms (5.0-6.8); amplitude, 12.3±2.5 mV (9.8-14.8); area, 43.0±10.4 mVms (32.6-53.4); conduction velocity, 63.6±6.2 m/s (57.4-69.8). The F wave was 28.4±1.8 ms (26.6-30.2). Conclusion: The overall mean sensory and motor nerve conduction parameters for the tested nerve compared favorably with the existing literature with some discrepancies that were justified.

Vincristine Neuropathy in Children: Squatting (Sitting Cross Legged) Predisposes Common Peroneal Nerves to Be More Severely Affected than Tibial Nerves

2019 ◽  
Vol 18 (04) ◽  
pp. 182-184
Author(s):  
Roshan Koul ◽  
Saleem Saleh Naiha Al Harousi ◽  
Sousan AlNabhani ◽  
Amna AlFutaisi
Keyword(s):  
Retrospective Study ◽  
Action Potential ◽  
Nerve Conduction ◽  
Nerve Conduction Velocity ◽  
Compound Muscle Action Potential ◽  
University Hospital ◽  
Muscle Action ◽  
Sultan Qaboos University ◽  
Muscle Action Potential ◽  
Vincristine Neuropathy

Abstract Objective The main objective of this article was to evaluate vincristine neuropathy effect on common peroneal and tibial nerves. Methods A retrospective study was conducted in children with vincristine neuropathy between August 2006 and January 2016 at Sultan Qaboos University Hospital. Results Twenty-eight children (15 females and 13 males) were included in the study. The compound muscle action potential of common peroneal nerves was significantly reduced relative to the tibial nerves (p < 0.05)). There was no difference in latency and nerve conduction velocity between the two nerves. Conclusion Children receiving vincristine demonstrate severe peroneal neuropathy compared with tibial nerves. We conclude that squatting posture effects peroneal nerves and postulate that the peroneal nerves are affected more due to the squatting posture. This squatting posture stretches the nerves that are already affected by the toxic effect of vincristine.

scholarly journals Nerve Conduction Study in Healthy Individuals: a Gender Based Study

1970 ◽  
Vol 8 (3) ◽  
pp. 169-175 ◽  
Author(s):  
Dilip Thakur ◽  
BH Paudel ◽  
BK Bajaj ◽  
CB Jha
Keyword(s):  
Action Potential ◽  
Nerve Conduction Study ◽  
Nerve Conduction ◽  
Compound Muscle Action Potential ◽  
Sensory Nerve ◽  
Sensory Nerve Action Potential ◽  
Muscle Action ◽  
Muscle Action Potential ◽  
Sensory Nerve Action ◽  
Motor Nerves

Background: Nerve conduction study (NCS) assesses peripheral nerve functions and has clinical implication. Objective: To study effect of gender on NCS variables in healthy adults. Settings and Design: Department of Physiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal. Material and Method: The study was done in 34 (m=19, 32±11 years; f=15, 32±12 years) consenting healthy adults. The compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) were recorded. Statistical analysis: The effect of gender on NCS variables was analyzed using Mann Whitney U test. Results: Male vs. female: males had increased CMAP and F-wave latencies (ms) in all tested motor nerves. CMAP duration (ms) was longer in males (p<0.05) in all tested motor nerves: right median (5.9±1.3 vs. 4.92±0.65), left median (5.54±0.91 vs. 4.72±0.57), right ulnar (5.55±1.01 vs. 4.56±0.59), left ulnar (5.71±0.97 vs. 4.64±0.51), right tibial (6.58±0.95 vs. 5.95±0.71), and left tibial (6.98±1.31 vs. 6.21±0.78). Females showed higher sural SNAP amplitude (µV) (23.26±9.23 vs. 15.94±8.42). SNAP duration (ms) was longer in males: right ulnar (1.16±0.19 vs. 1.03±0.06). SNAP latencies (ms) were also longer in males: right sural (2.61±0.44 vs. 2.21±0.36). Males had greater height (165.9±4.74 vs. 149.3±7.24) and weight (60.4±7.2 vs. 53±7.2).Conclusion: Gender has definite effects on NCS variables. Males had higher CMAP amplitude, longer latencies and duration. SNAP latencies and duration were longer in males whereas amplitude was higher in females. Without adjustment for these factors, the sensitivity and specificity of NCS will decrease when using the same reference data in patients with different gender. Keywords: compound muscle action potential; gender; nerve conduction study; sensory nerve action potential DOI: 10.3126/hren.v8i3.4210Health Renaissance, September-December 2010; Vol 8 (No.3);169-175

Age-Related Change in Peripheral Nerve Conduction: Compound Muscle Action Potential Duration and Dispersion

Gerontology ◽  
1999 ◽  
Vol 45 (3) ◽  
pp. 168-173 ◽  
Author(s):  
Katsumi Kurokawa ◽  
Yasuyo Mimori ◽  
Eiji Tanaka ◽  
Tatsuo Kohriyama ◽  
Shigenobu Nakamura
Keyword(s):  
Action Potential ◽  
Peripheral Nerve ◽  
Nerve Conduction ◽  
Action Potential Duration ◽  
Compound Muscle Action Potential ◽  
Muscle Action ◽  
Age Related ◽  
Muscle Action Potential

scholarly journals The Promising Application of a New Ulnar Nerve Compound Muscle Action Potential Measurement Montage in Amyotrophic Lateral Sclerosis

2022 ◽  
Author(s):  
Yixuan Zhang ◽  
Jingyue Ma ◽  
Shuo Zhang ◽  
Zhou Yu ◽  
Dongsheng Fan
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Action Potential ◽  
Ulnar Nerve ◽  
Nerve Conduction ◽  
Compound Muscle Action Potential ◽  
Muscle Action ◽  
Potential Measurement ◽  
Muscle Action Potential ◽  
Als Patients ◽  
Lateral Sclerosis

Abstract Objective Detecting peripheral nerve damage by electrophysiology examination accurately and sensitively is important for the follow-up evaluation of amyotrophic lateral sclerosis(ALS). In this study, we applied a new proximal E2 electrode in the ulnar motor nerve conduction study with E1 on abductor digiti minimi(ADM), and investigated its effect on the compound muscle action potential(CMAP) of the ulnar nerve. Methods We included 64 ALS patients and 64 age- and sex- matched controls. Patients characteristics were collected for phenotype, symptom duration and site of onset. The revised ALS Functional Rating Scale(ALSFRS-R) was evaluated at the time of administration to assess the severity of ALS. The ulnar nerve CMAP was recorded using an E1 electrode on the muscle belly and an E2 electrode on distal tendon(traditional montage, CMAP-dE2) and proximal tendon(new montage, CMAP-pE2) respectively. Results The waveform of CMAP-pE2 was steadier presenting a uniform unilobed pattern. In the controls, there were no significant differences between the amplitudes of CMAP-dE2 and CMAP-pE2(p=0.96). In ALS patients, the amplitude of CMAP-pE2 was significantly lower than that of CMAP-dE2(p<0.01), especially for patients with ADM spontaneous activity and muscular atrophy. Using the new method, the damaged axons were more likely to be stratified into more severe decreased levels. Furthermore, the decline of CMAP-pE2 was significantly correlated with ALSFRS-R(p<0.01). Conclusions The new electrode configuration in the ulnar nerve conduction test could reflect the degree of axonal injury much more sensitively after the presence of ulnar nerve degeneration and was more suitable for the evaluation of disease progression.

scholarly journals Nerve Conduction study in healthy individuals, a preliminary age based study

2012 ◽  
Vol 8 (3) ◽  
pp. 311-316 ◽  
Author(s):  
D Thakur ◽  
B H Paudel ◽  
C B Jha
Keyword(s):  
Action Potential ◽  
Nerve Conduction Study ◽  
Nerve Conduction ◽  
Compound Muscle Action Potential ◽  
Sensory Nerve ◽  
Muscle Action ◽  
Potential Amplitude ◽  
Muscle Action Potential ◽  
Motor Nerves ◽  
Effect Of Age

Background Nerve conduction study assesses peripheral nerve functions and has clinical implication. Objectives To study the effect of age on nerve conduction study variables in healthy adults. Methods Cross sectional study was done from Jan 2006 to Dec 2006 in department of Physiology, BP Koirala Institute of Health Sciences, Dharan, Nepal. The study was done in 34 (younger, n= 18, 17 to 29 years; older, n= 16, 30 to 57 years) consenting healthy adults of either sex. The compound muscle action potential and sensory nerve action potential were recorded using standard technique. Due to the non-normal distribution of data, the effect of age on nerve conduction study variables was analyzed using Mann Whitney U test. Results Younger vs. older individuals: older had lower Compound Muscle action potential amplitude (mV) in all motor nerves except radial and left ulnar nerves. Compound Muscle action potential duration (ms) was shorter in older (p<0.05) in ulnar, tibial, right median and left common peroneal motor nerves than the younger: right median (6.92±1.3 vs. 8.5±1.88), right ulnar (7.09±1.54vs. 8.2±1.31), left ulnar (10.56±1.44 vs. 12.06±1.5), right tibial (6.28±0.81vs. 7.28±1.12), and left tibial (9.58±1.52vs.10.78±1.71). Sensory nerve actional potential amplitude (?V) was smaller in older as compared to younger: right median (19.01±7.83 vs. 26.97±10.63), right ulnar (10.9±3.44 vs.16.09±5.85) and right radial (14.31±4.34 vs.19.72±6.47). SNAP duration (ms) was longer in older: right ulnar (1.34±0.17 vs.1.26± 0.18), left ulnar (1.46±0.14 vs. 1.29±0.26), and left median (1.11± 0.14 vs. 1± 0.14). Conclusions Age has definite effects on amplitude and duration of motor and sensory nerves. Different nerves have different timing of aging. Without adjustment for age, the sensitivity and specificity of nerve conduction study will decrease whenusing the same reference data in patients with different age.DOI: http://dx.doi.org/10.3126/kumj.v8i3.6218 Kathmandu Univ Med J 2010;8(3):311-6

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