scholarly journals The F waves study in young healthy individuals

2018 ◽  
Vol 6 (5) ◽  
pp. 1628
Author(s):  
Subedi P. ◽  
Limbu N. ◽  
Thakur D. ◽  
Khadka R. ◽  
Gupta S.
Keyword(s):  
Early Stage ◽  
Compound Muscle Action Potential ◽  
Motor Nerve ◽  
Descriptive Analysis ◽  
Healthy Individuals ◽  
Anthropometric Parameters ◽  
Muscle Action Potential ◽  
Supramaximal Stimulation ◽  
F Wave ◽  
Stimulation Of

Background: The F wave is a CMAP (compound muscle action potential) evoked by a supramaximal stimulation of a motor nerve. F waves are particularly useful for the diagnoses of polyneuropathies at an early stage and proximal nerve lesions.Methods: Healthy males (n=64) and females (n=26) medical students of BPKIHS with age 20 to 24 years were enrolled. Anthropometric parameters; F wave latencies, persistence and chronodispersion of bilateral median, ulnar and tibial nerves were recorded in Neurophysiology Lab II of BPKIHS. Descriptive analysis was done.Results: Mean age, height and weight of the subjects were 21.64±1.19 years, 165.61±5.4cms and 64.07±5.5kg. Mean minimum F wave latencies (ms) of right median, ulnar and tibial nerves were 24.09±1.95, 24.02±1.76, 44.34±3.02 while on the left side were 23.92±1.96, 24.11±1.92, 44.07±2.83 respectively. F persistence was above 80%. F chronodispersion (ms) for right and left median, ulnar and tibial nerves were 2.77±0.70, 2.79±0.65, 2.71±0.67, 2.80±0.56, 3.48±0.73 and 3.45±0.64 respectively.Conclusions: Maximum and minimum F wave latencies, F chronodispersion and F persistence were derived for both sexes in an age group of 20-24 years.

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.

scholarly journals Head-down tilt bed rest with or without artificial gravity is not associated with motor unit remodeling

2020 ◽  
Vol 120 (11) ◽  
pp. 2407-2415 ◽  
Author(s):  
Julia Attias ◽  
Andrea Grassi ◽  
Alessandra Bosutti ◽  
Bergita Ganse ◽  
Hans Degens ◽  
...  
Keyword(s):  
Motor Unit ◽  
Compound Muscle Action Potential ◽  
Bed Rest ◽  
Artificial Gravity ◽  
Whole Body ◽  
Healthy Individuals ◽  
Long Duration ◽  
Muscle Action Potential ◽  
Abductor Digiti Minimi ◽  
Healthy Participants

Abstract Purpose The objective of this study was to assess whether artificial gravity attenuates any long-duration head-down 60 bed rest (HDBR)-induced alterations in motor unit (MU) properties. Methods Twenty-four healthy participants (16 men; 8 women; 26–54 years) underwent 60-day HDBR with (n = 16) or without (n = 8) 30 min artificial gravity daily induced by whole-body centrifugation. Compound muscle action potential (CMAP), MU number (MUNIX) and MU size (MUSIX) were estimated using the method of Motor Unit Number Index in the Abductor digiti minimi and tibialis anterior muscles 5 days before (BDC-5), and during day 4 (HDT4) and 59 (HDT59) of HDBR. Results The CMAP, MUNIX, and MUSIX at baseline did not change significantly in either muscle, irrespective of the intervention (p > 0.05). Across groups, there were no significant differences in any variable during HDBR, compared to BDC-5. Conclusion Sixty days of HDBR with or without artificial gravity does not induce alterations in motor unit number and size in the ADM or TA muscles in healthy individuals.

scholarly journals Recurrence Quantification Analysis of F-Waves and the Evaluation of Neuropathies

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Morris A. Fisher ◽  
Vijaya K. Patil ◽  
Charles L. Webber
Keyword(s):  
Compound Muscle Action Potential ◽  
Diabetic Neuropathies ◽  
The Other ◽  
Nonlinear Method ◽  
Abductor Hallucis ◽  
Muscle Action Potential ◽  
Abductor Hallucis Muscle ◽  
Quantification Analysis ◽  
Unique Method ◽  
F Wave

Electrodiagnostic (EDX) patterns of neuropathic dysfunction have been based on axonal/demyelinating criteria requiring prior assumptions. This has not produced classifications of desired sensitivity or specificity. Furthermore, standard nerve conduction studies have limited reproducibility. New methodologies in EDX seem important. Recurrent Quantification Analysis (RQA) is a nonlinear method for examining patterns of recurrence. RQA might provide a unique method for the EDX evaluation of neuropathies. RQA was used to analyze F-wave recordings from the abductor hallucis muscle in 61 patients with neuropathies. Twenty-nine of these patients had diabetes as the sole cause of their neuropathies. In the other 32 patients, the etiologies of the neuropathies were diverse. Commonly used EDX variables were also recorded. RQA data could separate the 29 patients with diabetic neuropathies from the other 32 patients (P<0.009). Statistically significant differences in two EDX variables were also present: compound muscle action potential amplitudes (P<0.007) and F-wave persistence (P<0.001). RQA analysis of F-waves seemed able to distinguish diabetic neuropathies from the other neuropathies studied, and this separation was associated with specific physiological abnormalities. This study would therefore support the idea that RQA of F-waves can distinguish between types of neuropathic dysfunction based on EDX data alone without prior assumptions.

Activity-dependent changes in intrinsic excitability of human spinal motoneurones produced by natural activity

2012 ◽  
Vol 108 (9) ◽  
pp. 2473-2480 ◽  
Author(s):  
Alessandro Rossi ◽  
Simone Rossi ◽  
Federica Ginanneschi
Keyword(s):  
Action Potential ◽  
Compound Muscle Action Potential ◽  
Intrinsic Excitability ◽  
Dependent Manner ◽  
Natural Activity ◽  
Muscle Action Potential ◽  
Abductor Digiti Minimi ◽  
F Wave ◽  
Spinal Motoneurones ◽  
Activity Dependent

The current study was designed to evaluate activity-dependent changes intrinsic to the spinal motoneurones (MNs) associated with sustained contractions. The excitability of spinal MNs (reflected by the antidromically evoked F-wave) innervating the abductor digiti minimi muscle (ADM) was measured in 12 healthy subjects following maximum voluntary contractions (MVCs) of ADM lasting 5 s, 15 s, 30 s, and 60 s. Upon cessation of the contractions, F-waves showed a depression, which increased in depth and duration with increasing duration of contraction. Following a 5-s contraction, there was a 20% decrease, which waned in 2 min, whereas a 60-s contraction produced a 40% decrease and waned in over 15 min. The changes in excitability of peripheral motor axons produced by the MVCs were measured by recording an ADM compound muscle action potential (CMAP) of ∼50% of maximum to a constant ulnar nerve electrical stimulation. On cessation of the contractions, there was a prominent decrease in size of the CMAP: following a 5-s MVC, it produced a 10% decrease in the size of the test CMAP, which recovered in 2 min, whereas following a 60-s MVC, it produced a 30% decrease, which recovered in over 15 min. Statistical analysis (correntropy) showed a high-order mutual dependence between F-wave and CMAP, and both were significantly dependent on MVC duration. Because of the parallel excitability changes in peripheral axons and spinal MNs, our interpretation is that intrinsic excitability of the axon initial segment (i.e., where the action potential is generated) and peripheral axon segments changed in a similar, activity-dependent manner.

scholarly journals Motor nerve conduction study parameters in healthy individuals: effect of limb dominance

2019 ◽  
Vol 7 (4) ◽  
pp. 1330
Author(s):  
Binnam Shakya ◽  
Dilip Thakur ◽  
Bishnu H. Paudel ◽  
Rita Khadka ◽  
Suman Pokhrel
Keyword(s):  
Ulnar Nerve ◽  
Nerve Conduction Study ◽  
Nerve Conduction ◽  
Motor Nerve ◽  
Healthy Individuals ◽  
Motor Nerve Conduction ◽  
Left Handed ◽  
F Wave ◽  
Wave Minimum ◽  
Limb Dominance

Background: Nerve conduction study (NCS) is useful for evaluation of nerve, muscle, and/or neuromuscular function. Neurophysiologist interprets NCS with consideration of various anthropometric and technical parameters viz. age, gender, height, temperature etc. apart from the underlying pathology. Fewer studies have reported the effect of limb dominance on NCS. Moreover, the findings are controversial. Therefore, author aimed to investigate the effect of limb dominance on motor nerve conduction study parameters.Methods: This cross-sectional comparative study included sixty healthy individuals (44 right and 16 left handed) of either sex with age 18 to 30 years. The NCS parameters of median and ulnar nerves were assessed by stimulating it and recording from the muscle and skin overlying the nerve respectively using Digital Nihon Kohden machine. The obtained data were analyzed using independent sample t-test.Results: Right ulnar nerve onset latency was significantly longer in left-handed individuals (1.85±0.508 ms vs 1.62±0.195 ms, p=0.012). The left ulnar nerve F wave minimum latency (25.88±0.74 ms vs 24.46±2.64 ms, p=0.002) was significantly longer in left-handed individuals. Likewise, right ulnar nerve distal latency (2.45±0.76 ms vs 2.14±0.39 ms, p=0.044), and right ulnar nerve F wave minimum (25.9±1.21 ms vs 24.85 ms±1.74, p=0.030) were significantly high in left-handed individuals.Conclusions: NCS parameters in terms of latencies were longer in left-handed individuals. Therefore, limb dominance seems to be an important factor one should pay attention during bilateral comparison of obtained data in neurophysiological reporting of referred cases.

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.

scholarly journals Arm posture-dependent changes in corticospinal excitability are largely spinal in origin

2016 ◽  
Vol 115 (4) ◽  
pp. 2076-2082 ◽  
Author(s):  
James L. Nuzzo ◽  
Gabriel S. Trajano ◽  
Benjamin K. Barry ◽  
Simon C. Gandevia ◽  
Janet L. Taylor
Keyword(s):  
Evoked Potentials ◽  
Biceps Brachii ◽  
Motor Evoked Potentials ◽  
Compound Muscle Action Potential ◽  
Corticospinal Excitability ◽  
Triceps Brachii ◽  
Upper Arm ◽  
Muscle Action Potential ◽  
Subcortical Stimulation ◽  
Stimulation Of

Biceps brachii motor evoked potentials (MEPs) from cortical stimulation are influenced by arm posture. We used subcortical stimulation of corticospinal axons to determine whether this postural effect is spinal in origin. While seated at rest, 12 subjects assumed several static arm postures, which varied in upper-arm (shoulder flexed, shoulder abducted, arm hanging to side) and forearm orientation (pronated, neutral, supinated). Transcranial magnetic stimulation over the contralateral motor cortex elicited MEPs in resting biceps and triceps brachii, and electrical stimulation of corticospinal tract axons at the cervicomedullary junction elicited cervicomedullary motor evoked potentials (CMEPs). MEPs and CMEPs were normalized to the maximal compound muscle action potential (Mmax). Responses in biceps were influenced by upper-arm and forearm orientation. For upper-arm orientation, biceps CMEPs were 68% smaller ( P = 0.001), and biceps MEPs 31% smaller ( P = 0.012), with the arm hanging to the side compared with when the shoulder was flexed. For forearm orientation, both biceps CMEPs and MEPs were 34% smaller (both P < 0.046) in pronation compared with supination. Responses in triceps were influenced by upper-arm, but not forearm, orientation. Triceps CMEPs were 46% smaller ( P = 0.007) with the arm hanging to the side compared with when the shoulder was flexed. Triceps MEPs and biceps and triceps MEP/CMEP ratios were unaffected by arm posture. The novel finding is that arm posture-dependent changes in corticospinal excitability in humans are largely spinal in origin. An interplay of multiple reflex inputs to motoneurons likely explains the results.

REGENERATION OF PERIPHERAL MOTOR NERVE GAPS WITH A POLYGLYCOLIC ACID-COLLAGEN TUBE

Neurosurgery ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. E1105-E1107 ◽  
Author(s):  
Yuji Inada ◽  
Hiroshi Hosoi ◽  
Akinori Yamashita ◽  
Shigeru Morimoto ◽  
Hideaki Tatsumi ◽  
...  
Keyword(s):  
Peripheral Nerves ◽  
Compound Muscle Action Potential ◽  
Motor Nerve ◽  
Polyglycolic Acid ◽  
Clinical Report ◽  
Guide Tube ◽  
Muscle Action Potential ◽  
Nerve Recovery ◽  
Electrophysiological Examination ◽  
Peripheral Motor

Abstract OBJECTIVE After previous success in regenerating canine peripheral nerves over 80 mm gaps using a bioabsorbable nerve guide tube, we have extended this method to the treatment of patients experiencing various types of nerve injury. This report describes the treatment of two cases of motor nerve disorder. METHODS The bioabsorbable nerve tube was a cylindrically woven polyglycolic acid (PGA) tube filled with collagen. A peripheral motor nerve defect (the frontalis branch of the facial nerve) was reconstructed using this PGA-collagen tube in two patients who experienced posttraumatic unilateral eyebrow ptosis for 3 months. RESULTS Five months after surgery, both patients regained their ability to voluntarily lift their eyebrows symmetrically. Electrophysiological examination at 5 months revealed recovery of compound muscle action potential and disappearance of distal latency on the affected side. CONCLUSION This is the first clinical report of motor nerve recovery achieved using the PGA-collagen nerve guide tube. The results suggest that use of a PGA-collagen tube is a promising option for the repair of motor nerve defects.

scholarly journals Phrenic nerve conduction studies: normative data and technical aspects

2017 ◽  
Vol 75 (12) ◽  
pp. 869-874 ◽  
Author(s):  
Analucia Abreu Maranhão ◽  
Sonia Regina da Silva Carvalho ◽  
Marcelo Ribeiro Caetano ◽  
Alexandre Hofke Alamy ◽  
Eduardo Mesquita Peixoto ◽  
...  
Keyword(s):  
Phrenic Nerve ◽  
Nerve Conduction ◽  
Normative Data ◽  
Compound Muscle Action Potential ◽  
Nerve Conduction Studies ◽  
Healthy Population ◽  
Lateral Border ◽  
Nerve Response ◽  
Muscle Action Potential ◽  
Stimulation Of

ABSTRACT Objective: The aim of the present study was to define normative data of phrenic nerve conduction parameters of a healthy population. Methods: Phrenic nerve conduction studies were performed in 27 healthy volunteers. Results: The normative limits for expiratory phrenic nerve compound muscle action potential were: amplitude (0.47 mv - 0.83 mv), latency (5.74 ms - 7.10 ms), area (6.20 ms/mv - 7.20 ms/mv) and duration (18.30 ms - 20.96 ms). Inspiratory normative limits were: amplitude (0.67 mv - 1.11 mv), latency (5.90 ms - 6.34 ms), area (5.62 ms/mv - 6.72 ms/mv) and duration (13.77 ms - 15.37 ms). Conclusion: The best point of phrenic nerve stimulus in the neck varies among individuals between the medial and lateral border of the clavicular head of the sternocleidomastoid muscle and stimulation of both sites, then choosing the best phrenic nerve response, seems to be the appropriate procedure.

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