Impact Of Gender And Body Mass Index On Median And Ulnar Motor Nerve F Wave Latency In Healthy Late Teenagers (original) (raw)
Related papers
Effect of Gender on F Wave Minimal Latency in Healthy Adults
Journal of medical science and clinical research, 2017
Background: F waves are low amplitude late responses due to antidromic activation of motor neurons following peripheral nerve stimulation. It is important in electro diagnosis as it can assess proximal and distal nerve segments unlike conventional nerve conduction studies. F wave minimal latency is the most important and frequently checked F wave parameter. F wave minimal latency is more in males comparing females in many studies. Many authors explain this may be solely due the difference of height between male and female population as height is positively correlated with F wave minimal latency. But some other factors unique to males and females can also be reason of this difference. Aim: Aim of this study was to study the effect of gender in F wave minimal latency independent of height. Setting and Design: F wave study was done prospectively in 200 carefully screened healthy subjects of age group 20-50 years. The study group included equal proportion of males and females. F wave minimal latencies of median and tibial nerves were found out. Statistical Analysis Used: All statistical analyses were done with SPSS software version 16. F wave minimal latencies of median and tibial nerves were compared between male and female population using independent T test. Step wise linear regression analysis was done to find out the effect of gender independent of height. Result and Conclusion: Effect of gender on F wave minimal latency persisted even after nullifying the effect of height. The higher F wave minimal latency in males is not solely due to the difference in height. So gender wise reference data is to be used for proper interpretation of this electro diagnstic parameter
Effects of age, gender, height, and weight on late responses and nerve conduction study parameters
Acta neurologica Taiwanica, 2009
BACKGROUND Different methods in performing nerve conduction studies (NCS) yield different results. The results of NCS can also be affected by factors such as gender, age, height, and weight. This study aimed (1) to survey the effects of such factors, (2) to determine the importance of these factors, and (3) to analyze them for building equations in NCS and late response studies. METHODS NCS from the neurological screening tests of 101 individuals without spinal cord, root, nerve, neuro-muscular junction, muscular, or systemic diseases were collected and analyzed. RESULTS Subjects with older age had longer latencies, smaller amplitudes, and slower velocities compared with those in the younger age group. The change with age was greater in the median than in the ulnar nerve. Female subjects or those with lower weight had higher median and ulnar sensory amplitude. Females had shorter latency in the upper limbs and longer latency in the lower limbs by F-wave studies than males did. Heigh...
Sport Sciences for Health, 2019
Background Electromyographic (EMG), mechanomyographic (MMG) and force (F) signals combined analysis represents an interesting approach to partition the electrochemical and mechanical events contributing to total electromechanical delay, i.e., the time lag existing between the muscle activation and the onset of force generation. Aim The study sought to assess the differences in electromechanical delay due to sex, age, and physical activity level. Methods Electromechanical components were assessed on vastus lateralis muscle during a maximum voluntary contraction and electrically evoked contractions in 180 participants. During each contraction, the EMG, MMG and F signals were recorded. Electromechanical delays and its two components (Δt EMG-MMG, mainly electrochemical component; and Δt MMG-F, mainly mechanical component) were computed. Measurements' reliability (intraclass correlation coefficient, ICC) and sensitivity (minimum detectable changes at 95% confidence as a percentage, MDC 95%) were also calculated. Results ICC spanned from 0.89 to 0.97 with a percentage change of the standard error of the measurement (SEM%) ranging from 1.6 to 4.9%. MDC 95% values ranged between 3.1 and 9.8%. Longer electromechanical delay values were observed in: (1) women compared to men; (2) 40-45 years old compared to 30-35 years and 20-25 years; and (3) sedentary than active participants. Differences were accompanied by increments in Δt MMG-F but not in Δt EMG-MMG values. Conclusions The alterations in the whole electromechanical delay induced by sex, age, and physical activity level could be ascribed to the difference in the duration of the mechanical events included in the electromechanical delay, possibly due to modifications in the muscle-tendon unit characteristics.
Reference values of F wave parameters in healthy subjects
Clinical Neurophysiology, 2003
Objective and Methods: A large reference value database for F wave parameters was constructed with data from 121 to 196 healthy subjects; the age range of the subjects was 14-95 years. We studied the following parameters: minimum F wave latency (FMINLAT), mean F wave latency (FMEANLAT), maximum F wave latency (FMAXLAT), number of F waves/20 stimuli (FNUMBER) and F wave dispersion (FDISP ¼ FMAXLAT-FMINLAT). The median, ulnar, peroneal and tibial nerves were studied. Results: Height explains almost half of the FMINLAT variability. The F wave latency increases with height in the arms by 0.2 ms/cm and in legs 0.4 ms/cm. The effect of age on F wave latency in the arms is relatively small, only 0.03 ms/year; and in the legs age increases the FMINLAT by 0.1 ms/year. Gender does not affect FMINLAT in a systematic way. The peroneal nerve has slightly longer FMINLAT than the tibial nerve, while the FNUMBER is higher in the tibial nerve than the peroneal nerve. The differences between the ulnar and median nerve are slight. There is a very high correlation between all 3 latency parameters (FMINLAT, FMAXLAT and FMEANLAT), but no correlation between FDISP and FNUMBER and the other parameters. Side to side comparisons reveals no significant differences in any of the parameters except for the median nerve FMINLAT and FMEANLAT, which is 0.2 ms longer on the right than left. If side difference of more than 2 standard deviation is taken as the upper limit for normal, the side difference in arms is 1.4 ms and in legs 3 ms. In repeated studies the interexaminer variability is small; the correlation coefficient between the different F parameters is high (P. 0:6 in arms and P. 0:7 in legs). In the arms the upper limit for a significant difference of FMINLAT on repeated studies in the median nerve is 1.0 and 1.7 ms for the ulnar nerve. In the legs, FMINLAT for the peroneal nerve is 2.6 ms and for the tibial nerve is 2.1 ms. Conclusions: This large reference value database can be used not only to evaluate single measurements in relation with height and age, but also to compare right and left side and changes over time at repeated studies.
The F waves study in young healthy individuals
International Journal of Research in Medical Sciences, 2018
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.
Clinical Neurophysiology, 2009
Objective: Previous studies have shown that age, gender, and body mass index (BMI) affect amplitude of sensory nerve action potentials (SNAP), but the total effects of multiple factors or the most prominently affected nerves have not been elucidated. This study systematically investigated effects of these factors. Methods: Amplitude of SNAP of the median, ulnar, superficial radial, superficial peroneal, and sural nerves was measured in 105 healthy subjects. The effects of age, gender, and BMI on each nerve were estimated by multivariate linear regression analysis. Results: SNAP amplitude decreased with age in all five nerves. Women had greater SNAP amplitude than men in the upper limb nerves (median, ulnar, and radial), but not in the lower limb nerves (peroneal and sural). Similarly, greater BMI was associated with smaller amplitudes in the upper limb nerves, but not in the lower limb nerves. Multivariate analyses showed the three factors explained 50% of the variation in the median nerve, 46% in the ulnar nerve, and 22-32% in the remaining nerves. Conclusions: The effects of age, gender, and BMI on SNAP amplitudes are not identical in different sensory nerves. Age was strongly correlated with SNAP amplitude in the nerves tested, whereas gender and BMI affect amplitudes only in the upper limb nerves. Significance: Age, gender, and BMI should be taken into account in clinical practice, but the extent of influence depends on the sensory nerves examined.
Various aspects of F-wave values in a healthy population
Clinical Neurophysiology, 2004
Objective: To characterize various aspects of F-wave in a healthy population and establish normative data for future clinical use. Methods: A total of 100 healthy volunteers underwent sensory and motor nerve conduction studies of the ulnar and tibial nerves, including F waves elicited by 32 stimuli. Results: The F-wave measurements (mean^SD for ulnar vs tibial nerve) consisted of persistence (83^19 vs 97^5%), minimum, mean and maximum latencies (26.5^2.1, 28.1^2.2, and 30.4^2.3 vs 47.0^4.1, 49.6^4.4, and 52.5^4.4 ms), minimum, mean and maximum F-wave conduction velocities (FWCV) (55.0^2.7, 60.0^2.3, and 64.0^3.0 vs 49.0^2.9, 52.2^3.1, and 55.5^3.4 m/s), chronodispersion (3.9^0.9 vs 5.5^1.4 ms), mean amplitude (347^152 vs 384^148 mV) and mean duration (8.6^2.9 vs 13.0^4.5 ms). Additional measures, registered by electronic averaging, included latency (27.4^2.3 vs 48.6^4.7 ms), duration (9.6^2.2 vs 16.4^4.2 ms), and amplitude (299^156 vs 208^116 mV). Conclusions: The use of a height nomogram serves well as an acceptable means to adjust F latencies for the limb length. In addition to the commonly used minimal latency, maximal FWCV, and persistence, clinically relevant measures with a narrow variability includes mean and maximal latencies, chronodispersion, and mean duration. In particular, mean latency obtained with 10 stimuli gave accurate results either for group or individual analysis. Significance: The data help establish an adequate manner of recording F-wave latencies in clinical evaluation.
Physiological properties of single thenar motor units in the F-response of younger and older adults
Muscle & Nerve, 1994
The purpose of this study was to characterize the properties of single thenar motor units in the F-response of healthy younger (n = 15; age 33 & 1 1 years) and older subjects (n = 15; age 68 2 3 years). Trains of 300 stimuli at intensities evoking M-potentials lo%, 20%, and 30% of the peak-to-peak amplitude of the maximum M-potential, were delivered to the median nerve. In the young, observed firing probabilities of surfacedetected motor unit action potentials (S-MUAPs) extracted from the F-response ranged from less than 1-lo%, the S-MUAPs varied in size from 0.015% to 5.3% of the maximum M-potential negative peak area, and they were similar in size to the population of S-MUAPs collected by multiple point stimulation of the median nerve. The percentage difference between the slowest and fastest conducting fibers for individual subjects ranged from 8% to 20%, which translated to conduction velocities (CVs) of 48-68 m t s-' (mean 59 ? 4). The preceding were all independent of stimulus intensity. The S-MUAP sizes were significantly larger in older subjects (as%), and the range and distribution of motor unit CVs (38-61 m . s-'; mean 52 k 3) were markedly shifted to reflect a slower population of motor fibers. These findings suggest that age-related axonal slowing may uniformly affect all median motor fibers. 0 1994 John Wiley & Sons, Inc.
https://www.ijrrjournal.com/IJRR\_Vol.3\_Issue.6\_June2016/Abstract\_IJRR005.html, 2016
Nerve conduction study (NCS) provides an objective and quantitative measure of nerve function. A number of physiological variables, including age and gender, are known to affect the results of NCS. The present study investigated the effect of age and gender on motor and sensory parameters of NCS of Median nerve, including F-wave study. Study of the NCS records of 49 patients revealed higher compound motor action potential (CMAP) amplitude and longer F-wave latency in males whereas females had higher sensory nerve action potential (SNAP) amplitude. Further, with increasing age, latencies became longer, amplitudes became smaller and conduction velocities became slower. Therefore, age and gender of a person should be taken into consideration while interpreting his/her NCS results.