Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 
    Users Online: 28
Home Print this page Email this page Small font size Default font size Increase font size


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2013  |  Volume : 2  |  Issue : 3  |  Page : 194-201

Measurement of F wave components in a sample of healthy Iraqis: Normative data


1 Neurophysiology Unit, Gazi-Al Hariri Hospital, Medical City, Baghdad, Iraq
2 Department of Medical Physiology, College of Medicine, Al Nahrain University, Baghdad, Iraq
3 Department of Medical Physiology, College of Medicine, Baghdad University, Baghdad, Iraq

Date of Web Publication14-Feb-2014

Correspondence Address:
Farqad B Hamdan
Department of Medical Physiology, College of Medicine, Al-Nahrain University, Baghdad
Iraq
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/2278-0521.127065

Rights and Permissions
  Abstract 

Background: F-waves are late responses often incorporated during performance of nerve conduction studies and have become an integral part of the electrodiagnostic examination. Objective: To study uncommonly measured F-wave parameters and to establish normative data in our country. Materials and Methods: The study included 126 healthy individuals aged between 18 to 55 years. F-waves minimum, mean and maximum latencies, persistence, F-amplitude, F-conduction velocity, chronodispersion, Tacheodispersion, and F-ratio were studied by surface electrodes from the abductor pollicis brevis, abductor digiti minimi, abductor hallucis, and extensor digitorum brevis by stimulating the median, ulnar, tibial, and common peroneal nerves, respectively. Results: Different F-wave parameters were presented in the manuscript. F-wave latencies were correlated with limb length and height. Conclusion: F-wave latencies correlate better to the limb length than the height. The use of F-wave latencies without such correlation may lead to an erroneous conclusion. F-wave parameters should be performed in routine nerve conduction studies.

Keywords: F-wave parameters, healthy subjects, Iraqi


How to cite this article:
Mohsen SS, Hamdan FB, Mohammed NH. Measurement of F wave components in a sample of healthy Iraqis: Normative data. Saudi J Health Sci 2013;2:194-201

How to cite this URL:
Mohsen SS, Hamdan FB, Mohammed NH. Measurement of F wave components in a sample of healthy Iraqis: Normative data. Saudi J Health Sci [serial online] 2013 [cited 2022 Jan 22];2:194-201. Available from: https://www.saudijhealthsci.org/text.asp?2013/2/3/194/127065


  Introduction Top


F wave was first described and designated as a late response by Magladery and McDougal. [1] They are produced by antidromic activation "backfiring" of motor neurons, [2] thus its measurement helps in assessing motor conduction along the entire length of the peripheral axons, including the most proximal segment. [3]

F waves are low-amplitude and ubiquitous responses inherently variable in amplitude, latency and configuration but occur grouped within a consistent range of latencies. [2] Because of their utilities and ease, its measurement has since gained popularity in evaluation of a variety of neurologic conditions as part of routine nerve conduction studies.

Measuring F wave in the extremities is frequently used to evaluate peripheral nerve function, [4],[5] demyelinating radiculoneuropathies, [6] radiculopathies, [5],[7],[8] neurogenic atrophy, [9] spinal stenosis and multilevel root injury, [10] increased central excitability states such as upper motor neuron, [11] and central nervous system lesions. [12]

The accuracy of defining normal values is improved by considering F wave variables such as F wave latency which is directly related to height, limb length and to a lesser degree age, [13],[14],[15],[16] minimum F wave latency (Fmin), [17] F wave mean latency (Fmean), [18] F wave maximum latency (Fmax), [19],[20] F wave conduction velocity (FwCV), [21] F wave amplitude (Fampl), [22] F wave persistence (Fp), [23],[24] F wave chronodispersion (Fchrono), [25] F wave tacheodispersion (Ftacheo), [25],[26] and F wave ratio (Fr). [27]

The intension of this study is to evaluate various parameters of F wave in a sample of healthy individuals in our region as well as to study effect of different physiological parameters on it; and to compare our results with the normative data published in literature.


  Materials and Methods Top


This study was conduct at the EMG unit, Gazi Al-Hariri Teaching Hospital and Al-Kadhimiya Teaching Hospital, Baghdad-Iraq during the period from January to July 2011.

One hundred and twenty six healthy individuals were selected from healthy volunteers between age group of 18 to 55 years after getting their informed written consent to participate in the study. They comprised 68 females with mean age of 36.49 ± 9.93 years and 58 males with a mean age of 32.82 ± 10.27 years. An approval from Institutional Ethics Committee was obtained.

All subjects were included in the study when they have normal neurological examination, normal laboratory findings regarding serum sugar, electrolytes and renal function. A standardized questionnaire was used to exclude those with a history of systemic or neuromuscular diseases. Moreover, those with a history of alcohol abuse or medications that might affect the results, those with a history of diabetes mellitus, hypothyroidism and systemic diseases were excluded.

F-waves were studied by micromed-8 channel EMG device, serial No. GH17H9NW315431B, model 171S, Italy. The room temperature was maintained relatively around 25 o C during the examination. The subjects were lying comfortably in the supine position and standardized technique was used to obtain and record action potentials for motor function measurements. [3]

The recording surface electrode was placed on abductor pollicis brevis for median, on abductor digiti minimi for ulnar nerve, on extensor digitorum brevis for peroneal and on abductor hallucis for tibial nerve. Reference electrode was placed 4 cm distally over first metacarpo-phalangeal joint for median, over fifth metacarpo-phalangeal joint for ulnar, over the proximal portion between third and fourth metatarso-phalangeal joint for peroneal and over proximal portion of first metatarso- phalangeal joint for tibial nerve. Stimulation of nerve was done at wrist for median and ulnar nerves and ankle for tibial and common peroneal nerves and the ground electrode was placed between stimulation and recording surface electrode.

The Fmin, Fmean and Fmax latencies, Fc, Fp, FwCV, and Fr values were determined for each nerve. Ftacheo was calculated by subtracting the minimum F wave conduction velocity (FWCV min) from maximum F wave conduction velocity (FWCV max).

Each nerve was stimulated supramaximally with stimulus frequency of 1 Hz, pulse duration of 0.2 ms and recordings were made with a sweep speed of 5 or 8 ms/cm and sensitivity of 0.2-0.5 mV/cm. For each nerve 10 successive stimuli were applied. [28]

The upper limb length was measured with a tape from the stimulus point to the C7 spinous process with the limb extended and abducted 90 o pronated for measurement of the ulnar nerve and supinated for the median nerve along the course of the nerve via the axilla and mid-clavicular point. For the lower limb, surface measurement followed the nerve course from the stimulus site to the T12 spinous process by way of the knee and greater trochanter of the femur.

Statistical package for the social science (SPSS), version 16 and Microsoft Office Excel 2007 were used for analyzing the data. ANOVA was used to analyze the relations among numeric data. The upper limit of the normal values was defined as mean plus two standard deviation (SD). Pearson's correlation coefficient was used to study correlation between two numeric variables. The probability limit (P value) of less than 0.05 was considered to be statistically significant.


  Results Top


The demographic features of 126 subjects enrolled in this study were presented in [Table 1]. Different F wave parameters for the upper and lower limbs are depicted in [Table 2].
Table 1: Demographic feature of the studied groups

Click here to view
Table 2: Different F-wave parameters of the tested nerves

Click here to view


Age showed significant effect on ulnar Flat mean, Fampl mim, and Fr max (P = <0.05). Moreover, age showed significant effect on median Flat mean (P = <0.05). Other F wave parameters not affected by age [Table 3].
Figure 3: Correlation between lower limb length and tibial F minimum amplitude

Click here to view


The gender had significant effect on ulnar Flat min (P = <0.05). Furthermore, it has significant effect on peroneal Fr min, Fr mean Fr max (P = <0.01), and Fc (P = <0.05) but none to other F wave parameters.

A positive correlations was observed between upper limb length and each of ulnar Fr max (P = <0.05) and Fc (P = <0.01) but not with the rest of parameters. Moreover, a positive correlation (P = 0.01) was shown between body height and ulnar Fp [Table 4] and [Figure 1].
Figure 1: Correlation between upper limb length and body height with ulnar F wave chronodipersion, maximum ratio, and persistence

Click here to view
Figure 4: Correlation between lower limb length and peroneal F minimum latency, minimum conduction velocity, minimum amplitude

Click here to view


Upper limb length was not correlated with different median F wave parameters while body height was negatively correlated (P = <0.05) with Fr mean [Table 5] and [Figure 2].
Figure 2: Correlation between body height and median F mean ratio

Click here to view
Figure 5: Correlation between body height and peroneal F minimum conduction velocity and minimum amplitude

Click here to view


The lower limb length but not the body height was correlated (P = 0.001) with tibial Fampl min out of the total F wave parameters [Table 6] and [Figure 3].{Figure 3}
Table 6: Correlations between limb length and body height and different F-wave parameters of tibial nerve

Click here to view


The lower limb length was positively correlated with peroneal Flat min, Fcv min (P = <0.01) and with Famp min (P = <0.0001). Moreover, body height was also positively correlated with Fcv min (P = <0.01) and Famp min (P = <0.05) as shown in [Table 7] and [Figure 4] and [Figure 5].{Figure 4}{Figure 5}
Table 7: Correlations between limb length and body height and different F wave parameters of the peroneal nerve

Click here to view



  Discussion Top


Nerve conduction study is useful diagnostic technique in many disorders affecting the nerves function since a specific diagnosis of the peripheral nerves and muscles disorders cannot be established by clinical evaluation alone. [3] F wave study is a type of nerve conduction procedure often performed as an integral part of electrodiagnosis.

The median F minimum and maximum latency and F chronodispersion in present study is in keeping with published studies. [29],[30] F chronodispersion values were in agreement with the findings of Ghosh, [30] but not with the observation of Panayiotopoulos. [31]

The F mean CV harmonize with findings of Cornwall and Nelson, [32],[33] likewise, F minimum CV coexistent with the observation of Kohara et al., [33] but in contrast to others, [32] in addition, F ratio was not consistent with Ghosh [30] findings.

With regard to ulnar nerve, F minimum, mean, and maximum latency and F chronodispersion was similar to that found by other researchers. [12],[29],[30],[34] Yet, our observation concerning F chronodispersion was higher than the findings of Kohora et al. [33] Ulnar F persistence, tacheodispoersion, F ratio, and F minimum, mean, and maximum CV values of the present study were in accordance with that of Kimura [35] but different from findings of others. [12],[30] Ulnar F minimum, mean, and maximum amplitude were different from those recorded by Chroni et al., [12] but within the range reported by other authors. [33]

Considering the tibial nerve, the F minimum, mean and maximum latency and F chronodispersion, F tacheodispersion, F persistence, and F minimum CV values were nearly similar to those reported worldwide. [20],[29],[33],[34],[36] The F minimum CV was different from that noticed by Fisher et al. [37] On the contrary, F mean CV was lower than that demonstrated by Fisher et al., [37] but higher than the value reported by Ohgaki et al. [38] The latter group found higher F ratio values than in our study.

In our study, common peroneal F minimum, mean, and maximum latency values were coexistent with the observation of other researchers, [5],[34],[39],[40] but different from the findings of Alavian-Ghanavini and Haghpanah [20] and Hatamian and Imamhadi. [15]

Our observation of F mean amplitude, F chronodispersion and F tacheodispersion were in accordance with the values published worldwide [36],[39],[40],[41] but higher than those reported by others. [5],[20],42

F wave latency has been reported to increase with height by 0.2 ms/cm in the upper and 0.4 ms/cm in the lower limbs. [29] The present data confirm in apart the well-known correlation of F wave latencies to the limb length and height.

In assessing the F minimum latency of the ulnar nerve, for example, a value (30.7 msec) considered below an upper limit of normal for a tall (180cm) subject would clearly indicate an abnormal delay for a short individual (160cm). F chronodispersion of median ulnar, tibial nerves remains the same regardless of the change in limb length and height also shown by others. [28]

Any index based on height has an inherent limitation because limb lengths vary in different individuals with the same height. Thus, limb index correlating latency and limb length showed a narrower range of variability than the height index. Similarly, F conduction velocity, based on the limb length, provide a practical measure in all individuals, regardless of their height. [33],[35]

Most of F wave values in the current study were coexistent with the published researches but few showing a considerable difference which could be attributed to difference in the distance between the stimulating and recording electrodes, age of the subjects studied, number of the subjects examined, diversity of the methods and techniques (studies differ in maneuvering, setting, recording the electrical response, and equipment used) and ethnic group studied.

Some studies were done on Caucasian subjects, others on Asian; however, none of the studies done between Caucasian populations living in different geographical areas. At present it is difficult to attribute the differences to a single factor. On the other hand, the diversity could have resulted for variables that were not yet considered by workers such as body built and climatic dwelling conditions.

Although some have recommended that normal values be segregated by sex, as a surrogate measure for anatomical difference we feel it is more appropriate to incorporate age, height and finger circumference into regression models used to predict normal values because there is considerable overlap between the female and male distributions of these factors.

In conclusion, association between each F wave measure and independent variables known or hypothesized to affect F wave was found to be statistically significant, biologically plausible, and clinically important and the use of F wave latencies without such correction may lead to an erroneous conclusion.


  Acknowledgment Top


We would like to thank all members of Neurophysiology Unit in Al-Kadhimiya Teaching Hospital and Gazi Al-Hariri Hospital, Medical city for their great help and their cooperation. Our gratitude also extended to all subjects who participated in this work.

 
  References Top

1.Magladery JW, McDougal DB Jr. Electrophysiological studies of nerve and reflex activity in normal man. I. Identification of certain reflexes in the electromyogram and the conduction velocity of peripheral nerve fibers. Bull Johns Hopkins Hosp 1950;86:265-90.  Back to cited text no. 1
    
2.Fisher MA. F-Waves-Physiology and Clinical Uses. Sci World J 2007;7:144-60.Kimura J. The F wave in health and disease. In: Electrodiagnosis in diseases of nerve and muscle: Principles and practice. New York: Oxford University Press, Inc.; 2001a. p. 427-30, 440-60.  Back to cited text no. 2
    
3.Kostera-Pruszczyk A, Rowiñska-Marciñska K, Owsiak S, Jezierski P, Emeryk-Szajewska B. F-wave amplitude in peripheral nervous system lesions. Neurol Neurochir Pol 2004;38:465-70.  Back to cited text no. 3
    
4.Sheki AA, Hamdan FB. The role of different neurophysiological tests in the differential diagnosis of diabetic axonal neuropathay and lumbosacral radiculopathy. Neuroscience (Riyadh) 2009;14:25-30.  Back to cited text no. 4
    
5.Geijo-Barrientos E, González O, Pastore-Olmedo C. Presence of repeater F-wave in the early stage of Guillain-Barré syndrome. J Peripher Nerv Syst 2012;17:128-31.  Back to cited text no. 5
    
6.Chan LL, Leoh TH, Lim W, Tan SW, Tan CT, Fook-Chong S. Diagnostic utility of F waves in cervical radiculopathy: Electrophysiological and magnetic resonance imaging correlation. Clin Neurol Neurosurg 2008;110:58-61.  Back to cited text no. 6
    
7.Gencer M, Uluc K, Cetinkaya Y, Isak B, Tireli H, Us O, et al. Clinical utility of F wave parameters in unilateral S1 radiculopathy. Neurosciences (Riyadh) 2011;16:237-41.  Back to cited text no. 7
[PUBMED]    
8.Macloed WN. Repeater F waves: A comparison of sensitivity with sensory antidromic wrist-to-palm latency and distal motor latency in the diagnosis of carpal tunnel syndrome. Neurology 1987;37:773-8.  Back to cited text no. 8
    
9.Bal S, Celiker R, Palaoglu S, Cila A. F wave studies of neurogenic intermittent claudication in lumbar spinal stenosis. Am J Phys Med Rehabil 2006;85:135-40.  Back to cited text no. 9
[PUBMED]    
10.Lukács M. F wave measurements detecting changes in motor neuron excitability after ischemic stroke. Electromyogr Clin Neurophysiol 2007;47:109-15.  Back to cited text no. 10
    
11.Chroni E, Katsoulas G, Argyriou AA, Sakellaropoulos GC, Polychronopoulos P, Nikiforidis G. Level of consciousness as a conditioning factor of F wave generation in stroke patients. Clin Neurophysiol 2006;117:315-9.  Back to cited text no. 11
[PUBMED]    
12.Toyokura M, Ishida A. Diagnostic sensitivity of predicted F-wave latency by age, height, and MCV. Acta Neurol Scand 2000;102:106-13.  Back to cited text no. 12
[PUBMED]    
13.Puksa L, Stålberg E, Falck B. Reference values of F wave parameters in healthy subjects. Clin Neurophysiol 2003;114:1079-90.  Back to cited text no. 13
    
14.Hatamian HR, Imamhadi MR. Determination of f-wave latency in individuals aged 20 years and older. Acta Med Iran 2005;43:212-4.  Back to cited text no. 14
    
15.Mahmoudi H, Salehi Z, Azma K, Rezasoltani Z, Omidzohour M. F wave to height or limb length ratios as rational alternatives for F wave latency in clinical electrodiagnostic medicine. Clin Neurophysiol 2011;122:2300-4.  Back to cited text no. 15
[PUBMED]    
16.Husain A, Habib SS, Omar SA, Al-Drees AM. Validity of F-wave minimal latency of median and ulnar nerves for diagnosis and severity assessment of carpal tunnel syndrome in type ii diabetes mellitus. Pak J Physiol 2011;7:3-6  Back to cited text no. 16
    
17.Raudino F. F-wave: Sample size and normative values. Electromyogr Clin Neurophysiol 1997;37:107-9.  Back to cited text no. 17
[PUBMED]    
18.Alavian-Ghavanini MR, Samadzadeh S, Alavian-Ghavanini A. Normal values of F wave in upper extremities of 50 healthy individuals in Iran. Electromyogr Clin Neurophysiol 1998;38:305-8.  Back to cited text no. 18
[PUBMED]    
19.Alavian-Ghavanini MR, Haghpanah S. Normal values of F wave in lower extremities of 73 healthy individuals in Iran. Electromyogr Clin Neurophysiol 2000;40:375-9.  Back to cited text no. 19
[PUBMED]    
20.Nobrega JA, Manzano GM, Novo NF, Monteagudo PT. F-waves and conduction velocities range. Electromyogr Clin Neurophysiol 2000;40:327-9.  Back to cited text no. 20
[PUBMED]    
21.Lin JZ, Floeter MK. Do F-wave measurements detect changes in motor neuron excitability? Muscle Nerve 2004;30:289-94.  Back to cited text no. 21
[PUBMED]    
22.Kong X, Gozani SN. An energy ratio based measure for F-wave backfiring rate estimation. Conf Proc IEEE Eng Med Biol Soc 2010;2010:3990-3.  Back to cited text no. 22
[PUBMED]    
23.Chroni E, Tendero IS, Punga AR, Stålberg E. Usefulness of assessing repeater F-waves in routine studies. Muscle Nerve 2012;45:477-85.  Back to cited text no. 23
    
24.Uludað B, Kisabay A, Ataç C, Karatepe A, Turman B. F Wave Parameters and F-Jitter. J Neurol Sci (Turkish) 2006;23:8-13.  Back to cited text no. 24
    
25.Tsai CT, Chen HW, Chang CW. Assessments of chronodispersion and tacheodispersion of F waves in patients with spinal cord injury. Am J Phys Med Rehabil 2003;82:498-503.  Back to cited text no. 25
[PUBMED]    
26.Husain A, Omar SA, Habib SS, Al-Drees AM, Hammad D. F-ratio, a surrogate marker of carpal tunnel syndrome. Neurosciences (Riyadh) 2009;14:19-24.  Back to cited text no. 26
[PUBMED]    
27.Peioglou-Harmoussi S, Fawcett PR, Howel D, Barwick DD. F response: A study of frequency, shape and amplitude characteristics in healthy control subjects. J Neurol Neurosurg Psychiatry 1985;48:1159-64.  Back to cited text no. 27
[PUBMED]    
28.Huang CR, Chang WN, Chang HW, Tsai NW, Lu CH. Effects of age, gender, height, and weight on late responses and nerve conduction study parameters. Acta Neurol Taiwan 2009;18:242-9.  Back to cited text no. 28
[PUBMED]    
29.Ghosh S. F-Wave parameters of normal ulnar and median nerves. Indian J Phys Med Rehabil 2010;21:47-50.  Back to cited text no. 29
    
30.Panayiotopoulos CP. F chronodispersion. A new electrophysiologic method. Muscle Nerve 1979;2:68-72.  Back to cited text no. 30
[PUBMED]    
31.Cornwall MW, Nelson C. Median nerve F-wave conduction in healthy subjects. Phys Ther 1984;64:1679-83.  Back to cited text no. 31
[PUBMED]    
32.Kohara N, Kimura J, Kaji R, Goto Y, Ishii J, Takigushi M, et al. Fwave latency serves as the most reproducible measure in nerve conduction studies of diabetic polyneuropathy: Multicentre analysis in healthy subjects and patients with diabetic polyneuropathy. Diabetologia 2000;43:915-21.  Back to cited text no. 32
    
33.Thakur D, Paudel BH, Bajaj BK, Jha CB. Nerve conduction study in healthy individuals: A gender based study. Health Renaissance, September-December 2010; Vol 8 (No. 3);169-175.  Back to cited text no. 33
    
34.Kimura J. Long and short of the nerve conduction measures: Reproducibility for sequential assessments. J Neurol Neurosurg Psychiatr 2001b; 71:427-30.  Back to cited text no. 34
[PUBMED]    
35.Tüzün E, Oge AE, Ertaþ M, Boyacíyan A, Dinççað N, Yazící J. F wave parameters and F tacheodispersion in mild diabetic neuropathy. Electromyogr Clin Neurophysiol 2001;41:273-9.  Back to cited text no. 35
    
36.Fisher MA, Chawla J, Webber CL Jr. Deterministic recurrences of sequential F-wave latencies. Neurol Neurophysiol Neurosci 2006;28:8.  Back to cited text no. 36
    
37.Ohgaki K, Nakano K, Shigeta H, Kitagawa Y, Nakamura N, Iwamoto K, et al. Ratio of motor nerve conduction velocity to F-wave conduction velocity in diabetic neuropathy. Diabetes Care 1998;21:615-8.  Back to cited text no. 37
[PUBMED]    
38.Karsidag S, Morali S, Sargin M, Salman S, Karsidag K, Us O. The electrophysiological findings of subclinical neuropathy in patients with recently diagnosed type 1 diabetes mellitus. Diabetes Res Clin Pract 2005;67:211-9.  Back to cited text no. 38
    
39.Kong X, Bansal P, Megerian JT, Gozani SN. Peroneal F-wave characteristics under submaximal stimulation. Neurol Neurophysiol Neurosci 2006;7:1.  Back to cited text no. 39
    
40.Nobrega JA, Pinheiro DS, Manzano GM, Kimura J. Various aspects of F-wave values in a healthy population. Clin Neurophysiol 2004;115:2336-42.  Back to cited text no. 40
    
41.Katirji B. The clinical electromyography examination: An overview. Neurol Clin 2002;20:11.  Back to cited text no. 41
    


    Figures

  [Figure 1], [Figure 2], [Table 3], [Table 4], [Table 5]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Materials and Me...
Results
Discussion
Acknowledgment
References
Article Figures
Article Tables

 Article Access Statistics
    Viewed3705    
    Printed89    
    Emailed0    
    PDF Downloaded222    
    Comments [Add]    

Recommend this journal