title: A computational study to evaluate the activation pattern of nerve fibers in response to interferential currents stimulation.
abstract: Interferential current (IFC) is one of the most popular electrical currents used in electrotherapy. However, there have been limited studies investigating how this stimulation affects the nerve fibers. The aim of this computational study was to evaluate the temporal and spatial patterns of fiber activation in IFC therapy for different modulation and carrier frequencies. The interferential currents were applied by two pairs of point electrodes perpendicular to each other in an infinite homogeneous medium, and a model of myelinated nerve fibers was implemented in NEURON to study the neural response. The activation thresholds for different positions of the fiber and the resultant firing patterns were evaluated. The results suggest that the fibers may fire continuously or in bursts, with frequencies equal or higher than the modulation frequency, or may be blocked, based on their position relative to the electrodes, the modulation frequency and the stimulus strength. The results confirm traditional belief about the role of the modulation frequency in firing frequency of nerve fibers and describe a possible mechanism for less sensation of pain, due to blockage of the fibers by the high-frequency nature of the interferential currents.
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Isfahan, University St, Isfahan, Iran, mahsa_agharezaee@yahoo.com.
authors.forename: Mahsa
authors.initials: M
authors.lastname: Agharezaee
authors.forename: Amin
authors.initials: A
authors.lastname: Mahnam
mesh_terms: D019295:Computational Biology; D004599:Electric Stimulation Therapy; D004566:Electrodes; D008959:Models, Neurological; D009412:Nerve Fibers / Q000502:physiology*
references.citation: J Physiol. 1979 Jul;292:149-66
references.pmid: 314974
references.citation: Aust J Physiother. 1983 Dec;29(6):209-16
references.pmid: 25025829
references.citation: Br J Sports Med. 1990 Jun;24(2):87-92
references.pmid: 1702337
references.citation: Neuroscience. 1999 Mar;89(2):335-46
references.pmid: 10077317
references.citation: J Theor Biol. 1986 Nov 7;123(1):45-54
references.pmid: 3626584
references.citation: J Neurophysiol. 2002 Feb;87(2):995-1006
references.pmid: 11826063
references.citation: Med Biol Eng Comput. 1999 Mar;37(2):228-35
references.pmid: 10396827
references.citation: Med Biol Eng Comput. 2009 Mar;47(3):279-89
references.pmid: 19005714
references.citation: Med Biol Eng Comput. 2004 May;42(3):394-406
references.pmid: 15191086
references.citation: Phys Ther. 2009 Feb;89(2):181-90
references.pmid: 19095805
references.citation: Arch Phys Med Rehabil. 2004 Mar;85(3):409-15
references.pmid: 15031826
references.citation: Arch Phys Med Rehabil. 1998 Mar;79(3):273-8
references.pmid: 9523778
references.citation: Physiotherapy. 2011 Dec;97(4):319-26
references.pmid: 22051589
references.citation: IEEE Trans Biomed Eng. 2008 Feb;55(2 Pt 1):660-70
references.pmid: 18270002
references.citation: Arch Phys Med Rehabil. 1999 Sep;80(9):1065-71
references.pmid: 10489010