Selective Stimulation of C Fibers by an Intra-Epidermal Needle Electrode in Humans
Naofumi Otsuru1, 2, *, Koji Inui1, Koya Yamashiro1, 2, Takahiro Miyazaki1, 2, Ichiro Ohsawa3, Yasuyuki Takeshima1, Ryusuke Kakigi1, 2
Identifiers and Pagination:Year: 2009
First Page: 53
Last Page: 56
Publisher Id: TOPAINJ-2-53
Article History:Received Date: 23/04/2009
Revision Received Date: 12/06/2009
Acceptance Date: 17/06/2009
Electronic publication date: 10/8/2009
Collection year: 2009
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
We recorded evoked potentials (EPs) induced by intra-epidermal electrical stimulation using a needle electrode with specific parameters. We identified the fibers activated by this specific stimulation by assessing the conduction velocity (CV) of the peripheral nerve. The EPs were recorded from the Cz electrode (vertex) of the International 10-20 system in ten healthy male subjects. The dorsum of the left hand and forearm were stimulated with an intensity of 0.01 mA above the sensory threshold. The mean P1 latency of EPs for the hand and forearm were 1007 ± 88 and 783 ± 80 ms, respectively, and the CV estimated from the latency of P1 was 1.5 ± 0.7 m/s. The CV indicated that the fibers activated by the stimulation were C fibers. Since the method of stimulation is convenient and non-invasive, it should be useful for investigating the functions of small fibers.