Letters To The Editor
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 28, 2017; 23(20): 3758-3760
Published online May 28, 2017. doi: 10.3748/wjg.v23.i20.3758
Non-invasive stimulation techniques to relieve abdominal/pelvic pain: Is more always better?
Marie-Philippe Harvey, Alain Watier, Émilie Dufort Rouleau, Guillaume Léonard
Marie-Philippe Harvey, Guillaume Léonard, Research Centre on Aging, Université de Sherbrooke, Québec J1H 4C4, Canada
Alain Watier, Department of Gastroenterology, Sherbrooke University Hospital Centre, Sherbrooke, Québec J1G 2E8, Canada
Émilie Dufort Rouleau, Department of Pharmacy, Sherbrooke University Hospital Centre, Sherbrooke, Québec J1G 2E8, Canada
Guillaume Léonard, School of Rehabilitation, University of Sherbrooke, Québec J1H 5N4, Canada
Author contributions: Harvey MP, Watier A, Dufort Rouleau É and Léonard G contributed equally to this work; Watier A and Léonard G designed the research; Harvey MP and Dufort Rouleau É performed the research; Harvey MP and Léonard G analyzed the data; Harvey MP, Watier A, Dufort Rouleau É and Léonard G wrote the paper.
Supported by the Fonds de recherche en santé du Québec (FRQS), No. 29182.
Conflict-of-interest statement: Léonard G has received research funding from Fonds de recherche en santé du Québec; Watier A and Dufort Rouleau É are employees of the Sherbrooke University Hospital Centre; Watier A and Léonard G are employees of the University of Sherbrooke.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Guillaume Léonard, PT, PhD, Researcher, Research Centre on Aging, Université de Sherbrooke, 1036 rue Belvédère Sud, Québec J1H 4C4, Canada. guillaume.leonard2@usherbrooke.ca
Telephone: +1-819-780-2220 Fax: +1-819-820-6864
Received: November 17, 2016
Peer-review started: November 21, 2016
First decision: February 10, 2017
Revised: March 10, 2017
Accepted: April 12, 2017
Article in press: April 12, 2017
Published online: May 28, 2017
Abstract

Chronic abdominal and pelvic pain is a common condition that has significant impact on quality of life, and causes billions of dollars in direct and indirect costs. Emerging data suggest that transcranial direct current stimulation (tDCS), alone or in combination with transcutaneous electrical nerve stimulation (TENS), could be a promising therapeutic avenue to reduce chronic pain. The encouraging results coming from these studies prompted us to try combining TENS and tDCS in 4 of our patients who suffered from chronic abdominal/pelvic pain and to compare the effect with 5 other patients who received TENS alone. Pain intensity was assessed with a visual analog scale before, during and after the stimulation. We observed that there was a slight decrease in pain which was similar in both patient groups (TENS alone and TENS combined with tDCS). These observations suggest that combining TENS and tDCS in patients suffering from chronic pelvic and/or abdominal pain produces no additional benefit, compared to TENS alone. Future studies, looking at the effect of several/consecutive TENS and tDCS sessions should be conducted.

Keywords: Transcranial direct current stimulation, Transcutaneous electrical nerve stimulation, Pelvic pain, Abdominal pain, Chronic pain

Core tip: Past studies have showed that combining transcutaneous electrical nerve stimulation (TENS) and transcranial direct current stimulation (tDCS) can be an effective strategy to relieve chronic pain. In this letter, we describe the observations made on nine patients suffering from chronic pelvic and/or abdominal pain. Combining TENS and tDCS produced negligible effect on pain. The reduction in pain noted after the application of TENS and tDCS was comparable to the reduction noted after the application of TENS only. These clinical observations question the added value of tDCS in patients suffering from chronic pelvic and abdominal pain.