Transcutaneous electrical nerve stimulation, acupuncture, and spinal cord stimulation on neuropathic, inflammatory and, non-inflammatory pain in rat models

Karina Laurenti Sato; Luciana Sayuri Sanada; Morgana Duarte da Silva; Rodrigo Okubo; Kathleen A Sluka

doi:10.3344/kjp.2020.33.2.121

Transcutaneous electrical nerve stimulation, acupuncture, and spinal cord stimulation on neuropathic, inflammatory and, non-inflammatory pain in rat models

Korean J Pain. 2020 Apr 1;33(2):121-130. doi: 10.3344/kjp.2020.33.2.121.

Authors

Karina Laurenti Sato¹, Luciana Sayuri Sanada², Morgana Duarte da Silva³, Rodrigo Okubo², Kathleen A Sluka⁴

Affiliations

¹ Department of Physical Therapy, Federal University of Sergipe, Sao Cristovao, Brazil.
² Department of Physical Therapy, Physiotherapy Postgraduate Program, Santa Catarina State University, Florianopolis, Brazil.
³ Department of Physical Therapy, Federal University of Pampa, Uruguaiana, Brazil.
⁴ Department of Physical Therapy and Rehabilitation Science, Pain Research Program, University of Iowa, Iowa City, IA, USA.

Abstract

Background: Transcutaneous electrical nerve stimulation (TENS), manual acupuncture (MA), and spinal cord stimulation (SCS) are used to treat a variety of pain conditions. These non-pharmacological treatments are often thought to work through similar mechanisms, and thus should have similar effects for different types of pain. However, it is unclear if each of these treatments work equally well on each type of pain condition. The purpose of this study was to compared the effects of TENS, MA, and SCS on neuropathic, inflammatory, and non-inflammatory pain models.

Methods: TENS 60 Hz, 200 μs, 90% motor threshold (MT), SCS was applied at 60 Hz, an intensity of 90% MT, and a 0.25 ms pulse width. MA was performed by inserting a stainless-steel needle to a depth of about 4-5 mm at the Sanyinjiao (SP6) and Zusanli (ST36) acupoints on a spared nerve injury (SNI), knee joint inflammation (3% carrageenan), and non-inflammatory muscle pain (intramuscular pH 4.0 injections) in rats. Mechanical withdrawal thresholds of the paw, muscle, and/or joint were assessed before and after induction of the pain model, and daily before and after treatment.

Results: The reduced withdrawal thresholds were significantly reversed by application of either TENS or SCS (P < 0.05). MA, on the other hand, increased the withdrawal threshold in animals with SNI and joint inflammation, but not chronic muscle pain.

Conclusions: TENS and SCS produce similar effects in neuropathic, inflammatory and non-inflammatory muscle pain models while MA is only effective in inflammatory and neuropathic pain models.

Keywords: Acupuncture Therapy; Inflammation; Knee Joint; Myalgia; Neuralgia; Pain; Spinal Cord Stimulation; Transcutaneous Electric Nerve Stimulation.