Understanding central mechanisms of acupuncture analgesia using dynamic quantitative sensory testing: a review.

Jiang-Ti Kong,Sean Mackey,Rosa N Schnyer,Kevin A Johnson

doi:10.1155/2013/187182

Abstract

We discuss the emerging translational tools for the study of acupuncture analgesia with a focus on psychophysical methods. The gap between animal mechanistic studies and human clinical trials of acupuncture analgesia calls for effective translational tools that bridge neurophysiological data with meaningful clinical outcomes. Temporal summation (TS) and conditioned pain modulation (CPM) are two promising tools yet to be widely utilized. These psychophysical measures capture the state of the ascending facilitation and the descending inhibition of nociceptive transmission, respectively. We review the basic concepts and current methodologies underlying these measures in clinical pain research, and illustrate their application to research on acupuncture analgesia. Finally, we highlight the strengths and limitations of these research methods and make recommendations on future directions. The appropriate addition of TS and CPM to our current research armamentarium will facilitate our efforts to elucidate the central analgesic mechanisms of acupuncture in clinical populations.

Highlights

The treatment of chronic pain is the most well-known clinical application of acupuncture in the west [1, 2]
In addition to the classic neurotransmitters and anatomical pathways involved in central pain processing, other mechanisms contribute to acupuncture analgesia [6], including the hypothalamus-pituitary-adrenal axis [16], the autonomic nervous system [17, 18], and the glial system [19]
When pin pricks are used as the noxious stimuli, the German Research Network on Neuropathic Pain [65] recommends a standard protocol where either 128 or 56 mN pin tips are applied as a single stimulus and as a series of 10 stimuli given at 1 Hz

Summary

Introduction

The treatment of chronic pain is the most well-known clinical application of acupuncture in the west [1, 2]. In addition to the classic neurotransmitters and anatomical pathways involved in central pain processing, other mechanisms contribute to acupuncture analgesia [6], including the hypothalamus-pituitary-adrenal axis (regulating peripheral inflammatory response to pain) [16], the autonomic nervous system (regulating local circulation) [17, 18], and the glial system [19] (contributing to inflammation around spinal and cerebral neural pathways). To this end, we discuss the emerging translational research methods for assessing the central mechanisms of action of acupuncture analgesia in humans. We examine the current application of temporal summation and conditioned pain modulation to acupuncture research and make recommendations on future directions

Objectives

Methods

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Conclusion