High Temporal Summation of Pain Predicts Immediate Analgesic Effect of Acupuncture in Chronic Pain Patients-A Prospective Cohort Study.

Petra Iris Baeumler,Dominik Irnich,Peter Conzen

doi:10.3389/fnins.2019.00498

Petra Iris Baeumler, Dominik Irnich + Show 1 more

Open Access

https://doi.org/10.3389/fnins.2019.00498

Copy DOI

Abstract

Objectives: This prospective cohort study explored whether two distinguished sensory parameters predicted acupuncture effects in chronic pain patients; namely high temporal summation of pain (TS) indicating spinal synaptic facilitation as well as a low vibration detection threshold (VDT) indicating a loss of Aβ-fiber function.Methods: Pinprick induced TS and VDT were assessed by standardized, validated methods at the most painful body site and a pain free control site in 100 chronic pain patients receiving six acupuncture sessions as part of an interdisciplinary multimodal pain treatment (IMPT). Immediate change in pain intensity after the first acupuncture session (first treatment on the first day of IMPT) was assessed by the verbal rating scale (VRS, 0–100). After 4 weeks of treatment, patients indicated in a questionnaire whether acupuncture had relieved pain immediately and whether it had contributed to overall pain reduction and well-being after IMPT.Results: Logistic regression analysis revealed an association between high TS at the control site and a reduction in pain intensity of at least 30% (VRS) after the first acupuncture (OR [95%-CI] 4.3 [1.6–11.8]). Questionnaire ratings of immediate pain relief after acupuncture were associated with high TS at the control site (OR [95%-CI] 3.8 [1.4–10.2] any pain relief, OR [95%-CI] 5.5 [1.7–17.1] over 50% pain reduction) and at the pain site (OR [95%-CI] 3.2 [1.2–8.9] any pain relief). Appraisals of the contribution of acupuncture to overall pain reduction and well-being after IMPT were not associated with TS. The VDT was not associated with any outcome.Conclusion: This explorative study provides first-time evidence that high TS, especially at a pain free control site, but not VDT, might predict immediate analgesic response to acupuncture in chronic pain patients. Thus, highly centrally sensitized chronic pain patients might respond particularly well to acupuncture.

Highlights

IntroductionThe effectiveness of acupuncture is thought to be based among other mechanisms on its potential to reduce central sensitization processes that sustain chronic pain states
In the management of chronic pain it is crucial to identify effective treatments in order to minimize the patient’s risk of further chronification and to reduce health care costs (Main et al, 2008; Institute of Medicine, 2011)
We explored the association of temporal summation of pain (TS) and the vibration detection threshold (VDT), as evaluated by DFNS standards, with the immediate analgesic response to acupuncture and with the subjective evaluation of acupuncture effects after a whole treatment in chronic pain patients undergoing multimodal pain therapy

Summary

Introduction

The effectiveness of acupuncture is thought to be based among other mechanisms on its potential to reduce central sensitization processes that sustain chronic pain states. Quantitative sensory testing has proven to permit conclusions about sensitization mechanisms contributing to chronic pain (Arendt-Nielsen, 2015) and standardized methods have been developed. Those suggested by the German Research Network for Neuropathic Pain (DFNS) are applied in clinical practice (Rolke et al, 2006), show good test-retest and interobserver reliability (Geber et al, 2011) and come with the advantage of established reference values (Rolke et al, 2006)

Objectives

Methods

Results

Discussion

Conclusion