Effects of Acupuncture on Sensory Perception: A Systematic Review and Meta-Analysis

Abstract

Background: The effect of acupuncture on sensory perception has never been systematically reviewed; although, studies on acupuncture mechanisms are frequently based on the idea that changes in sensory thresholds reflect its effect on the nervous system. Methods: Pubmed, EMBASE and Scopus were screened for studies investigating the effect of acupuncture on thermal or mechanical detection or pain thresholds in humans published in English or German. A meta-analysis of high quality studies was performed. Results: Out of 3007 identified articles 85 were included. Sixty five studies showed that acupuncture affects at least one sensory threshold. Most studies assessed the pressure pain threshold of which 80% reported an increase after acupuncture. Significant short-and long-term effects on the pressure pain threshold in pain patients were revealed by two meta-analyses including four and two high quality studies, respectively. In over 60% of studies, acupuncture reduced sensitivity to noxious thermal stimuli, but measuring methods might influence results. Few but consistent data indicate that acupuncture reduces pin-prick like pain but not mechanical detection. Results on thermal detection are heterogeneous. Sensory threshold changes were equally frequent reported after manual acupuncture as after electroacupuncture. Among 48 sham-controlled studies, 25 showed stronger effects on sensory thresholds through verum than through sham acupuncture, but in 9 studies significant threshold changes were also observed after sham acupuncture. Overall, there is a lack of high quality acupuncture studies applying comprehensive assessments of sensory perception.

No Effect of Acupuncture in the Relief of Delayed-Onset Muscle Soreness

“…This is in accordance with a pilot study from Micklewright et al showing that soft tissue techniques failed at relieving DOMS 49 and with Frey Law et al 14 who showed deep tissue massage to be more effective than superficial touch in the reduction of experimental muscle pain. The hypothesis that acupuncture alters the PPT is supported by several experimental and clinical trials [50][51][52][53] and has lately been presented by Baeumler et al, 54 assuming that the PPT is the most affected sensory threshold and that effects on the mechanical pain sensitivity (detection) are less relevant.…”

Acupuncture for recurrent urinary tract infection in women: a systematic review and meta‐analysis

“…Despite the lack of biological plausibility, the finding that acupuncture may alter sensory perceptions, including perceptions of pain and reduced sensitivity for noxious thermal stimuli, 35 may be particularly important for women with rUTI. A qualitative study found cystitis-prone females reported improved pressure during micturition and more complete bladder emptying after acupuncture.…”

Comparative effect of electroacupuncture with different frequency on headache attacks in migraine outpatients: study protocol for a randomized controlled trial

“…Therefore, we designed a parallel-design, patient-assessor blind, RCT to explore the dominant frequency of EA on migraine. Studies had shown that negative emotion has a close relationship with pain diseases and changes on pain-related affection had been improved by acupuncture [25][26][27][28].…”