Pressure pain threshold and needle acupuncture in chronic tension-type headache – a double-blind placebo-controlled study

Abstract

In order to examine the role of muscular mechanisms in chronic tension-type headache a study with needle acupuncture was performed. Needle acupuncture could be of therapeutic value because it has shown some positive effects in myofascial pain syndromes. We performed a double-blind, placebo-controlled study with 39 patients (mean age 49.0 years, SD=14.8) fulfilling the International Headache Society criteria for chronic tension-type headaches. Participants were randomly assigned to verum or placebo condition. Six weeks after end of treatment no significant differences between placebo and verum could be observed with respect to visual analogue scale and frequency of headache attacks. Nevertheless, pressure pain thresholds significantly increased for the verum group. The findings of our study support the hypothesis that peripheral mechanisms - such as increased muscle tenderness - only play a minor role in the pathogenesis of chronic tension-type headache.

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

“…Four studies could be combined in an analysis regarding the immediate treatment effect [22,37,49,93], and two studies were analyzed regarding longterm effects of acupuncture in pain conditions [49,52]. The results of these metaanalyses confirm our descriptive findings.…”

“…In the following, the term ''sham'' is used according to the description of the respective publication. Sham interventions were needling at non-acupuncture points with stimulation (17 out of 48; 35.4%) [24, 25, 30, 31, 35, 42-44, 50, 53, 62, 73, 83-85, 94, 95], without or with minimal stimulation (10 out of 48; 20.8%) [22,27,37,44,46,47,57,86,93,95], minimal or no intensity needle stimulation at classical acupuncture points (10 out of 48; 20.8%) [40,44,66,80,88,92,95,97,103,104], non-penetrating placebo needles (12 out of 48; 25%) [28,33,45,52,60,61,72,76,78,79,98,99], or treatment with an inactive laser pen (5 out of 48; 10.4%) [31,48,49,77,95]. In 25 of these 48 studies (52.1%) the effect on sensory thresholds was significantly larger in the verum than in the sham acupuncture group [25, 28, 31, 33, 37, 40, 46, 50, 52, 57, 60, 62, 72, 76, 78-80, 83-85, 88, 92, 93, 95, 97].…”

“…Most common conditions under investigation were myofascial pain, associated with the occurrence of MTrPs (8 out 35, 22.9%) [33,38,41,48,50,63,70,83], fibromyalgia (7 out of 35, 20%) [37,44,45,72,81,82,87], chronic neck and back pain (5 out of 35, 14.3%) [22,46,49,74,77], temporomandibular disorder (5 out of 35, 14.3%) [40,43,68,79,91], and experimentally induced delayed-onset muscle soreness (DOMS; 4 out of 35, 11.4%) [27,47,51,78]. PPT was also used as an outcome measure for the treatment effect of acupuncture in tension type headache [52,93], osteoarthritis of the knee [86], abdominal scar pain [62], plantar fasciitis [96], and syringomyelia [64].…”

“…Nine of these reported the PPT to be significantly elevated [33,40,41,43,51,64,78,79,83], and one study found no significant PPT increase [50]. Among the 26 studies (74.3%) that assessed the effectiveness of an acupuncture series, 18 (69.2%) showed a PPT increase after treatment [37,38,46,50,52,62,63,68,70,72,74,77,81,82,86,87,91,93] while six studies (23.1%) observed no effect of acupuncture on the PPT [22,27,[47][48][49]96]. The outcome of two studies was rated as unclear, because the analysis was performed by combining data of all groups [44,45].…”

“…In all other studies (34 out of 35, 97.1%) algometers with different tip sizes (between 0.28 and 3.14 cm 2 ) were used to determine the PPT. In 23 studies, algometers were equipped with a rubber tip of 1 cm 2 or larger [27, 33, 37, 38, 40, 41, 44-48, 50, 62, 68, 70, 74, 79, 81, 82, 86, 87, 91, 96], while in five studies tips of smaller sizes were used [49,51,52,72,83,93]. In five articles no information was given about the characteristics of the algometer [22,43,63,77,78].…”