Psychophysical Responses in Acupuncture vs Sham Laser

The Neurological Basis of Acupuncture
The Neurological Basis of Acupuncture
Acupuncture and mock laser treatment yield similar psychophysical responses.

Results from a multicenter double-blind randomized trial recently reported in BMC Complementary and Alternative Medicine showed similar psychophysical responses with acupuncture and mock laser treatment.1

In traditional acupuncture, a concept that is central to achieving a therapeutic response is De Qi, which represents the sensory effects induced by the procedure.2,3 These psychophysical responses perceived at or close to the needling site often include soreness, tingling or numbness, pressure, and heaviness. Numerous scales have been developed that aim to quantify De Qi, including the Acupuncture Sensation Scale, the Massachusetts General Hospital (MGH) Acupuncture Sensation Scale (MASS), and the De Qi composite.

While De Qi typically refers to the effects of needling, it “can also be elicited without cutaneous sensory input, such as the use of laser acupuncture,” wrote the current authors in a previous study.4 Noting the potential value of De Qi as an indication for adequate “dosing” in acupuncture, they compared the De Qi resulting from acupuncture vs sham laser, which has been found to be a valid control in acupuncture trials.

The final sample included 84 adult patients (47 in the treatment group and 37 in the sham group) with lateral elbow pain. An inactive mock laser unit was used on blinded control participants. Each group underwent 3 sessions per week over a 3-week period. In the acupuncture group, stainless steel filiform needles were inserted at 2 classical acupoints, Large Intestine 11 (LI11-Quchi) and Large Intestine 10 (LI10-Shousanli). Both acupoints were stimulated for 2 minutes using a manual manipulation technique, and the needles were subsequently left in place for 24 minutes. A similar procedure was used in the control group, with the laser probe placed on the same acupoints for the same length of time.

Psychophysical responses were assessed with MASS, which includes 12 components of De Qi that are rated on a 10-point Likert scale (ranging from no sensation to unbearable). In addition, the MASS De Qi Index was used to assess the intensity of the De Qi.

The results show that, while both groups experienced similar De Qi responses, the acupuncture group reported significantly higher intensity at each session. Researchers used a Mann-Whitney U test to compare the intensity of De Qi values in the 2 groups; for similar De Qi distributions, medians were used; otherwise, mean ranks were employed. In session 1, the acupuncture group had a mean rank of 59.02 (interval range, 1 to 8.47) vs 23.18 (interval range, 0 to 6.59) in the mock laser group (U = 140, P <.001). In session 9, mean rank was 55.95 (interval range, 0.75-8.14) in the acupuncture group vs 26.99 (interval range, 0-7.21) in the mock laser group (U = 284.50, P <.001). The acupuncture group also reported a higher frequency of these effects (P <.001 for both).

With acupuncture, the most commonly reported responses were “soreness” and “aching” (92.5%), “deep pressure” (86%), “fullness/distension”and “heaviness” (80.8%), while the control group most commonly reported “tingling” (50%), “aching” (45.9%), and “sharp pain” (44.6%). According to the results of a credibility rating scale that was administered before treatment, the sham intervention was perceived by participants as adequate (P =.772) and credible (P =.768), which could help inform the design of future studies.

The researchers proposed that interoceptive awareness, defined as the level of attunement to internal bodily sensations, may “partially explain the psychophysical responses reported by the participants receiving the mock laser,” and suggested that this should be the focus of future research in this area.5


Similar effects were found for both acupuncture and sham laser, although responses were more frequent and intense for acupuncture.

Study Limitations

Small sample size and differing translated versions of the MASS across the 4 study sites.

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  1. Razavy S, Gadau M, Zhang SP, et al. Psychophysical responses in patients receiving a mock laser within context of an acupuncture clinical trial: an interoceptive perspective. BMC Complement Altern Med. 2017;17(1):348. doi:10.1186/s12906-017-1859-0
  2. Yang Y, Wang L-P, Zhang L, et al. Factors contributing to de Qi in acupuncture randomized clinical trials. Evid Based Complement Alternat Med. 2013;2013:329392. doi:10.1155/2013/329392
  3. Zhang S, Mu W, Xiao L, et al. Is deqi an indicator of clinical efficacy of acupuncture? A systematic review. Evid Based Complement Alternat Med. 2013;2013:750140. doi:10.1155/2013/750140
  4. Salih N, Baumler PI, Simang M, Irnich D. Deqi sensations without cutaneous sensory input: results of an RCT. BMC Complement Altern Med. 2010;10:81. doi:10.1186/1472-6882-10-81
  5. Bornemann B, Herbert BM, Mehling WE, Singer T. Differential changes in self-reported aspects of interoceptive awareness through three months of contemplative training. Front Psychol. 2015;5:1504. doi:10.3389/fpsyg.2014.01504