A study by a team of US researchers has shown that an enhanced response to sham acupuncture (SA) may be present in fibromyalgia patients who are more sensitive to experimental-pressure stimuli. Fifty patients with fibromyalgia were randomised to receive either nine traditional acupuncture (TA) or nine SA treatments over a period of four weeks. During TA, needles were inserted at the points Baihui DU-20, ear Shenmen, Hegu L.I.-4, Quchi L.I.-11, Sanyinjiao SP-6, Taichong LIV-3, Yaglingquan GB-34 and Zusanli ST-36, and manually manipulated to elicit deqi. Sham acupuncture participants experienced a non–penetrating pricking sensation at nine non-acupuncture points. In addition, participants underwent brain scanning using proton magnetic resonance spectroscopy (PMRS). The results showed that patients with low pain sensitivity (LPS), but not those with high pain sensitivity (HPS), demonstrated a significantly reduced clinical response to SA. This was not the case for TA. The authors hypothesise that there may be a threshold of sensation that has to be exceeded for an acupuncture intervention to induce analgesia. This hypothesis is supported by the fact that that both LPS and HPS groups responded equally to TA. (Pressure Pain Sensitivity and Insular Combined Glutamate and Glutamine (Glx) Are Associated with Subsequent Clinical Response to Sham But Not Traditional Acupuncture in Patients Who Have Chronic Pain. Medical Acupuncture. April 2013, 25(2): 154-160).
Categories: Acupuncture research
