Comparison between acupuncture therapy and gabapentin for chronic pain: a pilot study.

BACKGROUND: We examined whether the effect of true electroacupuncture on pain and functionality in chronic pain participants can be differentiated from that of medication (gabapentin) by analyzing quantitative sensory testing (QST). METHODS: We recruited chronic back and neck pain participants who received six sessions (twice weekly) of true electroacupuncture versus sham electroacupuncture or 3 weeks of gabapentin versus placebo treatment. QST profiles, pain scores, and functionality profile were obtained at baseline (visit 1) and after three sessions (visit 4) or six sessions (visit 7) of acupuncture or 3 weeks of gabapentin or placebo. RESULTS: A total of 50 participants were analyzed. We found no differences in QST profile changes (p = 0.892), pain reduction (p = 0.222), or functionality (p = 0.254) between the four groups. A major limitation of this pilot study was the limited number of study participants in each group. CONCLUSION: This pilot study suggests that a large-scale clinical study with an adequate sample size would be warranted to compare acupuncture and medication therapy for chronic pain management. TRIAL REGISTRATION NUMBER: NCT01678586 (ClinicalTrials.gov).

Chronic Opioid Therapy Modifies QST Changes After Ketamine Infusion in Chronic Pain Patients.

The long-term effects of opioids on sensitization processes are believed to be mediated through the N-methyl-D-aspartate receptor. Quantitative sensory testing (QST) changes observed after a ketamine infusion have been previously described but the effect that chronic opioids will have is not known. The results of this prospective randomized factorial trial compared the thermal QST changes observed after a .05 mg/kg ketamine infusion or a saline placebo in chronic pain subjects who were either opioid-naive or were chronically using opioids for chronic noncancer pain are presented. No baseline QST differences were noted between the 4 groups at baseline. Comparison of changes preinfusion with postinfusion QST measurements resulted in decreased average change in temporal summation response between opioid subjects who received a placebo compared with those who received a ketamine infusion (-5.22, SD = 9.96 vs 13.81, SD = 19.55; P = .004). Additionally, the average change in temporal summation was decreased among subjects who received a ketamine infusion and were not chronically using opioids compared with subjects who were using chronic opioids and received a placebo infusion (-1.91, SD = 13.25 vs 13.81, SD = 19.55; P = .007). The results indicate that low-dose ketamine infusions produce subtle changes in QST phenotypes that are modified by the chronic use of opioids. This illustrates the potential diagnostic and therapeutic value of ketamine in the setting of chronic opioid use. PERSPECTIVE: The presented data further our understanding of modulation of sensory perception in the setting of chronic opioid use and the role of the N-methyl-D-aspartate receptor. The use of low-dose ketamine infusions may be useful for the treatment as well as diagnosis of opioid-related neuropathic conditions.