A Review of Low-Power Laser Pain-Relieving Controlled Clinical Trials

Laser Acupuncture for Migraine and Muscle Tension Headache: A Double-Blind Controlled Trial

Twelve patients with chronic migraine recruited from a neurology clinic or a self-help group were randomly allocated to receive either 6 weeks active laser acupuncture or 6 weeks dummy laser acupuncture. Patients completed headache diaries for the 6 weeks prior to treatment and for 6 weeks following. They were then crossed over to receive the alternative treatment for a further 6 weeks. Neither patients nor operator knew which unit was the active one. There was a reduction in mean total headache score (combining duration and severity) of 18% in the active group and 43% in the control group following the first treatment period. This difference was not significant. Following the second treatment period, mean scores increased by 50% in the active group and 5% in the control group but again this difference was not significant due to inconsistent responses by some patients. When active and placebo treatments were computed for all patients, there were still no significant differences. It is concluded that laser acupuncture does not have an important clinical effect in migraine over and above the expected placebo response.

Ensuring Scientific Rigour in Literature Review

Literature reviews are an important method of summarising scientific data. However, many reviews are not themselves scientific. This has lead to some being inaccurate, on occasion dangerously so. Systematic literature reviews should involve six key elements: a clearly focused question; a thorough search for relevant studies; explicit criteria for including studies in the review; explicit criteria for judging the validity of the studies; an appropriate method of data synthesis; and suitable interpretation of the data presented. These ensure that the review is replicable and that reasons for the author's conclusions are explicit. Systematic reviews require considerable skills and resources. It is unlikely that all future reviews published in complementary medicine journals will constitute methodologically sound systematic reviews. It is suggested that authors of non-systematic reviews reflect on the possible shortcomings of their work and avoid making strong recommendations. Researchers should learn the skills of literature searching and critical appraisal.

Laser acupuncture: past, present, and future

Laser acupuncture is defined as the stimulation of traditional acupuncture points with low-intensity, nonthermal laser irradiation. Although the therapeutic use of laser acupuncture is rapidly gaining in popularity, objective evaluation of its efficacy in published studies is difficult because treatment parameters such as wavelength, irradiance, and beam profile are seldom fully described. The depth of laser energy transmission, likely an important determinant of efficacy, is governed not only by these parameters, but also by skin properties such as thickness, age, and pigmentation-factors which have also received little consideration in laser acupuncture. Despite the frequently equivocal nature of the published laser studies, recent evidence of visual cortex activation by laser acupuncture of foot points, together with the known ability of laser irradiation to induce cellular effects at subthermal thresholds, provides impetus for further research.