Electrical stimulation and electromagnetic field use in patients with diabetic neuropathy : systematic review and meta-analysis

Background: Painful diabetic neuropathy (PDN) is a common complication of diabetes mellitus, and pharmacological therapies are ineffective in many patients. Therefore, other treatment modalities should be considered, including electrical stimulation and electromagnetic fields. Objectives: The research objective was to evaluate the effect of treatment with electrical stimulation and electromagnetic fields on pain and sensitivity in patients with painful diabetic neuropathy compared with placebo or another intervention. Method: We searched the following electronic databases (from inception to April 2012): MEDLINE (accessed by PubMed), LILACS, Physiotherapy Evidence Database (PEDro), EMBASE and Cochrane CENTRAL. We included randomized trials that compared electrical stimulation or electromagnetic fields with control groups in which the objective was to assess pain and sensitivity in patients with PDN. Two reviewers independently extracted the data. A random-effects model was used for the main analysis. Results: The search retrieved 1336 articles, of which 12 studies were included. Reductions in the mean pain score were significantly greater in the TENS (transcutaneous electrical nerve stimulation) group than in the placebo group [–0.44 (95% CI: –0.79 to –0.09; I2: 0%)]. There was no improvement in pain relief when electromagnetic fields were compared with the control group [-0.69 (95% CI: –1.86 to 0.48; I2: 63%)]. Conclusions: We found that TENS improved pain relief in patients with diabetic neuropathy, while no such improvement was observed with the use of electromagnetic field treatment. Due to the methodological differences between the studies, a meta-analysis for the outcome of sensitivity could not be performed