Transcranial Direct Current Stimulation (tDCS) in chronic low back pain: Systematic review with meta-analysis

Background and objective. Changes in grey matter of cortex and other parts of brain leads to increased pain perception in chronic low back pain (CLBP) patients which could be reduced by electrical application on these areas. The objective of the present review was to evaluate the efficacy of transcranial direct current stimulation (tDCS) alone as well as tDCS in combination with other interventions on pain in chronic low back pain patients. Method. PubMed and Cochrane search engines was used to locate the literature. The eligibility criterion for the study includes articles published in English language, published till March 2020 and the application of tDCS alone as well as in combination with other interventions on CLBP patients. Pain intensity was measured by visual analogue scale (VAS), numeric rating scale (NRS) or defense and veteran pain rating scale (DVPRS). Mean difference with 95% CI for the active tDCS, sham tDCS and tDCS in combination with other interventions was calculated. Result. 7 articles, with 427 patients, were included in the quantitative meta-analysis. The result showed statistically significant reduction in pain in tDCS alone as compared to sham tDCS Z= 1.93. P= 0.05 and insignificant reduction in pain in tDCS when used in combination with other intervention as compared to sham tDCS, Z= 0.72, P= 0.47 with heterogeneity of 84 % in the included studies. Conclusion. It can be concluded that there is significant reduction of pain in patients of chronic low back pain when tDCS is applied in isolation.