Transcranial Direct Current Stimulation (tDCS) Effects on Quantitative Sensory Testing (QST) and Nociceptive Processing in Healthy Subjects: A Systematic Review and Meta-Analysis

Abstract

Background: The aim of this study is to determine the effect that different tDCS protocols have on pain processing in healthy people, assessed using quantitative sensory tests (QST) and evoked pain intensity. Methods: We systematically searched in EMBASE, CINAHL, PubMed, PEDro, PsycInfo, and Web of Science. Articles on tDCS on a healthy population and regarding QST, such as pressure pain thresholds (PPT), heat pain thresholds (HPT), cold pain threshold (CPT), or evoked pain intensity were selected. Quality was analyzed using the Cochrane Risk of Bias Tool and PEDro scale. Results: Twenty-six RCTs were included in the qualitative analysis and sixteen in the meta-analysis. There were no significant differences in PPTs between tDCS and sham, but differences were observed when applying tDCS over S1 in PPTs compared to sham. Significant differences in CPTs were observed between tDCS and sham over DLPFC and differences in pain intensity were observed between tDCS and sham over M1. Non-significant effects were found for the effects of tDCS on HPTs. Conclusion: tDCS anodic over S1 stimulation increases PPTs, while a-tDCS over DLPFC affects CPTs. The HPTs with tDCS are worse. Finally, M1 a-tDCS seems to reduce evoked pain intensity in healthy subjects.

Critical review of the evidence for Vojta Therapy: a systematic review and meta-analysis

“…If the SDT of the difference was not provided, it was inferred from other data mentioned in the study: (1) utilizing other metrics reported in the study (for instance, confidence intervals and p -values, adhering to the principles outlined in Chapter 6.5.2.2 of the Cochrane Handbook) ( 17 ); or, if this was unattainable; (2) employing the correlation coefficient of the most analogous study included (adhering to the principles outlined in Chapter 6.5.2.8 of the Cochrane Handbook) ( 17 ); or if that was unattainable; (3) utilizing a conservative correlation coefficient of 0.5 ( 18 ). This methodology has been implemented in other meta-analyses ( 19 , 20 ).…”

Transcranial magnetic stimulation therapy for central post-stroke pain: systematic review and meta-analysis

“…In the absence of SD of the difference, we imputed from other data reported in the study: (1) using other measures reported in the study (e.g., confidence intervals and p values, following the principles described in Chapter 6.5.2.2 of the Cochrane Handbook) ( Higgins et al, 2023 ); or, if that was not possible, (2) using the correlation coefficient of the most similar study included (following the principles described in Chapter 6.5.2.8 of the Cochrane Handbook) ( Higgins et al, 2023 ); or if that was not possible, (3) using a conservative correlation coefficient of 0.5 ( Deeks et al, 2022 ). This methodology has been performed in other meta-analyses ( Gurdiel-Álvarez et al, 2023 ).…”