Transcranial Direct Current Stimulation for Knee Osteoarthritis: A Systematic Review and Meta‐Analysis of Randomized Controlled Trials

Abstract

BackgroundThe effects of transcranial direct current stimulation (tDCS) in the treatment of knee osteoarthritis (KOA) is still unclear.ObjectiveTo evaluate the efficacy and safety of tDCS in improving symptoms in patients with KOA.Data sources and study selectionThe following electronic databases were searched for eligible randomized controlled trials (RCTs): PubMed, EMBASE, Web of Science, and the Cochrane Library. The search was performed from the inception dates to April 30, 2023.Data extraction and synthesisData extraction and quality assessment were performed by 2 independent reviewers. Standard mean differences (SMDs) with 95% confidence intervals (95% CIs) for pooled data were calculated. A random‐effects model was used for the data analyses.Main outcomes and measuresThe primary outcomes were pain and physical function. Secondary outcomes included stiffness, mobility performance, quality of life, pressure pain tolerance, and plasma levels of brain‐derived neurotrophic factor (BDNF).ResultsThis meta‐analysis included 13 RCTs. tDCS was significantly associated with pain decrease compared with sham tDCS (SMD = ‐0.62, 95% CI: [‐0.87, ‐0.37], P < 0.00001). When compared tDCS plus other non‐tDCS with sham tDCS plus other non‐tDCS, there was no longer an significant association with pain decrease (SMD = ‐0.45, 95% CI: [‐1.08, 0.17], P = 0.16). The changes in physical function were not significantly different between the tDCS and sham tDCS groups. (SMD = ‐0.09, 95% CI: [‐0.56, 0.38], P = 0.71). When compared tDCS plus other non‐tDCS with sham tDCS plus other non‐tDCS, there was still no significant association with improvement in physical function (SMD = ‐0.66, 95% CI: [‐1.63, 0.30], P = 0.18). There was no significant difference with improvement in stiffness (SMD = ‐0.21, 95% CI: [‐0.77, 0.34], P = 0.45), mobility performance (SMD = 4.58, 95% CI: [‐9.21, 18.37], P = 0.51), quality of life (SMD = ‐7.01, 95% CI: [‐22.61, 8.59], P = 0.38), pressure pain tolerance (SMD = 0.30, 95% CI: [‐0.09, 0.69], P = 0.13). There was a statistically significant reduction in plasma levels of BDNF (SMD = ‐13.57, 95% CI: [‐24.23, ‐2.92], P = 0.01)ConclusionsIn conclusion, tDCS could significantly alleviate pain, but it might had no efficacy in physical function, stiffness, mobility performance, quality of life, pressure pain tolerance among KOA patients.

The Efficacy of the Addition of tDCS and TENS to an Education and Exercise Program in Subjects with Knee Osteoarthritis: A Randomized Controlled Trial

“…Many meta-analyses focusing on tDCS have been performed on different painful conditions to explore its effects on pain [ 24 , 25 ]. In the specific field of KOA, two meta-analyses recently examined the effect of tDCS on pain [ 26 , 27 ] but neither functional performance nor the psychosocial components of pain (kinesiophobia, catastrophizing), inherent in chronic pathologies, were explored.…”