Efficacy of non-pharmacological treatments for prolonged disorders of consciousness: a network meta-analysis of randomized controlled trials

Objective: To explore the efficacy of non-pharmacological treatments such as repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), median nerve stimulation (MNS), hyperbaric oxygen (HBO), and acupuncture in improving the level of consciousness in patients with prolonged disorders of consciousness (pDOC). Methods: PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang, China Biology Medicine (CBM), and VIP Database were systematically searched from inception to December 2024. Data synthesis and visualization were conducted using the "coda" and "gemtc" packages in R software and STATA 17.0. The Jadad scale was used for initial screening to exclude low-quality studies, and the Cochrane Risk of Bias 2.0 tool was applied to assess the methodological quality of included randomized controlled trials (RCTs). Results: A total of 32 randomized controlled trials (RCTs) enrolling 1,770 participants were included in this network meta-analysis. The pooled results demonstrated that rTMS, tDCS, MNS, HBO, and acupuncture were all associated with improved scores on the Coma Recovery Scale-Revised (CRS-R). The mean difference (MD) ranged from 17.32 (95% CrI: 6.57 to 104.25) in the rTMS group to 3.56 (95% CrI: 0.61 to 40.45) in the acupuncture group. According to the Surface Under the Cumulative Ranking Curve (SUCRA), rTMS was associated with the highest probability of being the most effective intervention. In subgroup analyses, among patients with minimally conscious state (MCS), the MD ranged from 15.99 (95% CrI: 1.57 to 66.77) in the tDCS group to 9.72 (95% CrI: 2.07 to 61.04) in the MNS group, and among patients with unresponsive wakefulness syndrome (UWS), the MD ranged from 18.52 (95% CrI: 2.15 to 108.73) in the rTMS group to 4.12 (95% CrI: 0.25 to 69.30) in the acupuncture group. Conclusion: rTMS, tDCS, MNS, HBO, and acupuncture may improve CRS-R scores and promote consciousness recovery in patients with pDOC. Among these interventions, tDCS may be associated with more favorable effects in patients with MCS, whereas rTMS appears to be more beneficial for those with UWS.