Acupuncture effects of post-stroke thalamic pain: a systematic review and meta-analysis of randomized controlled trials

Background Post-stroke thalamic pain (PS-TP), a common form of central pain, is characterized by hyperalgesia and abnormal sensations in the contralateral affected area. Acupuncture treatment has shown increasing promise in treating PS-TP in recent years. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of acupuncture treatment for PS-TP. Methods According to the established search strategy, randomized controlled trials (RCTs) of acupuncture therapy for PS-TP were retrieved from eight Chinese and English databases as well as two clinical trial registration platforms, up to February 2024. Outcome measures included the total efficacy rate, visual analogue scale (VAS), present pain intensity score (PPI), pain rating index (PRI), beta-endorphin (beta-EP), substance P (SP) and adverse reactions. Sensitivity analysis and subgroup analysis were conducted to identify the sources of heterogeneity. We evaluated the evidence quality of outcomes via the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) rating system and performed trial sequential analyses using TSA software. Results The final inclusion comprised 12 articles, which involved 953 patients. Meta-analysis results indicated that acupuncture treatment for PS-TP was more effective than conventional medical treatment in reducing VAS scores [MD = -1.11, 95% CI (-1.33, -0.88), p = 0.002], PPI scores [MD = -0.65, 95% CI (-1.13, -0.16), p = 0.009], and PRI scores [MD = -1.02, 95% CI (-1.41, -0.63), p < 0.00001]. Additionally, acupuncture treatment for PS-TP was superior to the conventional medical treatment in increasing plasma beta-EP levels [MD = 8.83, 95% CI (5.42, 12.25), p < 0.00001], and reducing SP levels [MD = -4.75, 95% CI (-7.11, -2.40), p < 0.0001]. Regarding the total efficacy rate, acupuncture treatment was superior to the conventional medical treatment in treating PS-TP [RR = 1.24, 95% CI (1.17, 1.31), p < 0.00001]. The incidence of adverse events was lower in acupuncture treatment than in conventional medical treatment [RR = 0.43, 95% CI (0.14, 1.32), p = 0.03]. The GRADE assessment indicated that the quality of evidence for all outcome measures ranged from moderate to very low. Trial sequential analysis (TSA) results provided compelling evidence for the efficacy of acupuncture in treating PS-TP. Conclusion Acupuncture treatment emerges as a potentially efficacious and safe treatment option for PS-TP. In the future, more large-sample, high-quality RCTs are needed to provide primarily high-level evidence in evidence-based medicine regarding the safety and sustained effects of acupuncture treatment for PS-TP. Systematic review registration https://www.crd.york.ac.uk/PROSPERO/view/CRD42024498698, identifier CRD42024498698.