Comprehensive review of the optimal period for surgical treatment in parkinson’s disease progression : a meta analysis

Abstract

Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an established surgical intervention for advanced Parkinson’s disease (PD). However, the optimal timing for surgical intervention remains debated. This meta-analysis aims to evaluate the clinical efficacy of early versus late DBS based on disease progression.

Methods: A systematic search was conducted in PubMed, Scopus, Web of Science, ScienceDirect, and Google Scholar for studies published between January 2015 and July 2025. Eligible studies included randomized controlled trials comparing early (within ~5 years of diagnosis) and late STN-DBS in idiopathic PD patients. Primary outcomes included motor improvement (UPDRS-III), levodopa equivalent daily dose (LEDD) reduction, and quality of life (PDQ-39). Risk of bias was assessed using the Cochrane RoB tool, and data were pooled using RevMan 5.4.

Results: Six RCTs comprising 708 patients were included. Meta-analysis showed significantly greater motor improvement in the early DBS group (mean difference [MD] −7.45; 95% CI: −9.12 to −5.79; p < 0.001), greater LEDD reduction (MD −250.7 mg/day; 95% CI: −325.3 to −176.1; p < 0.001), and better quality of life scores (PDQ-39 MD −6.32; 95% CI: −8.79 to −3.84; p < 0.001). Heterogeneity was low to moderate across outcomes.

Conclusion: Early STN-DBS is associated with superior motor and quality-of-life outcomes and reduced medication burden compared to late intervention. These findings support reconsidering DBS timing in clinical practice, advocating for earlier surgical referral in appropriately selected patients with idiopathic PD.