Systematic Review of Therapeutic Strategies for Reducing Parkinson’s Disease Symptoms and Progression

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor and non-motor symptoms, including cognitive decline, which plays a significant role in its pathogenesis. This systematic review aimed to evaluate the efficacy of therapeutic strategies in reducing symptoms and potentially slowing the progression of PD. This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. A systematic search was conducted across PubMed, MEDLINE, Europe PMC, EBSCO Open Dissertations, ScienceDirect, and the Cochrane Library for randomized controlled trials (RCTs) published between January 2015 and January 2025. Inclusion criteria focused on RCTs assessing therapeutic interventions aimed at slowing Parkinsonian symptoms and disease progression compared to placebo or standard care. Study quality was appraised using the Cochrane Risk of Bias-2 (RoB-2) tool. The review identified 15 RCTs that met the inclusion criteria. Interventions, such as exenatide and apomorphine, demonstrated improvements in motor symptoms, as measured by the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), often coupled with reductions in inflammatory markers like high-sensitivity C-reactive protein (hs-CRP). However, cognitive interventions yielded mixed results, showing benefits only in specific cognitive domains. The safety profiles varied significantly; for example, apomorphine (93% adverse events) exhibited substantially higher rates of adverse events compared to the placebo group (57%). Therapeutic strategies aimed at targeting PD symptoms show promise in managing both motor and non-motor manifestations of the disease. While benefits for cognitive decline are less consistent, these interventions warrant further investigation for their potential to slow overall disease progression. Future research should prioritize larger, multicenter RCTs with longer follow-up, explore combination therapies, and focus on identifying biomarkers for personalized treatment.