Effect of Action Observation Training along with Conventional Therapy in Patients with Parkinson’s Disease: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis investigated the efficacy of action observation training (AOT) combined with conventional therapy in improving motor and functional outcomes in patients with Parkinson’s disease (PD), particularly addressing freezing of gait (FOG) and overall quality of life. A comprehensive literature search was conducted across multiple databases, including MEDLINE, Cochrane Central, and Web of Science, for publications from 2013 to 2024. Six randomized controlled trials (RCTs) and one quasi-RCT involv-ing patients with Hoehn and Yahr stages I–IV were included. The intervention groups received AOT alongside conventional therapy, whereas the control groups received conventional therapy alone. The outcome measures included motor severity (Hoehn and Yahr scale, Movement Dis-order Society Unified Parkinson’s Disease Rating Scale), balance (BBS), gait (TUG, 6MWT, 10MWT), quality of life (PDQ-39), and FOG episodes (FOG-Q, NFOG-Q). Meta-analyses were conducted using a random-effects model. The meta-analysis demonstrated significant improvements in several clinical measures in the AOT group compared with the controls. Improvements were noted in FOG episodes (FOG-Q: mean difference, –2.03), walking speed (10MWT: mean difference, 0.67), balance (BBS: mean difference, –1.08), and quality of life (PDQ-39: mean difference, 5.68). AOT groups showed enhanced motor recovery and reduced FOG episodes, supported by evidence of improved neuroplasticity and functional reorganization within motor-related brain circuits. Substantial heterogeneity was observed in a few outcomes, such as the 10MWT, reflecting variability in study protocols. AOT combined with conventional therapy represents an innovative approach to neurorehabilitation for PD, offering superior outcomes compared with conventional therapy alone. By leveraging mirror neuron system activation, AOT facilitates motor learning and functional recovery in stroke patients. Despite limitations, such as small sample sizes and short follow-up durations in some studies, the findings strongly support the incorporation of AOT into clinical physiotherapy regimens. Future research should focus on large-scale RCTs with extended follow-up periods to further validate the benefits of this integrative approach.