Adjunctive non-pharmacological interventions for motor symptoms in Parkinson’s disease: a scoping review of randomized controlled trials

Abstract

Background Motor symptoms in Parkinson’s disease (PD), particularly gait, balance, freezing, and axial impairment, can remain troublesome despite optimized dopaminergic treatment. The literature on non-pharmacological adjuncts is diverse, and the label “complementary and alternative therapy” is used inconsistently across conventional rehabilitation, mind–body practices, acupuncture, cueing, and neuromodulation. Objective To map randomized evidence on adjunctive non-pharmacological interventions for PD motor symptoms, while distinguishing complementary/integrative practices from conventional rehabilitation and other adjunctive technologies. Methods We conducted a PRISMA-ScR-guided scoping review of PubMed and Web of Science from 1 January 2015 to 7 September 2025. English- or Chinese-language randomized controlled, randomized crossover, pilot, or feasibility trials were eligible when at least one prespecified motor or motor-function outcome was reported. Published reports and independent trials were counted separately. Non-motor outcomes were not synthesized unless they were ancillary to an otherwise eligible motor-focused trial. Results After a study-level and report-level audit, 50 eligible reports representing 48 independent randomized trials were retained. Seven reports evaluated rehabilitation or technology-assisted training, 15 mind–body or exercise-based approaches, eight acupuncture-related or manual approaches, and 20 neuromodulation, cueing, biofeedback, or other physical interventions. Study size, intervention dose, comparator choice, motor phenotype, outcome selection, follow-up, and safety reporting varied substantially. Two pairs of publications were identified as reports from the same trial families. Conclusion The randomized literature is broad but methodologically heterogeneous. This scoping review maps where motor outcomes have been studied; it does not establish comparative efficacy or justify treatment recommendations. Future trials and evidence syntheses should distinguish intervention classes more precisely, link multiple reports from the same trial, prespecify motor phenotypes and core outcomes, and report adverse events and adherence consistently. Systematic review registration https://osf.io/tu5nd/, DOI: 10.17605/OSF.IO/UKH9G.