Supplementary Material for: Efficacy of Unilateral Deep Brain Stimulation for Gait Enhancement in Parkinson’s Disease: ‎A Systematic Review and Meta-Analysis

Objective:‎

Bilateral electrode implantation is the primary approach for Deep Brain Stimulation (DBS) in ‎Parkinson’s Disease(PD). However, it may lead to gait deterioration in some patients. This ‎study aims to investigate the efficacy of unilateral DBS on gait in PD patients as an alternative ‎with fewer side effects and lower costs.‎

Method:‎

We systematically searched four major clinical databases to evaluate the effects of unilateral ‎DBS on UPDRS gait score, gait velocity, stride length, cadence, and gait initiation in PD ‎patients. 23 studies were included in the review, selected from an initial pool of 2,415 studies. ‎We also performed a meta-analysis to assess the impact of unilateral DBS on gait velocity and ‎compare its efficacy to bilateral stimulation. The study protocol was registered at PROSPERO ‎with the registration code: CRD42024585359.‎

Results:‎

The included studies assessed gait measures in patients receiving unilateral DBS targeting the ‎STN, globus pallidus internus, pedunculopontine nucleus, and ventral intermediate nucleus. ‎According to the systematic review of clinical evidence, unilateral DBS can improve the ‎UPDRS gait score, freezing of gait, and gait velocity, although to a lesser extent than bilateral ‎stimulation. The meta-analysis revealed a non-significant positive pooled effect on gait ‎velocity in the unilateral DBS condition compared to the control condition, and no significant ‎difference when compared to bilateral DBS. ‎

Conclusion:‎

‎Unilateral DBS shows promise for improving gait in Parkinson’s disease, as an alternative with ‎lower costs and side effects, especially in early-stage or asymmetric cases.‎