Medical device-based neuromodulation for motor symptoms in Parkinson's disease: a systematic review and meta-analysis

Paulo E P Teixeira; João Victor Ribeiro; João Pedro Serrao Perin; Walter Augusto Fabris Moraes; Elly Angelica Pichardo; Ciro Ramos-Estebanez; Felipe Fregni; Tim Wagner; Laura Dipietro

doi:10.3389/fneur.2026.1731885

Medical device-based neuromodulation for motor symptoms in Parkinson's disease: a systematic review and meta-analysis

Front Neurol. 2026 Feb 12:17:1731885. doi: 10.3389/fneur.2026.1731885. eCollection 2026.

Authors

Paulo E P Teixeira¹, João Victor Ribeiro^{2

3}, João Pedro Serrao Perin^{2

3}, Walter Augusto Fabris Moraes^{2

4}, Elly Angelica Pichardo^{2

5}, Ciro Ramos-Estebanez⁶, Felipe Fregni^{2

5

7}, Tim Wagner^{1

8}, Laura Dipietro¹

Affiliations

¹ Highland Instruments, Cambridge, MA, United States.
² Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Mass General Brigham, Cambridge, MA, United States.
³ São Leopoldo Mandic School of Medicine and Dentistry, Campinas, Brazil.
⁴ Universidade de São Paulo, São Paulo, Brazil.
⁵ Epidemiology Department, Harvard T. H. Chan School of Public Health, Boston, MA, United States.
⁶ Departments of Neurology and Rehabilitation, and Neurosurgery, University of Illinois Chicago, Chicago, IL, United States.
⁷ Physical Medicine & Rehabilitation Department, Harvard Medical School, Boston, MA, United States.
⁸ Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States.

Abstract

Objective: To synthesize randomized clinical trial (RCT) evidence comparing the efficacy of medical device-based neuromodulation (MDBN) techniques for improving motor symptoms in Parkinson's disease (PD).

Background: Device-based neuromodulation therapies, including deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), and transcranial direct current stimulation (tDCS), are used to target PD motor symptoms, but reported effect sizes vary substantially across trials.

Methods: A systematic review was conducted in accordance with PRISMA guidelines. RCTs evaluating MDBN for PD motor function, measured by the Unified Parkinson's Disease Rating Scale Part III (UPDRS3), were identified through MEDLINE, Embase, and Web of Science. A random-effects meta-analysis was performed for the primary outcome (UPDRS3). Risk of bias was assessed using the Cochrane RoB tool, and certainty of evidence with GRADE. Meta-regression examined methodological, population, and intervention variables associated with effect size variation.

Results: Forty-seven RCTs (56 intervention comparisons; 2,638 participants) were included. Thirty trials investigated non-invasive neuromodulation (mainly rTMS and tDCS) and 17 invasive approaches (DBS). Meta-analysis of 39 effect sizes (from studies during L-Dopa ON, near-term follow-up) showed a small but significant improvement with active MDBN (SMD = -0.18, p = 0.008; I ² = 61%). Meta-regression showed larger effects in studies using intention-to-treat analysis and smaller effects when sham stimulation was used as a comparator.

Conclusion: MDBN is associated with modest yet significant motor improvements in PD. Effect size estimates are influenced by methodological characteristics, particularly analysis strategy and comparator selection. This is the first review in the field to calculate and incorporate separate effect sizes for each active intervention group in multi-arm trials, enabling more precise data inclusion.

Keywords: Parkinson’s disease; brain stimulation; motor function; neuromodulation; systematic review and meta-analysis.

Publication types

Systematic Review