Short-and long-term responsiveness of deep brain stimulation on motor and cognitive outcomes in GBA vs. Non-GBA parkinson's disease: a systematic review and meta-analysis of observational studies
Clinical Snapshot
PICO Framework
| P — Population | Patients with Parkinson's disease with and without glucocerebrosidase (GBA) mutations undergoing deep brain stimulation |
| I — Intervention | Deep brain stimulation (DBS) |
| C — Comparator | GBA mutation carriers versus non-carriers |
| O — Outcomes | Motor function (off-medication state), levodopa equivalent daily dose reduction, cognitive performance (Mattis Dementia Rating Scale), with minimum one-year follow-up |
Bottom Line
This meta-analysis of observational studies demonstrates that deep brain stimulation provides comparable motor benefits and medication reduction in Parkinson's disease patients regardless of GBA mutation status. However, GBA carriers experience greater cognitive decline over long-term follow-up, particularly evident at five years post-DBS. While motor outcomes support DBS efficacy in both groups, the accelerated cognitive deterioration in GBA-positive patients warrants careful pre-operative counselling and enhanced post-operative cognitive monitoring. These findings should inform patient selection discussions and long-term care planning, though the observational nature of included studies limits causal inference. Clinicians should consider genetic testing as part of comprehensive DBS evaluation to optimise patient expectations and monitoring strategies.
Key Findings
P Value: Not specified
Effect Size: Significant improvements in both GBA carriers and non-carriers
Primary Outcome: Motor function improvement in off-medication state and levodopa equivalent daily dose reduction
Nnt Or Sensitivity: Greater cognitive decline in GBA carriers at 5-year follow-up using Mattis Dementia Rating Scale
Confidence Interval: Not reported in abstract
Clinical Application
Applicable to current DBS practice with consideration for genetic testing and counselling Relevant to Australian movement disorder centres; GBA testing may inform PBS-funded DBS patient selection and long-term monitoring protocols Parkinson's disease patients considering deep brain stimulation, particularly those with known or suspected GBA mutations
Abstract
Deep brain stimulation (DBS) is an established therapy for motor complications in Parkinson's disease (PD). Patients carrying glucocerebrosidase (GBA) mutations exhibit distinct disease trajectories, raising questions regarding potential differences in clinical outcomes following DBS compared with non-carriers. To evaluate short- and long-term motor, medication, and cognitive outcomes following DBS in patients with GBA-PD compared with non-GBA PD. We conducted a systematic review and meta-analysis of studies reporting clinical outcomes in PD patients with and without GBA mutations who underwent DBS and had a minimum follow-up of one year. Random-effects inverse variance models were applied, with subgroup analyses according to GBA status. DBS was associated with significant improvements in motor function in the off-medication state and sustained reductions in levodopa equivalent daily dose in both GBA carriers and non-carriers, with no significant between-group differences. Cognitive performance declined over long-term follow-up in both groups. At five years, greater cognitive decline, assessed using the Mattis Dementia Rating Scale, was observed among GBA-PD mutation carriers compared with non-carriers. Motor improvement and medication reduction following DBS were comparable between PD patients with and without GBA mutations. Over long-term follow-up, greater cognitive decline was observed among GBA-PD carriers.
References
- 1.Gonzales Romero, P. F., Bermejo Rosado, P., Paredes Torres, F., Váscones-Román, F. F., Limbania, D., Pichardo-Rojas, D., Quispe-Vicuña, C., Nuñez-Castellanos, C., Yazdanian, F., Warren, A. E., Pacheco-Barrios, N., & Rolston, J. D. (2026). Short-and long-term responsiveness of deep brain stimulation on motor and cognitive outcomes in GBA vs. Non-GBA parkinson's disease: a systematic review and meta-analysis of observational studies. Neurosurgical Review. https://doi.org/10.1212/WNL.0000000000214036
Related Research
Clinical spine surgery
An Introduction to Machine Learning for the Practicing Spine Surgeon
2 Aug 2026
Brain and behavior
Machine Learning-Based Prediction of Poor Outcomes in Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis
1 Aug 2026
Neurosurgical review
Development and external validation of a machine learning model for predicting postoperative hydrocephalus in 1,073 posterior fossa tumor patients
31 July 2026
This content is for educational purposes for healthcare professionals only and does not constitute clinical advice. Clinical decisions should be based on individual patient assessment, current guidelines, and appropriate specialist consultation. Editorial Standards · Privacy Policy · Terms of Service