Surgical Revision of Deep Brain Stimulation After Suboptimal Clinical Outcomes: A Systematic Review and Exploratory Meta-analysis

Background Some patients obtain less benefit than expected from deep brain stimulation (DBS) despite optimized programming. We systematically reviewed the outcomes of surgical revision in this setting. Methods Following PRISMA 2020, we searched PubMed, Embase and Scopus to October 2026 for studies of lead repositioning, replacement, added (rescue) leads or target switching performed for inadequate benefit or stimulation-related adverse effects; revision for infection or hardware failure was excluded. Outcomes were pooled with random-effects models, and certainty was rated with GRADE. Results Seventeen case series (approximately 149 patients) were included. Across 14 studies (95 patients), 81% (95% CI 68 to 91%) improved meaningfully, with similar estimates for same-target revision (82%) and for added or switched leads (79%). In Parkinson disease, the off-medication/on-stimulation motor score fell by 15.6 points after lead revision (95% CI 68 to 91%; four studies). Benefit was greatest when a lead outside the dorsolateral subthalamic nucleus was corrected and levodopa response was preserved. Seven studies reported surgical or hardware complications, and two deaths occurred. Certainty of evidence was very low. Conclusions Most published revised patients improve, but the evidence derives from small uncontrolled series. Revision should follow imaging, hardware checks and exhaustive reprogramming, within multidisciplinary review.