Preoperative neuropsychological prognostic factors for deep brain stimulation in Parkinson's disease

Preoperative neuropsychological evaluation is standard in deep brain stimulation (DBS) candidacy assessment for Parkinson's disease (PD), but batteries vary substantially across centers and may require 6-8 h across multiple visits.

To synthesize evidence on preoperative neuropsychological prognostic factors for cognitive, functional, behavioral, speech, and quality-of-life outcomes following DBS and develop an evidence-informed assessment framework.

PubMed, Embase, and Scopus were searched through May 19, 2026. Eligible studies reported an identifiable preoperative neuropsychological measure associated with DBS candidacy or selection or with a postoperative outcome assessed at least 6 months after surgery. Two reviewers independently screened studies, extracted data, and assessed risk of bias using QUIPS and PROBAST. Evidence certainty was evaluated using GRADE.

Thirty-four studies comprising 3783 DBS patients were included. Among 311 extracted results, 238 involved an identifiable prognostic predictor, of which 117 (49.2%) reported adjusted multivariable estimates. Global cognition, executive function, and memory were evaluated as prognostic predictors in 21, 17, and 8 studies, respectively, with generally supportive directions when determinable. MDRS/DRS was most extensively studied but frequently directionally indeterminate, whereas MoCA, semantic/category fluency, and WCST each showed supportive directions in at least two studies. No instrument demonstrated comparative prognostic superiority.

Global cognition, executive function, and memory showed generally supportive but low-certainty prognostic associations. Based on these findings and consensus recommendations, we propose a standardized framework incorporating a clinical interview and streamlined testing battery requiring approximately 2 h to improve efficiency, consistency, and comparability across centers.