Preoperative Predictors of Postoperative Cognitive Outcomes Following Neurosurgery for Primary Brain Tumors: A Systematic Review

Background Cognitive impairment is common among patients with primary brain tumors and significantly impacts quality of life. Surgical resection can affect cognition, but postoperative outcomes vary widely across individuals. Identifying presurgical factors that predict cognitive outcomes could help clinicians stratify risk, guide preoperative counseling, and inform interventions to reduce the risk of postoperative cognitive decline. This systematic review aimed to identify, synthesize, and critically evaluate research on presurgical predictors of cognitive outcomes following brain tumor resection. Methods Five databases were searched from inception to April 2025. Studies were included if they examined presurgical predictors of postoperative cognitive outcomes in adults undergoing surgery to remove a primary brain tumor, using multivariate analysis. Risk of bias was assessed using the Quality In Prognosis Studies tool. Results Fifteen studies met inclusion criteria. Higher baseline preoperative cognitive performance consistently predicted better postoperative outcomes, including stability or improvement in processing speed, executive function, memory, and visuospatial skills. In comparison, sociodemographic factors and tumor related characteristics were less reliable predictors. Modifiable presurgical predictors were largely unexplored. Methodological heterogeneity limited direct comparisons across studies, underscoring the need for standardized approaches to assessing cognition in neuro-oncology research. Conclusion The review emphasizes the importance of incorporating baseline cognitive assessments into routine clinical care to help identify patients most vulnerable to cognitive decline. Future research should focus on identifying modifiable factors to prevent cognitive decline, and until then, developing interventions to reduce the impact of cognitive decline on recovery and quality of life is crucial.