Perioperative Neurocognitive Disorder in Individuals with a History of Traumatic Brain Injury: Protocol for a Systematic Review and Meta-Analysis

Postoperative neurocognitive disorder (PND) is a cognitive decline after general anesthesia and surgery, influenced by preexisting neurodegenerative conditions, stress, and inflammation. Traumatic brain injury (TBI) is linked to a dysregulated stress response, neuroinflammation, and cognitive issues. Patients with TBI often need extracranial surgeries under general anesthesia (GA), which can increase stress, neuroinflammation, and neurodegenerative changes, raising PND risk. We will search databases like Ovid Medline and Embase for studies on cognitive function in patients with mild to moderate TBI who had extracranial surgeries under general anesthesia (GA). Screening and data extraction will be done manually and with AI-assisted tools (ASReview). Study quality will be assessed using the Newcastle-Ottawa Scale. Statistical analyses will include mean differences, odds ratios, and meta-regression, addressing heterogeneity, sensitivity, and publication bias using Stata/SE. By meta-analyzing clinical studies, we aim to determine if TBI and GA/surgery interact to induce PND. We will use various data sources, subgroup analyses, sensitivity analyses, and meta-regression to assess factors like age, gender, and type of GA/surgery. This meta-analysis will enhance our understanding of PND risks, inform clinical practices, and highlight new research directions. The systematic review is registered in PROSPERO (CRD42024510980).