Structure and function of the blood–brain barrier in perioperative neurocognitive disorders

Background: Perioperative neurocognitive disorders (PNDs) are the most common neurological complications in elderly patients undergoing surgery. Patients with PNDs have significantly greater incidences of postoperative disability and mortality. Currently, there are no specific treatments for PNDs. Methods: This review integrates the latest evidence examining the role of structural and functional changes in the blood-brain barrier (BBB) in the pathological mechanisms of PNDs, with the aim of identifying innovative preventive strategies and promising therapeutic targets for PNDs. Results: Researchers have proposed various hypotheses to shed light on the pathogenesis of PNDs, including neuroinflammation, neurotransmitter or receptor abnormalities, beta-amyloid (Aβ) deposition and tau protein phosphorylation, oxidative stress, iron homeostasis imbalance, circadian rhythm disruption, and changes in the gut microbiota. Damage to the BBB plays a critical role in the pathogenesis of PNDs. Conclusion: This article summarizes the role of BBB structural and functional changes in the pathogenesis of PNDs reported in recent studies, with the goal of providing new ideas for preventing and treating PNDs.