Current Progress on Neuroinflammation-mediated Postoperative Cognitive Dysfunction: An Update

Abstract: Postoperative cognitive dysfunction (POCD) is a common complication of the central nervous system (CNS) in elderly patients after surgery, showing cognitive changes such as decreased learning and memory ability, impaired concentration, and even personality changes and decreased social behavior ability in severe cases. POCD may appear days or weeks after surgery and persist or even evolve into Alzheimer's disease (AD), exerting a significant impact on patients’ health. There are many risk factors for the occurrence of POCD, including age, surgical trauma, anesthesia, neurological diseases, etc. The level of circulating inflammatory markers increases with age, and elderly patients often have more risk factors for cardiovascular diseases, resulting in an increase in POCD incidence in elderly patients after stress responses such as surgical trauma and anesthesia. The current diagnostic rate of POCD is relatively low, which affects the prognosis and increases postoperative complications and mortality. The pathophysiological mechanism of POCD is still unclear, however, central nervous inflammation is thought to play a critical role in it. The current review summarizes the related studies on neuroinflammation-mediated POCD, such as the involvement of key central nervous cells such as microglia and astrocytes, proinflammatory cytokines such as TNF-α and IL-1β, inflammatory signaling pathways such as PI3K/Akt/mTOR and NF-κB. In addition, multiple predictive and diagnostic biomarkers for POCD, the risk factors, and the positive effects of anti-inflammatory therapy in the prevention and treatment of POCD have also been reviewed. The exploration of POCD pathogenesis is helpful for its early diagnosis and long-term treatment, and the intervention strategies targeting central nervous inflammation of POCD are of great significance for the prevention and treatment of POCD.