Peripheral inflammation and neurocognitive impairment: correlations, underlying mechanisms, and therapeutic implications

Abstract

Cognitive impairments, such as learning and memory deficits, may occur in susceptible populations including the elderly and patients who are chronically ill or have experienced stressful events, including surgery, infection, and trauma. Accumulating lines of evidence suggested that peripheral inflammation featured by the recruitment of peripheral immune cells and the release of pro-inflammatory cytokines may be activated during aging and these conditions, participating in peripheral immune system-brain communication. Lots of progress has been achieved in deciphering the core bridging mechanism connecting peripheral inflammation and cognitive impairments, which may be helpful in developing early diagnosis, prognosis evaluation, and prevention methods based on peripheral blood circulation system sampling and intervention. In this review, we summarized the evolving evidence on the prevalence of peripheral inflammation-associated neurocognitive impairments and discussed the research advances in the underlying mechanisms. We also highlighted the prevention and treatment strategies against peripheral inflammation-associated cognitive dysfunction.

Association of peripheral B cells and delirium: combined single-cell sequencing and Mendelian randomization analysis

“…It has been demonstrated in a large number of studies that proinflammatory cytokines or chemokines are involved in the development of neurocognitive impairment due to peripheral inflammation ( 16 ). B cells may exert immunoinflammatory facilitating or modulating roles through these related cytokines.…”

“…However, there is no clarity regarding the specific mechanisms by which peripheral inflammation leads to delirium. Peripheral effector cells activated during inflammatory stress events as well as transcriptional changes in cytokines and chemokines may be involved in the above process ( 16 ). This process may be associated with the induction of neuroinflammation by circulating immune cells and pro-inflammatory mediators through invasion and entry into the damaged blood–brain barrier (BBB) ( 17 ).…”

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

“…The nervous and immune systems engage in complex communication, which is regulated by multiple mechanisms. This interaction can be disrupted by various triggers such as infections, autoimmune diseases, peripheral and systemic inflammation, traumatic brain injuries, environmental toxins, and stress, potentially leading to neuroinflammation [363][364][365][366][367][368][369][370][371][372][373][374][375].…”

Effects of electroacupuncture on postoperative cognitive dysfunction and its underlying mechanisms: a literature review of rodent studies

“…Additionally, older patients with POCD have a greater risk of developing dementia or experiencing a decline in their cognitive trajectory ( Nemeth et al, 2017 ). Elderly patients undergoing hip fracture surgery have increased neurocognitive dysfunction during the awakening period and hospitalization ( Sulaiman et al, 2014 ; Tan et al, 2023 ). Moreover, an early multicenter study investigated changes in cognitive performance after abdominal and orthopedic surgery in 1,218 elderly patients, with delayed neurocognitive recovery diagnosed in 25.8% of patients ( Kong et al, 2022 ).…”