The COVID-19 pandemic resulted in an increased societal and scientific awareness of the potential long-term cognitive problems patients may experience recovering from COVID-19. In critical care medicine, there is also increasing evidence of associations between other infections and persistent cognitive deficits and dementia. However, previous studies examining the relation between infections and cognitive decline lacked premorbid MRI scans. A potential explanation is that patients with infections already had more brain damage and were therefore more prone to develop cognitive decline after the infection.
The current study investigated the effects of infectious events on cognitive decline and the development of dementia and its possible structural underpinning using pre- and post-infection MRI of the brain. The research group, led by dr. Farid Abdo from the department of Intensive Care Medicine, in collaboration with the department of Neurology published their results in Critical Care Medicine, on August 23 2021.
The researchers used the dataset from the prospective observational Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort (RUN DMC) study, in which participants underwent repeated cognitive measurements and brain MRI during 9-year follow-up. Data on infectious episodes during follow-up were collected and were available from 331 patients. They found that sepsis episodes were significantly associated with an 82% increased risk to develop dementia within 10 years. This highlights sepsis as an important risk factor for the development of dementia regardless of age, baseline cognition, and pre-existent brain damage.
Given the ageing population, and the increased risk for infections during senescence, developing interventions that modulate the risk of dementia due to severe infections would be an important target. To increase the understanding of the neuroinflammatory response in patients with systemic inflammation they are currently performing follow-up prospective studies. The researchers hope that this will contribute to the development of effective treatments to reduce long-term cognitive deficits after surviving severe infections, such as COVID-19.
Peters van Ton AM, Meijer-van Leijsen EMC, Bergkamp MI, Bronkhorst EM, Pickkers P, de Leeuw FE, Tuladhar AM, Abdo WF. Risk of Dementia and Structural Brain Changes Following Nonneurological Infections During 9-Year Follow-Up. Crit Care Med. 2021 Aug 23. doi: 10.1097/CCM.0000000000005313. Epub ahead of print. PMID: 34432713. https://pubmed.ncbi.nlm.nih.gov/34432713/