The Neuro-cognitive Implications of COVID-19 Infection: A Systematic Review with an Insight into the Pathophysiology (P11-13.009).

Objective: This study aimed to investigate the evidence of neuro-cognitive symptoms observed in COVID-19 patients and explore the underlying mechanisms.

Background: The COVID-19 pandemic has been affecting millions globally. Besides other presentation of long covid, evidence shows persistent cognitive impact, imposing further clinical and psychosocial challenges.

Design/methods: a systematic review that followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search in electronic databases using google scholar and pubmed from 2020 to 2023 was conducted.

Results: Out of the initial 435 studies, 111 studies investigating the neurocognitive impact of COVID-19 and its pathophysiology were examined. Several neuro-cognitive symptoms were reported; namely, executive dysfunction, memory loss, attention deficit, fatigue, anxiety, delirium, and processing speed delay. Other symptoms were also identified. The exact pathophysiological mechanism behind the cognitive effects is not clear. However, the review collected evidence that suggests several potential mechanisms. The virus may enter the central nervous system (CNS) through the olfactory nerve, vascular endothelial cells, or immune cells, breaking the blood-brain barrier by binding to the ACE2 receptor. Once in the brain, the virus can cause direct and indirect damage through various mechanisms The review yielded that the combination of direct replication, immune-related inflammation involving cytokines as IL-6, TNFα, and IL-1β, immune dysregulation, vascular changes, low oxygen, brain hypometabolism, neurotransmitter imbalances, oxidative stress and amyloid deposit are responsible of the neurocognitive implications. Interestingly, many studies showed that the cognitive impacts correlate with disease severity and psychiatric manifestations. Also, the studies emphasized the role of neuroimaging including 18F FDG PET scans (Positron Emission Tomography scans), in understanding the cognitive effects of COVID-19.

Conclusions: Neuro-cognitive sequelae of covid-19 are well documented. Although several hypotheses on the mechanism have been published, more data is needed for the extended impact of COVID-19 including the use of validated cognitive tests before and after the infections. Ms. Salih has nothing to disclose. Dr. Hassan has nothing to disclose. Dr. Ibrahim has nothing to disclose. Dr. Omer has nothing to disclose. Dr. Abdelsamad has nothing to disclose. Dr. Elmustafa has nothing to disclose. Dr. Elomeiri has nothing to disclose. Dr. Mahmoud has nothing to disclose. Dr. Ahmed has nothing to disclose. Dr. Hassan Alsamani has nothing to disclose. Dr. Abdalla has nothing to disclose. Dr. Abdelrahman has nothing to disclose.