Post-COVID-19 cognitive impairments (literature review)

Post-COVID-19 condition (PCC) is a condition that occurs in patients with a history of SARS-CoV-2 infection 3 months after the onset of COVID-19 with symptoms that last at least 2 months and are not explained by any other diseases. PCC affects from 17 % to 28 % of patients and includes a wide range of clinical manifestations, including cognitive dysfunction. Cognitive dysfunctions can be manifested by a wide range of symptoms, such as memory impairment, attention deficit, executive dysfunction, and reduced information processing speed. Risk factors for developing PCC, with or without cognitive impairment, include late adulthood, pre-existing medical conditions, and severity of acute illness. The underlying mechanisms remain unclear, but suspected factors include neuroinflammation, hypoxia, vascular damage and latent reactivation of the virus, this does not exclude the possibility of direct viral central nervous system invasion. The analysis of retrospective cohort studies showed that the risk of cognitive deficits, dementia, psychotic disorders and seizures remained elevated even 2 years after the infection of SARS-CoV-2. It is interesting to note that there were no differences in the risks of neurological and psychiatric outcomes between infections caused by Omicron (B.1.1.529) or Delta (B.1.617.2) variants. Recent researches show that cognitive deficits after infection of SARS-CoV-2 persist for two years after the infection and were the greatest in individuals with more severe SARS-CoV-2 infection [2].  COVID-19 can impair the function of the interoceptive network of the brain selectively, while exteroceptive brain processing remains undamaged [3].