[Impairments in neurocognitive functions in patients with long COVID: A systematic review]

Studies have shown impairments in neurocognitive functions which persist more than 3 months after COVID-19 (long COVID). It remains unclear what these impairments entail, how long they persist and what proportion of the patients exhibit them.

To define the specific neurocognitive profile and to determine the proportion of deficits in at least one cognitive domain in patients with long COVID.

We conducted a systematic search in PubMed according to PRISMA 2020 guidelines with the following inclusion criteria: peer reviewed publications in which patients were assessed more than 3 months following acute COVID-19 by means of a test battery for different domains of neurocognition.

We found a total of 1178 papers, of which 7 cohort studies and 1 case-control study were selected. The proportion of patients having deficits in at least one domain of neurocognition ranged from 23% to 100%. Most frequent impairments were found in attention and speed of information processing, anterograde memory, working memory and executive function. Quality of the included studies was moderate.

Impairments in neurocognitive functions are highly prevalent among patients with long COVID and include various cognitive domains. We encourage further research to continue studying the complex interaction of COVID-19, neurocognitive impairments and neuropsychiatric syndromes.