To identify cerebrospinal fluid (CSF) SARS-CoV-2 RNA, biomarkers and pro-inflammatory cytokines associated with cognitive impairment after covid-19.

Post-covid cognitive dysfunction represents a frequent and disabling manifestation of long covid, with estimated prevalence ranging from 10% to 20% of survivors. Elevated systemic inflammatory markers such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α have been reported, but their relationship with cognitive outcomes and CSF inflammatory signatures remains unclear.

Twenty patients were enrolled (50% male; mean age 45.4 ± 9.2 years; median 44.5 years). Cognitive impairment was identified in nine participants (45%). The mean time between covid-19 onset and CSF collection was 130.9 days (SD 100.4; median 103.5 days). No control group without covid-19 was included. We observed no differences in basic CSF analysis. Comparative analysis showed no significant differences in CSF biomarker or cytokine concentrations between patients with and without cognitive impairment. One patient without cognitive impairment had detectable SARS-CoV-2 RNA in the CSF, with no evidence of blood contamination. This CSF was collected 100 days after covid-19 was confirmed, and basic analysis of the material was normal.