Cerebrospinal fluid profile in coronavirus disease 2019, a prospective case series study

<b>Background:</b> Cerebrospinal fluid (CSF) analysis in patients with Coronavirus disease 2019 (COVID-19) and co-existing acute neurological involvement remains poorly understood. <b>Objective:</b> To investigate the CSF profile in patients with COVID-19 and co-existing acute neurological involvement. <b>Methods:</b> This prospective case series study included patients with confirmed severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection and co-existing acute neurological involvement who underwent lumbar puncture in two teaching hospitals between November 2022 and April 2023. Demographics, clinical characteristics, and CSF profile, including leukocyte count, total protein, and glucose levels, oligoclonal band (OCB) patterns, blood-CSF barrier function, SARS-CoV-2 mRNA, and SARS-CoV-2 antibodies were described. <b>Results:</b> A total of 26 participants were analyzed. The median age was 51 (interquartile range [IQR] 39-76) years, and 18 (69.2%) were male. The median open CSF pressure was 140mm (IQR 110-183) water column, and the median CSF total protein was slightly elevated (485 [IQR 350-611] mg/L). The most frequent pathological finding was elevated CSF total protein (12 [46.2%] samples) and blood-CSF barrier dysfunction (12 [46.2%] samples). SARS-CoV-2 was undetectable in all CSF samples using the reverse-transcriptase-polymerase-chain-reaction detection. SARS-CoV-2-IgG-antibody was positive in five CSF samples, while SARS-Cov-2 IgM antibodies were not detected in all participants. <b>Conclusions:</b> This study showed that some patients with COVID-19 and co-existing acute neurological involvement presented non-specific inflammatory CSF abnormalities despite no SARS-CoV-2 being detected in the CSF. Our findings suggest that neurological injury is related to disordered immune responses associated with systemic inflammation rather than direct virus invasion.