Cerebrospinal fluid cytochemical analysis from COVID-19 patients with neurological disorders

Background The COVID-19 pandemic caused by SARS-CoV-2 has affected millions of people worldwide. Most cytochemical studies of cerebrospinal fluid (CSF) in SARS-CoV-2-infected patients show abnormal results. We aimed to determine the physical, cytological, and chemical alterations in CSF from COVID-19 patients with neurological disorders in Peru. Methods An observational, cross-sectional study was conducted at the Hospital Edgardo Rebagliati Martins. Of 94 CSF samples obtained by lumbar puncture from inpatients, 30 from COVID-19 patients with neurological disorders were analyzed. Paired t-test and one-way ANOVA with Bonferroni post-hoc test were used to compare CSF biochemical markers. Results The most frequent neurological disorders were encephalopathy (43%) and brain tumor (23%). Cloudy and reddish fluids occurred in brain tumor and intracerebral hemorrhage; transparent fluids predominated in encephalopathy. CSF glucose >70 mg/dL occurred in 30% of encephalopathy and 13% of intracerebral hemorrhage patients. Proteins >45 mg/dL occurred in 20% of encephalopathy, 17% of intracerebral hemorrhage, and 13% of brain tumor patients. No differences were found in glucose concentration between neurological disorders (p > 0.05); however, protein concentration differed (p = 0.001). Leukocyte counts <5 cells/μL occurred in 33% of encephalopathy and 20% of brain tumor patients. Conclusion These findings suggest that the CSF characteristics may differ by neurological complication in COVID-19. However, patterns were nonspecific and may reflect underlying disorders, systemic inflammation, or blood-CSF barrier dysfunction rather than direct SARS-CoV-2 neuroinvasion. Early recognition and CSF evaluation may aid clinical diagnostic and therapeutic decisions, but further prospective, multicenter, longitudinal studies, including long COVID cohorts, are still needed.