Cerebrospinal fluid in COVID-19: A systematic review of the literature

Lewis, Ariane; Frontera, Jennifer; Placantonakis, Dimitris G.; Lighter, Jennifer; Galetta, Steven; Balcer, Laura; Melmed, Kara

OBJECTIVE: We sought to review the literature on cerebrospinal fluid (CSF) testing in patients with COVID-19 for evidence of viral neuroinvasion by SARS-CoV-2. METHODS: We performed a systematic review of Medline and Embase between December 1, 2019 and November 18, 2020 to identify case reports or series of patients who had COVID-19 diagnosed based on positive SARS-CoV-2 polymerase chain reaction (PCR) or serologic testing and had CSF testing due to a neurologic symptom. RESULTS: We identified 242 relevant documents which included 430 patients with COVID-19 who had acute neurological symptoms prompting CSF testing. Of those, 321 (75%) patients had symptoms that localized to the central nervous system (CNS). Of 303 patients whose CSF was tested for SARS-CoV-2 PCR, there were 16 (5%) whose test was positive, all of whom had symptoms that localized to the central nervous system (CNS). The majority (12/16, 75%) of these patients were admitted to the hospital because of neurological symptoms. Of 58 patients whose CSF was tested for SARS-CoV-2 antibody, 7 (12%) had positive antibodies with evidence of intrathecal synthesis, all of whom had symptoms that localized to the CNS. Of 132 patients who had oligoclonal bands evaluated, 3 (2%) had evidence of intrathecal antibody synthesis. Of 72 patients tested for autoimmune antibodies in the CSF, 4 (6%) had positive findings. CONCLUSION: Detection of SARS-CoV-2 in CSF via PCR or evaluation for intrathecal antibody synthesis appears to be rare. Most neurological complications associated with SARS- CoV-2 are unlikely to be related to direct viral neuroinvasion.