Investigating Viral Entry Routes and the Impact of SARS-CoV-2 on the Central Nervous System

Abstract

Despite initially being thought to solely affect the respiratory tract, it is becoming increasingly evident that SARS-CoV-2 affects both the respiratory tract and the CNS. To address the relative deficit of information about this phenomenon, we reviewed several articles relating to the possible mechanisms of CNS viral invasion and the subsequent effects. The 4 review and 4 research articles analyzed in this review were obtained from PubMed using the keywords COVID-19, SARS-CoV-2, and CNS. Multiplexed bead assay for cytokine profiling, virus titration, and de-identified electronic health records (EHR) data analysis were used to obtain the results discussed in this review. The virus titration results showed that direct SARS-CoV-2 invasion into the CNS was rarely based on replication efficiency analysis. However, additional data showed that antiviral cytokines are induced by SARS-CoV-2. The results indicated that cytokine storms and their corresponding neuroinflammation may be the primary cause of neurological symptoms. After analyzing EHR data related to specific CNS symptoms, we observed that the severity of early CNS symptoms was indicative of the severity of COVID-19. We concluded that targeting the cytokine storm triggered by infection may be an ideal target of treatment in patients with severe neurological symptoms. Furthermore, by analyzing early CNS symptoms on a case-by-case basis, treatment could be tailored to be more efficient for patients, rather than approaching all infections with a similar holistic approach.