At the end of 2019, the first cases of the coronavirus disease COVID-19 were reported from Wuhan, China (World Health Organization). The disease quickly spread around the world and when March of 2021 came around, it was declared a global pandemic. As the disease started to spread more and more quickly across the world, it became crucial for people to quarantine, wear masks, and have social distance. To this day, COVID-19 is still affecting the world, and even with the vaccine, not only are people still dying, but some people end up with after effects even after recovering. The most common side effects and symptoms of COVID-19 have had to do with respiratory issues and chest pains. COVID-19 is also thought to affect the Central Nervous System (CNS).
The CNS consists of the spinal cord and the brain, and it is what controls most functions of the mind and body. In some people, response to COVID-19 has been shown to increase the risk of dementia, stroke, muscle and nerve damage, encephalitis, and vascular disorders (U.S. Department of Health and Human Services). Early in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak, it was reported that 36% of patients were hospitalized for having issues with their CNS from COVID-19 (Kanberg et al., 2020). Previously, CNS involvement was described in hospitalized patients infected with severe acute respiratory syndrome coronavirus (SARS-CoV) during the 2003 to 2004 SARS epidemic (Kanberg et al., 2020). For this reason, it is believed that the 2019 coronavirus also affects the Central Nervous System (Kanberg et al., 2019).
The present study looks to examine the impact of COVID-19 on the CNS and to test the assumption that COVID-19 is accompanied by a CNS injury (Kanberg et al., 2020). To test this assumption for CNS injury, 2 plasma biomarkers were analyzed. One is a glial fibrillary acidic protein (GFAp), which is an intermediate filament that is highly expressed in astrocytes (a group of cells with distinct characteristics that differ within specific areas of the brain (Siracusa et al., 2022)) and serves as a marker of astrocytic activation/injury (Kanberg et al., 2020). The other is neurofilament light chain protein (NfL), which is a structural protein and a biomarker of neuronal injury like damage to nervous tissue (Kanberg et al., 2020).
The results of the study are as follows. Both high concentrations of GFAp and NfL were found in patients with COVID-19. Astrocytic activation/injury (GFAp measurements) could be a common feature in moderate to severe stages of COVID-19 (Kanberg et al., 2020). Neuronal injury (NfL) on the other hand, occurs later in the disease process and mainly in patients with only severe coronavirus (Kanberg et al., 2020). This means that neuronal injury occurs in more severe COVID-19 cases later, possibly after recovery (Kanberg et al., 2020). The results also show that plasma biomarkers (a biological molecule) of CNS damage are increased in patients that have COVID-19 and are associated with disease severity (Kanberg et al., 2020). In simple terms, the results are saying that COVID-19 does affect the CNS. Although this study does prove that coronavirus affects the CNS, further studies need to be done to interpret the type of CNS injury in this setting to evaluate further the service of these biomarkers in COVID-19 (Kanberg et al., 2020). With COVID-19 still going on and new variants of the disease developing, future studies should look to compare the different effects that these variants have on CNS in patients who have recovered from COVID-19.
References
World Health Organization. (n.d.). Coronavirus disease (covid-19) update. World Health Organization. Retrieved March 2, 2022, from https://www.who.int/bangladesh/emergencies/coronavirus-disease-(covid-19)-update#:~:text=On%20this%20website%20you%20can,on%2031%20December%202019
U.S. Department of Health and Human Services. (n.d.). Coronavirus and the nervous system. National Institute of Neurological Disorders and Stroke. Retrieved March 2, 2022, from https://www.ninds.nih.gov/Current-Research/Coronavirus-and-NINDS/nervous-system.
Siracusa, R., Fusco, R., & Cuzzocrea, S. (1AD, January 1). Astrocytes: Role and functions in brain pathologies. Frontiers. Retrieved March 2, 2022, from https://www.frontiersin.org/articles/10.3389/fphar.2019.01114/full
