COVID-19 direct effects on the central nervous system

ABSTRACT

This chapter focuses on the direct and observable effects of COVID-19 on Central Nervous System (CNS) structures and functions. It includes a review of the persistent symptoms caused by CNS damage during the acute infection by the viral infection, the immune/inflammatory response, and brain hypoxia. Viruses or bacteria can directly infect cells within the brain or spinal cord, infect the membranes surrounding the brain, or by establishing abscesses within the brain. There is strong evidence that COVID-19 causes several forms of long-term brain disease. Nasal obstruction during upper respiratory infections, when the nasal passages are substantially blocked, by seasonal allergies, or as a result of COVID-19, can also cause a temporary loss of smell. Strokes that increased during acute COVID-19 were primarily related to the hypercoagulable state of blood and an inflammatory effect on brain blood vessels that interfered with normal brain oxygenation. © 2023 John Wiley & Sons Ltd. All rights reserved.