Neuroinvasion and neurological complications in COVID-19

Abstract

Background. Coronavirus disease (COVID-19) affects not only the alveoli but also the central nervous system. The pathogenesis of neurological complications of COVID-19 is based on the receptor damage, cytokine-mediated injury, damage of the nervous system due to hypoxia, and neuronal damage due to the retrograde transport of the virus through nerve fibers.
 Objective. To determine the mechanisms of coronavirus neuroinvasion and treatment of neurological complications COVID-19.
 Materials and methods. Analysis of literature sources and own research on this topic.
 Results and discussion. In 3 days after infection viral antigens are detected in the olfactory sensory neurons of the nasal cavity epithelium, which confirms the transnasal invasion of coronaviruses. According to various authors, 36.4-84 % of patients with COVID-19 have neurological manifestations. In general, neurological symptoms of COVID-19 can be divided into three categories: symptoms of the central nervous system disorders (headache, dizziness, consciousness disorders, nausea and vomiting, ataxia, acute cerebrovascular disease, and epilepsy), symptoms of the peripheral nervous system disorders (hypogeusia, hyposmia, hypopsia, and neuralgia) and musculoskeletal symptoms. As viral infections cause cytokine storm, inflammation and hyperactive oxidation, it is advisable to use antioxidants in their treatment. According to the Japanese clinical guidelines for the treatment of acute respiratory distress syndrome, edaravone may be used as a free radical scavenger in such patients. In the experiment, edaravone reduced the area of infarction and promoted functional recovery in cerebral thrombosis. Other properties of edaravone include the prevention of excessive permeability of the pulmonary vessels’ endothelium. Own research has shown that edaravone (Ksavron, “Yuria-Pharm”) reduces the severity of inflammation and mortality in patients with COVID-19. In the control group, the level of the proinflammatory mediator interleukin-6 exceeded the upper limit of normal values by 1652.40 %, and in the Ksavron group – only by 269.97 %. Mortality in the control group was 14.3 %, and in the Ksavron group – 0 %.
 Conclusions. 1. Coronaviruses affect not only the lungs but also the nervous system. 2. Neurological symptoms of COVID-19 include headache, dizziness, consciousness disorders, nausea and vomiting, ataxia, acute cerebrovascular disease, hypogeusia, hyposmia, hypopsia, neuralgia, and musculoskeletal symptoms. 3. Edaravone (Ksavron) reduces the severity of inflammation and has an antioxidant effect, which justifies its use in COVID-19.