COVID-19's Clinical-Pathological Evidence in Relation to Its Repercussion on the Central and Peripheral Nervous System.

Introduction: Although respiratory symptoms predominate in the disease caused by the SARS-Cov-2, the new coronavirus, the related neurological implications increase with numbers of new infected, requiring new tools and sufficient medical apparatus to improve the patients' prognosis. The purpose of this publication is based on the need to clarify the pathophysiological process of COVID-19 from a neurological perspective. The present study aims to review and describe the main neurological aspects associated with SARS-CoV-2, in addition to presenting proposals for conducting and managing these issues.

Methods: The MEDLINE (through PubMed) and Scopus databases were used for systematic research on the correlation between COVID-19 and the nervous system. The reference period were publications between May 2005 and July 2020. The temporal delimitation was based on the objective of elucidating the pathophysiology of neurological involvement seen in the current pandemic. Thus, in 2005, we found articles that reported different etiologies and mechanisms of action of the antiphospholipid syndrome, which helped to understand its current association with COVID-19. Other articles from years prior to the current one contributed, in the same sense of linking, with description of associated processes, in articles from 2020, the SARS-CoV-2 infection. The processes described in times before 2020 and currently correlated with cerebral dysfunction of COVID-19 were distribution of angiotensin II receptors in the brain, inflammation associated with the blood-brain barrier imbalance, and brain barrier function. "SARS-CoV-2 and complications," "neurology," "pathogeny of COVID-19," "stroke," and "encephalopathy" were terms included in the research. The relevance of the articles found was based on congruence with the search terms and on availability of the full text.

Results: Recent articles published reported mild neurological symptoms, with, for example, headache and anosmia as part of the set of common symptoms of COVID-19, highlighting the causal link between the disease and neurological complications that may exist during its evolution. It is still unknown whether the neurological clinical expression concomitant with the new coronavirus infection is a consequence or a coincidence. In order to properly treat and monitor these patients from the neurological point of view, it is essential, in times of pandemics, to suspect primary infection by SARS-Cov-2 and diagnose it to proceed with isolation and clinical support.

Conclusion: The neurological implications of COVID-19 range from initial symptoms, such as headache, to serious complications, such as ischemic stroke. Although the pathogenesis of neurological phenomena requires further studies, targeted management of the patient is feasible, considering agility in recognizing the infection. Therefore, medical precaution and clinical reasoning are emphasized when providing services to the patient.