Stroke in patients infected by the novel coronavirus and its causal mechanisms: A narrative review

Abstract
Objective The current study aimed to evaluate the mechanisms of stroke development during the coronavirus disease 2019 (COVID‐19) pandemic and analyze the related characteristics, such as etiology, age group, associated comorbidities, and prognosis. Methods A narrative was performed using the descriptors [“novel coronavirus”] AND [“stroke”] in the PubMed, Science Direct, Google Scholar, Lilacs, and Biblioteca Virtual em Saúde (BVS) databases, including studies published between December 1, 2019, and April 28, 2020. Results A total of 142 articles were identified, with 89 of them in the PubMed database, 46 in Science Direct, and 7 in Google Scholar. No articles were found using the defined keywords in the Lilacs and BVS databases. A total of 22 articles were included for final evaluation. We observed that infection by the novel coronavirus caused a greater risk of the occurrence of stroke, with several studies suggesting etiological mechanisms, such as the involvement of angiotensin‐converting enzyme 2, viral invasion, and hypoxia as well as the increase in D‐dimer and the reduction in platelets, which had been commonly observed in COVID‐19 cases. The most common complication of stroke was found among the elderly with preexisting comorbidities, mainly cardiovascular disease. We detected reports of strokes among young people with no preexisting risk factors for thromboembolic events, in which the mechanism related to the viral infection was the most probable cause. In this review, we confirmed that stroke is part of the spectrum of clinical manifestations resulting from COVID‐19 and is associated with a worse prognosis. Cerebrovascular lesions resulting from complications of the infection by the novel coronavirus occurred as a result of ischemic, hemorrhagic, and/or thromboembolic etiologies. Conclusion The occurrence of stroke during the pandemic as a result of the novel coronavirus has a multifactorial character, and emergency physicians should focus on systematic measures for its screening and accurate diagnosis as well as on appropriate interventions based on early decisionmaking that may have a favorable impact on reducing damage and saving lives.