Introduction
The coronavirus disease 2019 (COVID-19) pandemic caused by the new type
of coronavirus 2 (SARS-CoV-2) was shown to affect both the respiratory
tract and neurologic systems. The neurologic impairments that may occur
as a result of the spread of the virus to the central nervous system
through various mechanisms are headache, dizziness, impaired
consciousness, seizures, encephalitis, cerebrovascular diseases,
neuromuscular disorders, and peripheral nervous system involvement.
Neurologic symptoms can occur in more than 50% of hospitalized patients
(1).
Acute ischemic stroke (AIS) is a life-threatening complication of
COVID-19. Information on the incidence of stroke, which is an important
cause of morbidity and mortality, its association with COVID-19, and its
course in infected patients in this pandemic period is increasing.
Uncontrolled cytokine storm seen in severe disease can lead to
multi-organ failure, and the activation of the microthrombotic pathway
with destructive pathologic mechanisms mediated by the endothelial
system can cause stroke (2).
When assessing the link between COVID-19 and ischemic stroke, AIS has
been increasingly documented in younger patients with COVID-19 (3) or
patients without cardiovascular risk factors and significant
comorbidities (4). To date, the true incidence of AIS in patients with
COVID-19 remains unclear, but in a study of 214 patients in Wuhan, the
first epicenter of the pandemic, the incidence was 2.34% (5), it was
0.9% in a study in New York (6), and 1.2% in a more recent pooled
analysis that evaluated 4466 patients (7).
It is known that in the pathogenesis of SARS-CoV2, the virus enters the
cell by binding to the ACE-2 receptor. ACE-2 receptors, found in many
tissues, are also present in endothelial cells. In the course of the
disease, an increase in inflammatory markers, a deterioration in
coagulation parameters such as elevation of D-dimer and
thrombocytopenia, and an increase in blood pressure predispose to
ischemic and hemorrhagic cerebrovascular events (8). It has been
suggested that COVID-19 may induce a prothrombotic state accompanied by
high fibrinogen and D-dimer levels (9). It has also been reported in
various case series and reports that large vessel occlusion (LVO) is
more common in patients with AIS and COVID-19 (3).
Given the rapidly increasing COVID-19 prevalence and its AIS
complications globally, it is important to understand their relationship
more deeply. The literature published to date has been limited to case
reports, case series, and observational cohort studies. The number of
studies including the effect of COVID-19 on mortality and prognosis in
patients with AIS, and diagnostic and prognostic laboratory
investigations are limited. In this study, it was aimed to compare the
demographic, clinical, and stroke characteristics, neuroimaging
findings, prognosis, and mortality of patients with AIS with and without
COVID-19 admitted during the same period.