Where are the stroke patients?... the apparent decrease amid the Covid-19 pandemic

Abstract

Amid the coronavirus disease 2019 (COVID-19) pan‐
demic caused by the SARS-CoV2 virus, and among the
many difficult questions we are facing day-by-day, a
rather unusual question has challenged neurologists:
Where is everybody with acute ischemic stroke?
Recently, on the popular physician site Medscape, the
question was raised whether patients with acute stroke
were not seeking emergency care, based on reports from
neurologists who reported to be experiencing an unusu‐
ally low number of patients with acute ischemic stroke
(AIS) [1]. In this commentary, we explore three poten‐
tial explanations that might help us to take advantage of
the situation and gain some insight about both entities.
The first explanation is that patients with acute stroke
are staying at home due to fear of COVID-19 contagion.
This hypothesis suggests that patients with minor AIS or
transient ischemic attacks (TIAs) do not seek attention
because of the low severity of symptoms. Although
plausible, it is not only minor strokes or TIAs that have
decreased. In our hospital, a regional reference center
that serves five states on northeastern Mexico, we have
witnessed a decreasing trend in stroke cases admitted to
the neurology ward after March 1, which also has been
reported by the weekly epidemiological bulletin from
the health ministry. A situation similar to that reported
by neurologists on Medscape, and by cardiologists in
The New York Times, who reported less patients pre‐
senting with coronary events [2], with unconfirmed
reports from New York City’s emergency responders
that at-home deaths from cardiac arrests had skyrocketed
[3].
The second explanation is that patients at risk of or with
AIS are currently admitted due to COVID-19. Both enti‐
ties share common risk factors like older age, obesity,

and hypertension; and comorbidities have been associ‐
ated with more severe illness from SARS-CoV-2 infec‐
tion [4]. Studies regarding neurological involvement in
patients admitted for COVID-19 report that AIS occurs
in less than 5% of patients [4,5]. Etiological investiga‐
tions revealed that patients developed a hypercoagulable
state without predominance of traditional etiologies
(large vessel, small vessel, or cardioembolism) [5].
However, some case series suggested that young patients
(under 50 years) might be at risk of large-vessel stroke.
[6] Although interesting, these findings must be inter‐
preted with caution, and this hypothesis would have to
be confirmed with larger studies evaluating the inci‐
dence and etiology of stroke in patients with COVID-19.
The last explanation, perhaps the most thought-provok‐
ing and the harder to prove, is that patients are indeed
having fewer strokes as a consequence of increased
hygiene measures. We hypothesize that the apparent
decrease could be a consequence of increased infection
control measures to prevent the spread of COVID-19.
Infectious diseases are known to act as a trigger for AIS,
particularly with respiratory infections having the great‐
est effect – particularly on the first few days after infec‐
tion [7]. The proposed underlying pathophysiology is
the induction of a hypercoagulable state [7], which has
already been reported in patients with COVID-19 [8],
and as the potential mechanism underlying the etiology
in COVID-19-associated stroke [5]. Prevention of infec‐
tious diseases through vaccination is recommended as a
secondary prevention measure in patients with stroke
[7]; however, there have been no trials evaluating strat‐
egies to reduce the spread of communicable diseases as
a method to prevent strokes, by preventing potential
infectious triggers.

Furthermore, the potential role of asymptomatic SARS-
CoV-2 infection as a trigger for AIS has remainedlargely ignored, given the priority of testing those with
symptoms, and the scarcity of tests in resource-limited
centers. In light of the evidence showing that many
patients with SARS-CoV-2 present with no symptoms at
all [9], and the ease of transmissibility [10] with poten‐
tial for severe complications of patients with numerous
comorbidities (as the ones found in a neurological
ward), testing of SARS-CoV2 in patients with nonres‐
piratory symptoms and stroke will likely represent an
ethical dilemma for the coming months, although uni‐
versal screening is being advocated in certain popula‐
tions [11].
Whether or not the apparent decrease in stroke incidence
is a result of increased measures implemented to contain
the spread of SARS-CoV-2 remains to be resolved. We
believe that, by addressing these issues, we could gain
some insight into how preventive measures could help
reduce the burden of not only communicable diseases
but also the burden of cerebrovascular diseases. Our
hypotheses will have to be confirmed once enough data
are available regarding the impact of COVID-19 on
other communicable diseases and, particularly, on non‐
communicable diseases. Should it be confirmed, the
decrease in the latter through infection control measures
will represent an important intervention for stroke pre‐
vention.