WEDNESDAY,APRIL8,2020| THEGLOBEANDMAIL O NEWS | A1 1
While the new coronavirus is known to cause
respiratory illness, some scientists suggest it
can also potentially lead to brain and nerve
damage in certain patients.
Beyond the typical symptoms of CO-
VID-19, including fever, cough and difficulty
breathing, doctors around the world have re-
ported cases of infected patients with an ar-
ray of neurological problems, including
stroke, seizures, anosmia, or a loss of smell,
and encephalopathy, a broad term used to
describe brain damage or dysfunction.
Since these reports have so far been limit-
ed to anecdotal case studies, it is still too
early to know whether the virus is to blame
for these neurological symptoms, said clin-
ical epidemiologist Jose Tellez-Zenteno,a
professor of neurology at the University of
Saskatchewan. Nevertheless, he said, it’s im-
portant for the public and health-care pro-
viders to know this is a possibility.
“The virus can go to the brain potentially,”
Dr. Tellez-Zenteno said. “And not only for
neurologists, but for [front-line] doctors ...
they have to be aware that neurological com-
plications can happen and be ready to diag-
nose and ready to treat, if there is some treat-
ment for them.”
He noted that in one study of 214 hospital-
ized COVID-19 patients in Wuhan, China, re-
searchers reported more than 35 per cent had
neurological complications, including de-
creased levels of consciousness, stroke and
muscle damage. These were more likely to
occur among the hospitalized patients who
were severely ill with COVID-19.
Dr. Tellez-Zenteno emphasized that the
vast majority of individuals who catch CO-
VID-19 have mild or no symptoms.
But the fact that many infected people ex-
perience anosmia may point to one of the
potential ways in which the virus could affect
the brain. In research on mice, the new coro-
navirus has been shown to enter the brain
from the nose through the olfactory system,
said Avindra Nath, clinical director of the U.S.
National Institute of Neurological Disorders
and Stroke, and chief of the section of infec-
tions of the nervous system.
In humans, it’s possible that the virus
merely causes damage to olfactory nerve
endings, which for many may result in noth-
ing more serious than a temporary loss of
smell, he said.
“The other possibility is that may bea
route of entry into the brain,” he said.
Dr. Nath said it would be useful to follow
up with these patients, long after they have
recovered from the viral infection, to see
whether they develop signs of lasting neur-
ological effects.
In a recent paper, published in the journal
Neurology, he also raised the question of
whether respiratory symptoms from CO-
VID-19 could arise from damage to the brain
stem, which controls breathing.
While it’s often assumed that people de-
velop neurological complications from hy-
poxia, or a lack of oxygen, when an illness
damages the lungs or other organs, it’s pos-
sible that the reverse may occur, Dr. Nath
said.
“We really need to think that some of
these patients [with respiratory syndrome]
might have primary neurological involve-
ment, and we should do CT scans or MRI
scans on them” when possible, he said.
Chronic neurological problems have been
tied to other types of coronaviruses in the
past, said Mady Hornig, associate professor
of epidemiology at Columbia University’s
Mailman School of Public Health. She said,
for example, that there have been reported
cases of myalgic encephalomyelitis/chronic
fatigue syndrome (ME/CFS), a debilitating
condition, in some individuals who have had
SARS and MERS (Middle East Respiratory
Syndrome).
“That’s one of the questions here,” Dr.
Hornig said. “We must really look hard, par-
ticularly with these types of coronaviruses,
for chronic effects that are in the neurolog-
ical – and even bordering on neuropsychia-
tric – category.”
In explaining other potential ways in
which the virus could enter the brain and
cause damage, psychoneuroimmunology ex-
pert Boris Sakic at McMaster University said
that normally, our brains are protected by
the blood-brain barrier, the densely packed
cells around the blood vessels of the brain
that prevents pathogens from entering.
However, in a “cytokine storm,” or a severe
immune reaction in certain individuals, the
blood-brain barrier can become permeable.
When this happens, viruses circulating in
the blood can then enter the brain, along
with other immune cells, or white blood
cells, that normally reside in the body, he
said. The presence of viruses in the brain
then triggers activation of the brain’s im-
mune cells, such as microglial cells, which
can produce certain toxic substances, said
Dr. Sakic, an associate professor of psychiatry
and neurobehavioural sciences.
But generally, when it comes to viral in-
fections, he said, the biggest cause of damage
to the brain is from the other white blood
cells entering the brain through the blood-
brain barrier, which cause “collateral dam-
age.”
“Let’s say you want to kill the virus, but
you also kill all the neighbouring neurons,”
he said.Scientistswarn
coronaviruscould
leadtoneurological
complications
insomepatients
WENCYLEUNGHEALTHREPORTERsamples. The proteins were purified by
University of Toronto biochemist James Ri-
ni, who specializes in coronaviruses.
Dr. Gingras said she hopes the robotic
system will be used first in a cohort study
of Toronto area health-care workers orga-
nized by the University Health Network.
Known as the RESPECT study, the goal of
the project is to detect asymptomatic cases
of COVID-19 among a population of about
3,000 health workers, many of whom are
highly likely to have been exposed to the
virus.
Deepali Kumar, a clinician with the To-
ronto General Hospital Research Institute,
said the serological testing would add valu-
able data to the study, and potentially pro-
vide some assurance to those who are
wondering if they are at risk of contracting
the virus.
“I think if we could tell health-care
workers that they have antibodies and so
have already been exposed, it might give
some peace of mind that they won’t bring
home a virus to their families,” Dr. Kumar
said.Dr.Gingrassaidshe
hopestherobotic
systemwillbeused
firstinacohort
studyofToronto
areahealth-care
workersorganized
bytheUniversity
HealthNetwork.protect front-line medical workers who
have significantly greater chance of infec-
tion.
Richard Carl, who recovered from CO-
VID-19 after contracting it while on a ski
trip in Colorado in February, said he will be
a donor.
Mr. Carl did not require hospitalization,
but was treated at Sunnybrook Hospital in
Toronto. He was cleared of the virus on
March 25, and as this study came together
last week, he was nominated to its adviso-
ry board as the patient representative.
“There is a real feeling of helplessness in
the world today,” Mr. Carl said from his
home in Toronto. “The thought of asking
someone to help fix this thing – I couldn’t
say yes fast enough.”
Mr. Carl said he hopes others who have
recovered from the virus will come out in
larger numbers to donate plasma.
“We’re going to need blood, and those
who have been infected, like me, need to
join us in this,” he said. “We need to help
fight this, and also help these front-line
health-care workers – they are putting
themselves in harm’s way to save lives.”
Using convalescent plasma to battle a
virus isn’t a new discovery, Dr. Arnold said,
adding doctors first discovered this ther-
apy at the end of the 1918-19 Spanish flu
pandemic.
“There’s nothing 21st century about this- this is so old school,” he said.
SpecialtoTheGlobeandMailThestudy,whichwill
involve1,
patientsfromacross
thecountry,will
includeatleast
Canadianhospitals.