Newsweek - USA (2021-02-19)

NEWSWEEK.COM 29

brain to swell up “almost like a sponge put in water.”

“That in itself is a problem because that allows

things that are not supposed to go into the brain

and the blood to actually get in, and that can

set up problems in terms of the function of the

brain tissue,” Koroshetz says. “It also brings in an

inflammatory response to kind of sop up the in-

jury or sop up the proteins that are getting in that

shouldn’t be there.”

In addition to pathogens, this breakdown can

allow the unchecked infiltration of white blood

cells, which Koroshetz describes as the “tanks” of

the immune system, because they attack infected

areas with far more firepower and far less specific-

ity than the COVID-specific antibodies, which are

the “guided missiles” of the immune arsenal.

The process of verifying these hypotheses, and

myriad others to emerge from the study of the dis-

ease, is only just beginning.

Indirect attacks may account for the cellular

damage to brain tissue seen in autopsies. By some

estimates, the human body is lined with 60,000

miles of blood vessels, and ACE2 receptors, which

SARS-CoV-2’s spike proteins target, are ubiquitous

on the “endothelial” cells that line the outer surface

of these blood vessels.

“The brain,” notes NINDS’ Koroshetz, “is the most

vascularized organ in the body. It’s basically like a

gigantic complicated tangle of blood vessels.”

Destruction of the outer lining of tiny capillaries

in the brain, which has been spotted in a number of

autopsies, could break down the blood-brain barrier,

cause leakage, lead to blood clots and cause the whole

More Work to Do

de erausquin and other brain specialists like

him have been largely unable to get people to listen

to their concerns and pony up the money needed

to answer what they see a series of urgent ques-

tions. These entail not only the long-term effects

COVID-19 will have on the brains of survivors, but

also to what extent chronic neurological symptoms

will add to the burden the world’s rapidly aging

population is already expected to have on health-

care systems in the decades ahead.

That may be changing. In recent weeks, the media

has turned the spotlight onto COVID-19 long haulers

and the strange neurological symptoms that persist

HEAD CASES

The lingering effects of

COVID-19, scientists

fear, will feed a spike

in dementia and other

neurodegenerative

diseases in the decades

ahead. Above: A model

of SARS-CoV-2, with

spike proteins. Left:

A doctor in Nancy,

France, administers

an olfactory test.

“The realization that there’s a neurological

effect has been really recent. Patients

have been complaining about it for

months, but the scientists were not doing

anything about it.” — dr. avindra nath

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