New Scientist - 29.02.2020

(Ben Green) #1
8 | New Scientist | 29 February 2020

WHEN a person sustains a severe
brain injury that leaves them
unable to communicate, their
families and doctors often have
to make life-or-death decisions
about their care for them. Now
brain scanners are being tested
in intensive care to see if mind-
reading can enable some patients
to have their say, New Scientist can
exclusively reveal.
At the moment, doctors ask
the families of people who have
a poor prognosis and cannot
communicate if they think their
relative would want to continue
life-sustaining treatments such as
being on a ventilator. “Life would
be so much easier if you could just
ask the person,” says Adrian Owen
at the University of Western
Ontario in Canada.

Owen’s team previously
developed a brain-scanning
approach for a much smaller
group of people – those in states
between consciousness and being
in a coma, for example those in a
vegetative state. Such people show
few signs of awareness and have to
be fed through a tube.
Owen found that some of these
people can direct their thoughts
in response to instructions, which
can be picked up on brain scans.
If someone is asked to imagine
playing tennis, for instance, the
part of their brain involved in
movement lights up in the scan.
This has let his and other teams
ask those who are able to respond
in this way yes/no questions,
which can give people a say over
their living conditions. About a
fifth of people the technique is
tried on can respond.
Owen is now using the same

technique on people who are in
intensive care in the first few days
after sustaining a severe brain
injury. In such circumstances, just
over a quarter of people end up
having their treatment withdrawn
due to a poor prognosis.
For example, in some cases
doctors may predict that if the
person survives, they would be
paralysed and unable to speak. “A
decision will typically be made in
the first 10 days about whether to
go on or pull the plug,” says Owen.
His team has so far used brain
scanning on about 20 such
people in intensive care to try
to communicate with them.
Owen won’t yet reveal how many
responded to questions, nor
whether he asked them if they
wanted to live or die.
But he says he has also made
progress in developing a new brain
imaging technique. The original
method uses fMRI machines.
To use them the person has to be
taken to a separate room and put
inside a scanner, and their tubes
and equipment have to be
changed to allow this to happen.
“It’s really challenging and
dangerous,” says Owen.
The new approach uses
functional near-infrared
spectroscopy, which can be

done at the bedside and requires
only a headset. Although the
method visualises only a small
part of the brain, this is enough
to let someone answer a yes/no
question by imagining playing
tennis to give the answer “yes”.
In a paper published last week,
Owen’s team showed this allowed
volunteers without brain injury to
accurately answer questions three-
quarters of the time (Frontiers in
Neuroscience, The
team has also used it successfully
to speak to people with a condition

that causes complete paralysis (see
“Temporarily locked in”, below).
As well as conveying
information about a person’s
wishes, bedside mind-reading
may also be useful for shedding
light on their prognosis. Among
people in a vegetative state, those
who can respond to instructions
in a brain scanner are more likely
to recover, says Owen.

Continued treatment
He believes the technique is
more likely to lead to ventilator
treatment being continued than
stopped. “Negative findings are
hard to interpret,” he says.
“Positive findings are easier.”
“This is potentially exciting but
I wouldn’t want people to get their
hopes up because this might only
be applicable to a very small group
of people,” says Paul Dean of the
UK’s Intensive Care Society.
If doctors are able to
communicate with people in
this way, they would have to be
confident the patient had the
legal mental capacity to make
life or death decisions, says Jenny
Kitzinger at Cardiff University,
UK. “Have they understood the
question, have they understood
the diagnosis?” ❚

“ Following a severe brain
injury, over a quarter
of people have their
treatment withdrawn”




Medical mind-reading

Doctors are using brain scanners to ask patients who cannot speak
about their treatment wishes, reveals Clare Wilson

People in intensive care
can be unable to say what
treatment they want

Brain-scanning techniques can
also help people with temporary
paralysis communicate. In
Guillain-Barré syndrome, people
may lose their ability to move
and spend a few weeks immobile
in intensive care, but they
usually recover.
Most people are sedated while
they are “locked in”, but a few
ask to remain conscious. In three
cases, at their doctors’ request,

Adrian Owen at the University
of Western Ontario in Canada
has used brain scanning to talk
with the person while they were
paralysed, to check they wanted
to remain unsedated.
“It takes 5 minutes to get
absolute confidence in their
response to each question,”
he says. “But there is no other
way to communicate with
these patients.”

Temporarily locked in

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