So I'm just going to place this in here, so please keep your eyes closed
That feels a bit weird, sort of looks like a bathing cap.
What we’re doing here is taking the science of consciousness
and building tools that we can use at the bedside to assess patients after
brain injury to have a better estimate of how
conscious they might be, even if they can't express that in their
behaviour. So you just basically are measuring activity from somebody's
brain... without making any invasive measurements, you're placing
an electrode on the skull, measuring that minor tele electrical
activity and that gives us a clue that this person might be conscious.
Dr Srivas Chennu is a neuroscientist at the University of Kent.
He has devised a technique which aims to uncover the true level of brain activity
in patients believed to be in vegetative or minimally conscious states.
Costas is a healthy subject demonstrating how the technique works.
For 10 minutes, we collect activity from 128 sensors from their brain
and then from the data we collect, we look at the pattern of connections
between brain alias, as measured by these senses
and it turns out that, in the healthy young adult brain,
the strongest connections tend to be between frontal and parietal areas – areas
of the front of the brain and the back of the brain.
And we know from a lot of neuroscience that these are the areas
that sustain consciousness in the healthy brain and
that's exactly what you see here – this mohawk as I like to call it
of connections that are strongest between those front
and back areas, those arcs indicate the strength of the connections.
If you compare that to the next image: this is of a patient
who is in a so-called vegetative state and what you see is a dramatic loss of
those connections compared to the healthy brain where
there are far fewer connections and also much weaker when they are there.
In the third image now, you can see patients who has behaviourally the same
profile as the previous patient in this patient
too, there is no evidence at the bedside that
we can measure that indicates any awareness. They score
the same on any clinical test and, for all intents and purposes,
they look like they're in a vegetative state. But if you measure the brain
activity with the technique we've just shown,
they produces rich and detailed mohawk-like connectivity that is
very similar to that seen in a healthy adult.
In the UK, there is estimated to be up to 24,000 people in a vegetative or
semi-conscious state. This means that, although at times the
patient seems awake, they have either limited
awareness or no awareness of themselves or their environment.
At present the only way medical consultants can assess brain activity in
a patient is to complete behavioral tests.
Dr Chennu's technique approaches this assessment in a new way
by assessing the brain itself. What we do know from a lot of neuroscience of
consciousness is that these brain areas – what we call
the frontal parietal cortex – they have key areas that seem to connect
with each other, that seem to be talking to each other
when people report having a sense of self, having a sense of
experiencing the fact that they are there. And what turns out to be the case
is that there are some patients in whom, though they have no evidence of behaviour,
you can see activity potentially coming from those brain
areas registering on the EEG signal.
Although he didn't really respond to anything
I knew he was there, just by looking into his eyes. I knew
my husband was there. Because he was in the low awareness state
sometimes his response is, like I would say to him ‘look at me’ and I’d move
and it could be two minutes later, three minutes later, and his eyes would move
and that's when I thought ‘he's there’. We had a telephone call at about
half past ten at night, saying that Ruth had gone into a,
well, had some sort of heart, yeah it was actually cardiac arrest.
Nobody actually said to us that Ruth would not recover.
Often the first thing they want to know is are they going to improve? Are they
going to get better? Is there anything you can do?
What can we do to make things better?
Assessing brain activity is not a new practice
but until now it has never been assessed at the bedside so easily.
A previous technique breakthrough came when patients were assessed in an MRI
machine while being asked to imagine playing
tennis. When we imagined doing some sort of
physical kinesthetic action, there's a particular bit of your brain
that lights up in an MRI scanner and that's called the supplementary
motor area. And by measuring activity there, we're
demonstrating that even if this patient can't actually play tennis,
they are well able to imagine that action
on demand, and that's why that task became really popular
as a means to assess what we would now call hidden awareness or covert
awareness that isn't expressed at the bedside. The
areas of the brain that sort of create an awareness
of one’s own self, that create an awareness of the fact that somebody’s
asking you to do something and then enable you to actually perform
that task – those are the brain areas that we’re measuring activity from
with the EEG. By doing that, what we're trying to do is assess
patients more easily. We don't have to ask them to do something
and also we can do it at the bedside, because remember
with the tennis you need an MRI scanner which is very expensive and most
patients can't go in one. And what's more, many patients
might be unable to understand instructions
because of aphasia, so damage to the language areas
so might not be able to play tennis but might still be conscious. So what we’re
trying to do with this task, the simple assessment with EEG
is to just ask them to be at rest and measure the brain
activity during that time.
Headway House is a centre for patients who have suffered from a brain injury
these patients are now free from life support interventions and are working
towards as full a recovery as possible. I went out one Christmas, went to a pub.
A friend of mine got a fibreglass sports car for Christmas.
He said: ‘If you're still here when I get back, I'll give you a lift home.’
So he came back, I suppose about 10 minutes before the pub closed. We had
one more drink and then he drove me home. My
15-minute cycle journey lasted about six months.
He, um, lost control going up a hill and hit a telegraph pole. Neither of us
wearing seat belts but they weren't obligatory then.
As I come out of the dashboard, I've caught a glance and blow on the telegraph pole
which caused all damage on the left-hand side. Got to hospital
they called in my parents. Apparently I said 'I'm very very sorry' to my parents
and then didn't know another thing for about four weeks.
During that four weeks, I had some very very interesting experiences
within my own mind. Some of the patients we see
who have what we call severe brain injury – much more severe –
don’t necessarily wake up as quickly as you have – right?
And that's a challenge. That is particularly problematic in a hospital
where doctors are trying to understand how much brain injury there is,
what chances are for recovery. So what we have tried to do
is try and understand how what we know about consciousness and the brain
tell us about how much recovery is possible, how long is it going to take?
Etc etc... It's likely that these patients are
conscious but they're not conscious in the way that
you might experience consciousness, and that's the most remarkable thing –
that you can have consciousness as you perceive it
in the absence of memory. Although that's another
interesting thing, right – do we actually exist without memory?
Very good question. This is really really philosophical -
these are hard questions. The aim of being here today is for us to first of
all understand the experiences of patients
who've been through brain injury but are now able to tell us what it was like.
But also for us to be able to explain the science to them and inform
the general public and inform patients about what’s possible.
informing the public on scientific advancements is obviously very important
as is the accurate reporting of cases which feature brain injury by the media.
The generic word 'coma' is used a lot in the media. It's nice and short for headlines –
everyone thinks they understand what a coma is. Professor Jenny Kitzinger is the
co-director of the Coma and Disorders of Consciousness Research Centre.
She has conducted a study of 2000 news reports over the last 10 years
to assess the accuracy of the language used. The term 'vegetative'
may be less likely to be used and the term 'minimally conscious'
even less likely. So the media both sensationalises this but also
promulgates confusion about these different
diagnostic categories. Vegetative state has sort of come to
sort of stick with us but is ultimately pejorative in the
sense that it is automatically implying that somebody in a vegetative state
could have no cognition – no more than a vegetable and, of course,
that's far from what we find. And hence a new term is
something clinicians and I have been proposing
should be used and that's called the 'unresponsive
wakefulness syndrome'. I do think we need to find new terminology – it's something
me and my colleagues are always talking about the world over. If
you say to a family member, 'your loved one's in a vegetative state',
what 99% of the time they hear is 'your loved one's a vegetable' And we get
that told to us numerous times by the families of our patients that
they hear 'vegetable' they don't hear 'vegetative'. It means nothing to them.
I do think there's a good reason for understanding brain activity
particularly in areas of disorder of consciousness.
We know that many people are misdiagnosed as being in a vegetative
state when actually their awareness is much higher. We know
we can miss people that are in a locked-in syndrome,
because we don't understand at the moment of the accident, or shortly after,
what activity is there? We did ask for a brain scan at one stage,
didn't we? But I didn't want to know the results.
I would be... I would like to know. I would like to know of the brain's
activities, um, because at that stage it seems to me,
um, you'd be more
aware of what is or is not possible. And I think I would like to know that.
Glass half full, glass half empty. I don't want to know what the
limitations are and I think if you want to know how far you can go forward
you've also got to be aware of what the limitations are. I don't want to know that.
you