the word concussion voc's a fear these
days more so than it ever has and I know
this personally I played 10 years of
football was struck on the head
thousands of times and I have to tell
you though what was much worse than that
was a pair of bike accidents I had where
I suffered concussions and I'm still
dealing with the effects of the most
recent one today as I stand in front of
you
there is a fear around concussion that
does have some evidence behind it there
is information that a repeated history
of concussion can lead to early dementia
such as Alzheimer's and chronic
traumatic encephalopathy that was the
subject of the Will Smith movie
concussion and so everybody is caught up
in football and what they see in the
military but you may not know that bike
riding is the leading cause of
concussion for kids sports related
concussion that is and so another thing
that I should tell you that you may not
know is that the helmets that are worn
and bicycling in football and many
activities they're not designed or
tested for how well they can protect
your children against concussion and
they're in fact designed and tested for
their ability to protect against skull
fracture and so I get this question all
the time from parents and they ask me
would you let your own child play
football or should I let my child play
soccer and I think that as a field were
a long way from giving an answer with
any kind of confidence there so I look
at that question from a bit of a
different lens and I want to know how
can we prevent concussion is that even
possible and most experts think that
it's not but the work that we're doing
in my lab is starting to reveal more of
the details around concussion
so that we can have a better
understanding the reason we're able to
prevent skull fracture with helmets is
because it's pretty simple we know how
it works concussions been much more of a
mystery so to give you a sense of what
might be having concussion I want to
show you the video here that you see
when you type in to Google what is a
concussion the CDC website comes up and
this video essentially tells the whole
story what you see is the head moves
forward the brain lags behind then the
brain catches up and smashes into the
skull it rebounds off the skull and then
proceeds to run into the other side of
the skull and what you'll notice is
highlighted in this video from the CDC
which I'll note was funded by the NFL is
that the outer surfaces of the brain
where was to have smashed into the skull
looks like it's been damaged or injured
so it's on the outer surface of the
brain and what I'd like to do with this
video is to tell you that there are some
aspects that are probably right
indicative of what the scientists think
happens in concussion but there's
probably more that's wrong with this
video so one thing I do agree with and I
think most experts would is that the
brain does have this dynamics it does
lag behind the skull and then catch up
and move back and forth and Asli that
that we think is true however the amount
of motion you see in the brain in this
video is probably not right at all
there's very little room in the cranial
vault only a few millimeters and it's
filled entirely with cerebral spinal
fluid which acts as a protective layer
and so the brain as a whole probably
moves very little inside the skull the
other problem with this video is that
the brain is shown as a kind of rigid
hole as it moves around and that's not
true either your brain is one of the
softest substances in your body and you
can think of it kind of like jello so as
your head is moving back and forth your
brain is twisting and turning and
contorting and the tissue is getting
stretched and so most experts I think
would agree that concussion is not
likely to be something that's happening
on this outer surface of the brain
but rather it's something that's much
deeper towards the center of the brain
now the way that we're approaching this
problem to try to understand the
mechanism cushon and to figure out if we
can prevent it is we are using a device
like this it's a mouth guard it has
sensors in it that are essentially the
same that are in your cell phone
accelerometers gyroscopes and when
someone is struck in the head it can
tell you how their head moved at
thousand samples per second the
principle behind the mouth guard is this
it fits on your teeth your teeth are one
of the hardest substances in your body
so it rigidly couples to your skull and
gives you the most precise possible
measurement of how the skull moves
people have tried other approaches with
helmets we've looked at other sensors
that go on your skin and they all simply
move around too much and so we found
that this is the only reliable way to
take a good measurement so now that
we've got this device we can go beyond
studying cadavers because you can only
learn so much about concussion from
studying a cadaver and we want to learn
and study live humans so where can we
find a group of willing volunteers to go
out and smash their heads into each
other on a regular basis distinct cushon
well I was one of them and it's your
local friendly Stanford football team so
this is our laboratory and I want to
show you the first concussion that we
measured with this device one of the
things that I should point out is the
device has this gyroscope in it and that
allows you to measure the rotation of
the head most experts think that that's
the critical factor that might start to
tell us what is happening in concussion
so please watch this video
with the news all right
justice in a post drop
separation safety
here this
by Chase sorry three times is probably
but you get the idea so when you look at
just the film here pretty much the only
thing you can see is he got hit really
hard and he was hurt but when we extract
the data out of the mouth guard that he
was wearing we can see much more detail
much richer information and one of the
things that we noticed here is that he
was struck in the lower left side of his
face mask and so that did something
first it was a little counterintuitive
his left his head did not move to the
right in fact it rotated first to the
left then as the neck began to compress
the force of the blow cause it to whip
back to the right so this left right
motion was sort of a whiplash type
phenomenon and then we think that is
probably what led to the brain injury
now this device is only limited in such
that it can measure the skull motion but
what we really want to know is what's
happening inside of the brain so we
collaborate with spine Clive ins group
in Sweden they've developed a finite
element model of the brain and so this
is a simulation using the data from our
mouth guard from the injury I just
showed you and what you see is the brain
this is a cross-section right in the
front of the brain twisting and
contorting as I mentioned so you can see
this doesn't look a lot like the CDC
video now the colors that you're looking
at are how much the brain tissue is
being stretched and so the red is 50%
that means the brain has been stretched
to 50% its original length the tissue in
that particular area and the main thing
I want to draw your attention to is this
red spot so the red spot is very close
to the centre of the brain and
relatively speaking you don't see a lot
of colors like that on the exterior
surface as the CDC video showed now to
explain a little more detail about how
we think concussion it might be
happening one thing I should mention is
that we and others have observed that a
concussion is more likely when you're
struck and your head rotates in this
direction this is more common in sports
like football but this seems to be more
dangerous so what might be happening
there well one thing that you'll notice
in the human brain that is
different than other animals is we have
these two very large lobes we have the
right brain and the left brain and the
key thing to notice in this figure here
is that right down the center of the
right brain in the left brain there's a
large fissure that goes deep into the
brain and in that fissure which you
can't see in this image you have to
trust me
there is a fiber sheet of tissue it's
called the falx and it runs from the
front of your head all the way to the
back of your head and it's quite stiff
and so what that allows for is when
you're struck and and your head rotates
in this left right direction forces can
rapidly transmit right down to the
center of your brain now what's there at
the bottom of this fissure it's the
wiring of your brain and in fact this
red bundle here at the bottom of that
fissure is the single largest fiber
bundle that is the wiring that connects
the right and left sides of your brain
it's called the corpus callosum and we
think that this might be one of the most
common mechanisms of concussion and that
as the forces move down they strike the
corpus callosum it causes a dissociation
between your right and your left brain
and could explain some of the symptoms
of concussion this finding is also
consistent of what we've seen in this
brain disease that I mentioned chronic
traumatic encephalopathy so this is an
image of a middle-aged ex professional
football player and the thing that I
want to point out is if you look at the
corpus callosum and I'll page back here
so you can see the size of normal corpus
callosum and the size of the person here
who has chronic traumatic encephalopathy
it is greatly atrophied and the same
goes for all of the space and the
ventricles these ventricles are much
larger and so all of this tissue near
the centre of the brain is died off over
time so what we're learning is indeed
consistent now there is some good news
here and and I hope to give you a sense
of hope by the end of this talk that one
of the things that we've noticed
specifically about this mechanism injury
is although there's a rapid transmission
of the forces down this fissure it still
takes a defined amount of time
and what we think is that if we can slow
the head down just enough so that it
doesn't the brain does not lag behind
the skull but instead it moves in
synchrony with the skull then we might
be able to prevent this mechanism
concussion so how can we slow the head
down a jut a gigantic helmet so with
more space you have more time and this
is a bit of a joke but some of you may
have seen this this is bubble soccer and
it's a real sport in fact I saw some
young adults playing this sport down the
street from my house the other day and
as far as I know they've been no
reported concussions but it in all
seriousness this principle does work but
this has gone too far this isn't
something that's practical for bike
riding or playing football and and so we
are collaborating with a company in
Sweden called hosting some of you may
have seen their work and they're using
the same principle of air to give you
some extra space to prevent concussion
kids don't try this at home please
this stuntman does not have a helmet he
instead has a neck collar and this neck
collar has sensors in it the same
sensors that are same type of sensors
anyway that inner mouth guard and it's a
text when he's likely to have a fall and
there's an airbag that explodes and
triggers the same way that an airbag
works in your car essentially and in the
experiments that we've done in my lab
with their device we found that it can
greatly reduce the risk of concussion
some scenarios compared to a normal
bicycle helmet so it's a pretty exciting
development but in order for us to
actually realize the benefits of
technology that can prevent concussion
it needs to meet regulations that's a
reality and this device is for sale in
Europe but is not for sale in the US and
probably won't be anytime soon so I
wanted to tell you why there's some good
reasons and then there are some
not-so-good reasons bike helmets are
federally regulated the Consumer Product
Safety Commission has been given
jurisdiction to approve
helmet for sale and this is the test
they use this is back to what I was
telling you in the beginning to talk
about skull fracture that's what this
test is for and that's an important
thing to do it can save your life and
but it's not sufficient I would say so
for example one thing this test doesn't
evaluate is it doesn't tell you is that
airbag gonna trigger at the right time
in place and not trigger when it doesn't
need to similarly it's not going to tell
you is this helmet likely to prevent
concussion or not and if you look at
football helmets which aren't regulated
they still have a very similar test I'm
not regulated by the government anyway
they have an industry body which is the
way most industries work but this
industry body I can tell you it's been
quite resistant to updating their
standards so in my lab we are working on
not only the mechanism of concussion but
we want to understand how can we have
better test standards and we hope that
the government's can use this type of
information to encourage innovation by
letting consumers know how protected are
you with a given helmet and I want to
bring this back finally to the original
question I asked which is would I feel
comfortable letting my child play
football or ride a bicycle and this is
might be just a result of my own
traumatic experience I'm much more
nervous about my daughter Rose riding a
bicycle
so she's a year and a half old and she's
already well wants to anyway race down
the streets of San Francisco this is at
the bottom of one of these streets and
so my personal goal is to and I believe
this is possible is to further develop
these technologies and in fact we're
working on something in my lab in
particular that really makes optimal use
of the given space of a helmet and I am
confident that we will be able to before
she's ready to ride a two-wheeler have
something available that can in fact
really reduce the risk of concussion and
comply with regulatory bodies and so
what I'd like to do and I know that this
is for some of you as more immediate
nature I've got a couple years here is
to be able to tell parents and
grandparents when I'm asked it is safe
and healthy for your children to engage
in these activities and I'm very
fortunate to have a wonderful team
at Stanford that's working hard on this
so I hope to come back in a few years
with with with the final story but for
now I will tell you that please don't
just be afraid when you hear the word
concussion there is hope thank you