Overview of Traumatic Brain Injury (TBI)


[ Music ]>>Interviewer: The Brain Injury
Guide and Resources is a tool for professionals,
community members and family to understand traumatic
brain injury as well as how to promote better living for
those who live with a TBI. In this interview, we will
talk with Dr. Christopher Wolf, a physiatrist in the
Department of Physical Medicine and Rehabilitation at the
MU School of Medicine, to learn some basic information
about traumatic brain injury. And, Chris, thanks very
much for being with us. I appreciate it.>>Dr. Wolf: I appreciate
you having me.>>Interviewer: First,
Chris, give us an overview of the structure of the
brain, if you would.>>Dr. Wolf: Well,
with the brain itself, a lot of people have seen a
lot of different pictures. This is one we’re
going to use today. But it’s a very delicate
structure. It’s — basically, what it is is
a very soft gelatinous structure that’s kind of hidden
inside the skull. And so the skull
is our protection for this very soft structure. The overall structure that you’ll see back
here is the cerebrum, which is the overall
bigger portion of the brain. Huddled underneath
it is the cerebellum. And then there’s a brain
stem that’s not actually seen on there that’s continuous
with the spinal cord itself. And those structures
kind of make up the central nervous
system with the brain kind of being the computer that
runs the whole system.>>Interviewer: What’s
the relationship of the brain structure to
the functions of the brain?>>Dr. Wolf: Well, we know
there’s definitely a connection to all the different structures and the functions
that they provide. And anyone who tells you
that we know everything about the brain doesn’t
really know about the brain, because there’s a lot more we
don’t know than what we do know. Now, with the brain, it is
broken up on this picture that we have behind us here
into the different lobes. Each lobe serves
different functions. The frontal lobe, which is a
commonly injured structure, seats a lot of judgment and
reasoning and motivation. That is a very common place
for what makes us human and what we call the
executive functions, which kind of incorporates
all that is seated there. The temporal lobe seats
a lot of our memories, and a lot of our ability
to think is in that area. And then the occipital lobe
essentially controls a lot of our visual functions
and our ability to see and helps sub-serve some of the
other functions of the brain. And then you see
that central sulcus where we have the postcentral
gyrus and the precentral gyrus, fancy terms for those
little areas of the brain. But those are going
to serve for movement and initiating movement,
being able to move your foot, move your leg, and
that sends the impulses down through the spinal cord. But, also, a different portion
of it receives information from the legs and arms and
actually allows you to feel when someone’s touching you. And so those are the ones that
you can see on the outside. But then deeper than that,
there’s another layer, and the subcortical
layers; and there’s areas such as the basal
ganglia and the cerebellum which you can just see peeking
out from underneath it kind of modify the movements
and have purposes to try to help coordinate and
make things work smoother and better than normal. And those are — those
are all then connected into the spinal cord itself.>>Interviewer: So what
happens in a brain injury?>>Dr. Wolf: Well, in a brain
injury, there’s multiple things that happen all at once. Now, we mentioned that the brain
structure itself is very soft and almost gelatinous. And there’s different areas and different densities
through the brain. So when the brain is injured,
it’s essentially this cerebrum on a stalk or on the brain stem. And when the head hits in
any direction, there’s going to be not only the impact in
certain areas of the brain — usually that frontal lobe
which we talked about — also the temporal
lobes are more common than other places to be injured. And those are going to
essentially hit the side of the skull and cause
bruising or contusions. But at the same time,
those densities and different densities
are going to rotate at different speeds. And you’re actually going to
get a tearing that can occur or a shearing type of
injury that can occur at different areas
throughout the brain, and that’s called
diffuse axonal injury, giving us more widespread
effects. Those tend to occur at what’s
called the gray white matter junction, which is where the
axons have an insulation on them where that insulation changes. But also it can happen at some
of the midline structures, basically where that stalk
or the brain stem is coming into the cerebrum where
you get a twisting motion. And those can tear
through the brain stem and the corpus callosum, which
is our only real connection side to side from the right
side of the brain to the left side of the brain. And that’s essentially
what happens at that moment of impact. There are some secondary effects
that happen after that moment of impact where the
brain then has a lot of excitatory amino acids,
which is basically a lot of chemicals being
released all at once, causing additional damage
and additional cell death. And that causes swelling, which causes additional
cell problems and death. So those are quite a few things
that still are happening there. And then whatever is happening
to that person at that time, are they having trouble
getting oxygen to the brain, anything else. So there’s a lot of
issues that happen with that moment of injury.>>Interviewer: How does the
brain recover from an injury?>>Dr. Wolf: Well, the recovery
is kind of the opposite of that. And so we have all of these — the secondary effects that
I talked about with all of those excitatory amino acids. And all the different
chemicals being released, those start to down-regulate
and disappear out of the brain. And with that goes a
decrease in the swelling. And we will see some initial
recovery just purely on the fact that that swelling
is going down. And that over time
will decrease some of the functional
ramifications of the injury. But then, after that, we’re pretty sure there’s
not a tremendous amount of actual recovery
of dead cells. Once those cells are
damaged, we have to rely on the brain’s healing
mechanisms to essentially compensate
for that.>>Interviewer: So,
Chris, could one area of the brain that’s damaged,
could one area of it compensate for another area
that is damaged?>>Dr. Wolf: Somewhat. They can’t take on
tremendous new roles, but there’s usually quite a
few essentially double wiring, more or less. And so, yes, there
is some of that where the brain shifts
its focus a little bit. But oftentimes we have
to substitute and relearn and teach it, basically
get the wires to reconnect in a different way.>>Interviewer: All right, Chris. Thank you very much
for being with us. We appreciate your insight.>>Dr., Wolf: Well, thank you.>>Interviewer: And thank you
for watching this interview on an overview of TBI, a service of the Brain Injury
Guide and Resources. [ Music ]

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