Now, I've got a question for you. So this is
the chance where you get to decide
what you think you should
do in this question. Okay. So, because
of the assessment data,
so you may have to pause the video and
go back and look at your notes. That's
fine. That's what we want you to do. But
because of the assessment data,
you suspect that Mr. Johnson has
had a stroke or a TIA.
Which side of the brain is most
likely to be the site of injury
for Mr. Johnson? Okay. So, now you've got
to think back into what you know about
the brain and how it controls the body. So,
pause the video for just a minute.
Please don't peek. See if you can
recall what you think
which side of the brain is most likely
to be the site of injury for Mr. Johnson?
Okay. The answer is, the left side of the
brain is the most likely site of injury
because he has right-sided weakness
and difficulty with speech. Those
are classic signs
of a left-sided stroke.
Now let's look at the difference between
a right-brain and a left-brain stroke.
See, the patient has a stroke on the right
side. He's paralyzed on the left side.
Now we call that hemiplegia,
right? Hemiplegia or
normal people would just say hemiplegia.
But it means – "hemi" means
half, "plegia" means the paralysis. So,
a stroke on the right side causes
paralysis on the left side.
Injury here, paralysis on this side.
They can also do -- some of them
do a left-sided neglect.
Now, I've seen some patients
that were so severe
when they -- they were male patients
when they would shave,
they only wanted to shave the right
side of their face. It was almost as if
the left side didn't exist. It's
really just a bizarre
thing that a brain does after
a stroke, sometimes.
They have some very
so that can make things like stairs or
distances really difficult for patients.
They might tend to deny or minimize
problems. "I'm fine, I'm okay.
It's not a big deal." So,
that's pretty common with someone
who has a right-sided stroke.
They might have some performance issues.
They have a really short attention span.
They can be very impulsive, so this makes
some safety issues. These are the people,
as they're recovering, are likely to jump
out of bed when they don't have
the ability to be safe. So their
judgment and concept of
time can be way, way off.
These are all very common
manifestations that you'll see
from a stroke on the right side, causes
problem on the left side,
but also causes some unusual things like
that spatial perceptual problem.
Now let's look at a stroke on the left
side. That means the injury is
on this side of the brain. The
paralysis or hemiplegia
is on the right side of the brain. They
have difficulty with speech.
Okay, and they have a hard time with
right and left discrimination. They're
very slow in performing things and tasks
and following commands. They're very
cautious. They're very aware of
their deficits. This side is
most often likely to develop
depression and have anxiety.
And they have a difficult time with
comprehension related to language
and particularly math, which, some days, I
swear I've had a left-sided stroke, because I
always have a hard time with math.
Long list. What's the
best thing to do with a long
list? Well, we put
both of these on one slide. Because
if you look at these, look at
the things that are vastly different,
right? Right-sided stroke is impulsive.
A left-sided stroke is cautious and slow.
So spend some time with this slide.
Compare the things that
could be similar and things that
are very, very different.
Pause the video, spend some
time chunking information,
grouping things together, and deciding how
your brain best works to remember them.
Okay. So, let's talk a little
bit about why. Now,
you see we've got a picture there for
you. It's the right side of the
brain, the left side of the brain.
And we're going to talk about
contralateral control. See,
neurons in the cerebral
cortex control movements
of the contralateral
or opposite side limb. So, injury on the right
side gives me problems on the left,
because the right side controls
my left. Injury on the left side,
it's -- that's the one that controls my
right. The answer is contralateral control.
Now, the pyramidal pathways
crosses at the level
of the medulla. So look right there.
They did a beautiful job
for you. Look, the medulla you've got that
lateral corticospinal tract and those
were the fibers crossover. So,
the gray part of the
drawing is showing you that you've
got the brain and the spinal
cord, but we've got the medulla,
right there, and that's where the
crossover happens. Okay. So,
that's where you end up with
the right side controlling the left, and
the left side controlling the right.
Injury on one side of the brain affects
that motor function because of this
crossover, right there at the medulla.
So that's what was called