Other types of dementia | Mental health | NCLEX-RN | Khan Academy

- [Voiceover] So, Dementia is
this general term we use when

someone starts having trouble
remembering, communicating,

and understanding.

And Alzheimer's Disease is a
specific type of dementia that

accounts for about 60 to
80% of all dementia cases.

But what about the other 20 to 40%?

Well, the second most common type,

accounting for about 20
to 30% of dementia cases,

is called Vascular Dementia.

So, what do all the cells in your body,

regardless of what they
do, need to survive?

Oxygen. They all need oxygen.

Your brain cells are
definitely no different.

Actually, they are probably
the biggest oxygen hogs

in the body.

Every time our heart beats,
we pump about 20 to 25 % of

that blood straight to our brain cells.

So, if there are so many
brain cells, or neurons,

that need so much oxygen,
you can imagine that

the brain is especially
vulnerable and sensitive to

a lack in blood flow.

So, when they don't get that
oxygen. or get less of it,

they can be damaged, or
even start to die off.

So, if, for example, your
cells in your temporal lobe

don't get enough oxygen
and start to die off,

it's going to be more difficult
to remember things and

form new memories because that's
the area of your brain that

controls those things.

And so this is why we
call it Vascular Dementia,

where the Vascular part
refers to the blood supply and

the blood vessels supplying the brain.

If there's any lack in
blood flow to the brain as

a result of a lowered blood supply,

then loss of brain cells can follow and

loss of certain mental functions.

With Vascular Dementia,
changes in thinking skills can

happen suddenly following
some sort of sudden damage,

from a major stroke, maybe,
which is an interruption in

the blood supply to the brain.

Also, though, changes
in thinking skills can

come about gradually
due to minor strokes or

a small vessel supplying
the brain become blocked,

leading to a more progressive damage.

So, because it's related
to your blood supply and

your cardiovascular
system, risk factors are

very similar to the ones that
could also raise your risk for

heart diseases, blood
vessel problems, and stroke.

Some of these are things like
smoking, high blood pressure,

lack of exercise, obesity,
and an unhealthy diet.

Alright. So, that's the second
most common type of dementia.

The third most common type is called

Dementia with Lewy Bodies
and this accounts for about

10 to 25% of all dementia cases.

And this type is caused by
abnormal protein structures

forming inside your neurons,
called Lewy bodies, which

are named after Dr. Friedrich Lewy,

who discovered them in the early 1900s.

Now, these Lewy bodies are
actually accumulated bits of

a protein called Alpha-synuclein.

And you can find these guys
hanging out in your brain cells,

or your neurons.

These Alpha-synuclein proteins are

found widely throughout the brain,

but their exact function
isn't fully understood yet.

One thing we do know is
that when your cells can't

properly process these proteins,
they start to accumulate

and sort of build up forming
these Lewy bodies and,

ultimately, end up damaging the cell.

Symptoms of Lewy Body Dementia include

problems with thinking and memory,

movements and trembling,
hallucinations, and

even physically acting out dreams,

like sleepwalking,
talking or sleep kicking.

Similarly to Alzheimer's,
scientists have yet to

figure out what the direct
and specific cause for

this build-up of Lewy Bodies is and

research remains ongoing.

On thing they do know, though,

is that these Lewy Bodies
can also be found in

patients with Alzheimer's
Disease and Parkinson's Disease,

suggesting that there might
be some similarities in

how the brain has trouble breaking down

these types of proteins.

With that said, patients
with Parkinson's Disease

can develop dementia later on and

if this happens, we call it
Parkinson's Disease Dementia.

And Parkinson's Disease
alone usually affects

your motor control, right?

With this type of Dementia,
the Parkinson's Disease has

progressed to a point where
it's started affecting

mental functions in addition
to your motor functions.

Now, another type of Dementia
is Frontotemporal Dementia,

which used to be called Pick's Disease.

And this type involves damage
to the neurons that are

specifically located in the
frontal and temporal lobes

of the brain.

And when these neurons are damaged,

things specific to those
regions become affected, right?

Like, spacial orientation
in the frontal lobe or

problems with speech from
damage to the temporal lobe.

Now, dementia, in general,
can also be caused, or

brought about, by other factors that

result in some kind of
accumulative damage to your brain.

For example, the toxic effects
of alcohol on brain cells

through alcohol misuse can
damage brain tissue, or

repeated head injuries,
like those sustained by

professional boxers or football players,

and we're talking about both
American football and soccer,

can seriously damage
brain tissue over time.

And it's also not uncommon for there to be

more than one type of dementia present.

For example, you could
have Alzheimer's Disease,

but also have Vascular Dementia as well.