Stages of dementia and Alzheimer's disease

- [Voiceover] So, Alzheimer's
disease, vascular dementia,

Lewy body dementia, and
every other type of dementia

causes damage to your brain cells, right,

which, in turn, causes some
difficulties with various

things your brain controls,
like memory, language,

reasoning, and judgement.

But a lot of the time,
these signs and symptoms

can present themselves
slightly differently.

Since Alzheimer's disease
accounts for the majority

of dementia cases and
the other forms can often

overlap anyways, the
main focus here will be

on the symptoms and progression
of Alzheimer's disease.

Dementia in Alzheimer's
disease typically develop

over the course of years,
but the speed at which

it develops can vary pretty dramatically,

from four years in some patients,

eight in others, and
even as high as 20 years

in some cases.

We're going to go through
some of the general stages

of progressing Alzheimer's disease,

but considering that it's
such a gradual disease,

it's actually really tough
to classify this progression.

And it's important to remember
that there are no clear-cut

or well-defined stages,
and many of these stages

that we'll go through can even overlap.

But, with that said, there
are a few models that are used

for the progression of
Alzheimer's disease,

and we're going to sort
of combine the definitions

from a more broad three-stage model

and also the more specific
seven-stage Reisberg Scale.

So, from the three-stage
model, we have the very early

to mild stages of
Alzheimer's, lasting about two

to seven years.

And then, if we look
at the Reisberg Scale,

stage one is simply no impairment.

So, your memory and cognitive
abilities appear normal,

especially to everyone else.

If there are any
impairments, they might only

be slightly apparent to
the patient themselves.

Stage two, however, is a
very mild cognitive decline.

So, maybe they have
some trouble remembering

recent events or information,
but it could be more subtle

things like forgetting a
word or misplacing things.

And, again, at this stage,
these lapses and changes

in thinking aren't usually
detected by friends,

family, or even medical
personnel, especially considering

half of all people over
65 begin noticing problems

with concentration and word recall

just as a normal consequence of aging.

Stage three is signs of
early confusion and mild

cognitive impairment.

At this point, subtle
difficulties can start to impact

their daily life.

The patient might consciously
or even subconsciously

try to hide these issues.

They might have trouble retrieving words,

remembering what was just said or read,

and planning and organizing,
which can all start

to affect life at home or at work.

It could still be difficult,
though, to diagnose Alzheimer's

at this very early stage.

Now, stage four is considered
mild Alzheimer's disease.

This stage lasts about two years.

And during these two years,
things like financials

and math start to become very challenging.

And the ability to remember recent events

and what was just learned
becomes increasingly difficult.

The patient might have
trouble carrying out tasks,

especially if there
are specific sequences,

like cooking or driving.

But the patients are still
usually able to recognize

their family and friends,
although a diagnosis at this stage

is usually accurate.

Stage five is considered early dementia

to moderate Alzheimer's disease.

In this stage, cognitive
decline starts to become

more drastic, and the
patient requires assistance.

They'll probably have
trouble remembering things

like address or phone number
and can be disoriented

very easily regarding the time or place.

Decision and judgement
skills can also be affected,

like choosing the appropriate clothes

for the day or season.

And so, the patient may
need increased supervision.

This stage can last an
average of about 1.5 years.

Stage six is considered moderately severe

Alzheimer's disease, and in this stage,

there's a significant lack of
awareness of present events,

and this inability to
remember the past and carry on

a conversation, and they'll
likely need help with basic

daily tasks like getting dressed, eating,

and going to the bathroom.

The patient will likely
be unable to recall names

of family members but will likely know

that they're familiar.

This stage lasts about 2.5 years.

In the final stage or
stage seven, speech becomes

severely limited, and
we see a serious decline

in basic abilities.

Even movement abilities
begin to be affected

as the disease has started
to spread to those areas

of the brain, so eating, walking, sitting,

or even standing up all start to fade.

And patients will likely
need extensive assistance

eating and drinking, as
they can lose the ability

to discern when they're thirsty or hungry.

And so they need total
assistance around the clock

for all functions of daily life and care.

And at this stage, due
to these inabilities,

they become much more susceptible

to secondary complications,
diseases and infections,

especially pneumonia and falls.

And this final stage can last from one

to two and a half years.

But, again, it's very important
to stress the flexibility

in this timeline, in these stages.

Not all patients with
Alzheimer's will experience

this exact progression,
and some may deviate

significantly from the expected
duration with each stage

and the disease itself.