- [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.