Alzheimer’s disease is the most common cause of dementia in the world.
Nearly 50 million people worldwide have it, and every 66 seconds
someone in the United States is diagnosed with it.
It’s been called the epidemic of our century, but even after decades of research, finding
a way to prevent this disease has been a puzzle that
has eluded the medical community.
Now, we may be closer than ever to solving it.
- I personally have a lot of hope that we will see the first survivors of Alzheimer's
disease in our lifetime.
I’m Nilüfer Ertekin-Taner.
I'm a neurologist and I'm a neuroscientist focused on Alzheimer's
disease and related dementias.
Alzheimer's disease is a progressive condition, typically starting in the part of the brain
associated with memory.
It then spreads, causing trouble with memory, cognitive abilities
and eventually, loss of bodily functions.
It's a relentlessly progressive condition that leads to
death by or with the disease.
Age is the most common risk factor for Alzheimer's.
In fact, about a third of individuals ages 85
or above have it.
And while the exact onset of this disease is not known, what is known is that it
is characterized by a buildup of toxic proteins in the brain.
- There are two main hallmarks of Alzheimer's disease in the brain.
One of them is amyloid beta, which builds up in plaques outside of
neurons.
And the other one is tau, which is a fibrillar protein, which builds up inside of neurons.
Both of these proteins are toxic, and ultimately they
lead to dysfunction and death of neurons.
As these proteins accumulate and neurons start to die, the brain’s immune system
kicks into gear.
- The immune cells of the brain, called microglia, try to get rid of these toxic protein substances.
And they also try to get rid of the dead neurons.
Ultimately, this immune response leads to chronic inflammation of the brain.
Over a longer period of time, as the disease progresses
and neural cell death continues, the affected brain
regions begin to shrink.
And that’s about when symptoms start to show.
- Although it starts typically in areas that affect our memory, ultimately it starts affecting
areas that control our movements, that control our
swallowing and our breathing.
And in the terminal stages of this condition, our patients with
Alzheimer's disease lose their ability to move, and
they become bedbound.
And at the end our patients unfortunately succumb to pneumonia,
malnutrition, generalized sepsis of the body.
And this is all because of Alzheimer's disease and
what it does in the brain.
And while this all sounds dire, decades of studies on patients show that there may be
a window of opportunity to prevent the condition advancing
before you would see any symptoms.
- We know that 10 or 20 years before the symptoms of Alzheimer's disease can be observed, there
are changes in the brain.
We know this from biomarker studies looking at levels of abnormal
proteins in the spinal fluid, in the brain, or in blood.
So biomarkers are quantifiable measures that can help us detect disease
or an aspect of the disease.
So for example, we can think blood glucose levels as being a biomarker for diabetes.
We can think about blood pressure measurements as being a biomarker
for high blood pressure.
In the same vein, we have developed, and continue to develop biomarkers for
Alzheimer's disease.
And while these biomarkers are important to follow the disease’s progression the research
is still ongoing.
Right now, knowing a patient's risk factors can help them make choices to slow the
onset of Alzheimer’s.
- Those risk factors that are bad for your heart are generally bad for your brain.
So diabetes, hypertension, smoking and obesity are risk
factors for Alzheimer's disease.
On the flip side, What we recommend to our patients, and even
the general public is that they stay engaged, both
cognitively, physically and socially.
That can be anything from exercise to maintaining a strong social network.
The takeaway seems to be: stay active.
- We are also at an amazing time in research and clinical studies.
We are able to combine clinical information with very complex genetic and
other molecular information.
This helps us try and identify the very complex molecular perturbations
that can lead to this condition.