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Health and medicine
Course: Health and medicine > Unit 9
Lesson 10: Dementia, delirium, and Alzheimer's- Dementia and Delirium, including Alzheimer’s
- What are dementia and Alzheimer's
- Alzheimer's disease: Plaques and tangles
- Other types of dementia
- Risk factors for dementia
- Stages of dementia and Alzheimer's disease
- Diagnosis of dementia and Alzheimer's disease
- Treatment of dementia and Alzheimer's disease
- What is delirium?
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Risk factors for dementia
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Want to join the conversation?
- Is there any way that we can determine if a young person will have Alzheimer's when they get older? Can the mutated genes be seen long before the person develops Alzheimer's?(1 vote)
- Would a type of cyst located in the frontal lobe create symptoms of dementia?(1 vote)
Video transcript
- [Voiceover] When something increases the chance that you'll
develop a certain disease we call it a risk factor, right? Because essentially it increases your risk or puts you at a higher risk for developing that disease. By far, the most common risk factor for Alzheimer's disease,
vascular dementia, and other types of dementia is age. Dementia is very rare
in people under the age of 65 years old but becomes
very common after age 80. Unfortunately for us, the
fact that we age over time is a risk factor that's completely
out of our control,right? Even more unfortunately,
the reason as to why this risk of developing dementia increases as we get
older is mostly unknown. And another risk factor that tends to be mostly out of our
control is family history. So here's you. Here are your parents. Here are your brother and your
sister and here's your child. If any of your family here
has developed dementia, let's say Alzheimer's
disease because that's the most common, then you're gonna be at a higher risk for developing
the disease yourself. So say someone else in your family also has developed Alzheimer's, then the risk of you
developing Alzheimer's grows even more and this can be the result of environmental factors
like how or in what setting you were raised since it's probably going to be a similar setting for
your immediate family, right? And with Alzheimer's in particular, scientists are well
aware that specific genes are involved even further
Alzheimer's disease has both what we call risk genes and deterministic genes. Now risk genes are defined
just like a risk factor. If you have this specific risk gene, then you're going to be more likely to develop a certain
disease but you're not necessarily going to
develop it, you're just gonna be at higher risk. So the risk gene that
scientists have found that have the strongest association with developing Alzheimer's disease is called Apolipoprotein E-E4 and a lot of times you see
it shortened to APOE-E4. This APOE gene helps us make molecules called lipoproteins which help carry fats and cholesterols through the bloodstream. Maintaining normal levels of cholesterol is very important for helping to prevent a variety of disorders. Now there are three
slightly different versions to this gene also called alleles. You have E2, E3 and E4
and it's the E4 type that increases your risk of Alzheimer's. So if you were to inherit
one copy of this allele you'll be at a greater risk
for developing Alzheimer's and if you inherit two copies, you'll be at even greater risk. It's been suggested that this gene is a factor in about 20-25%
of all Alzheimer's cases. So that's the major risk gene, right? Deterministic genes, on the other hand, directly cause a particular disease. In other words, it determines that the disease will be present and essentially guarantees that anyone that inherits it will
develop the disorder. As applied to Alzheimer's disease, this is called familial Alzheimer's or sometimes early onset Alzheimer's as it can often happen before age 65. Now scientists have discovered that this can be caused by a mutation in
at least one of three genes. You can have a mutation in
amyloid precursor protein or APP, Presenilin-1 or PS-1, or Presenilin-2 or PS-2. When any of these genes
are mutated or altered large amounts of amyloid
plaques tend to build up and these are a major component of Alzheimer's disease, right? Fortunately though, familial
or early onset Alzheimer's resulting from a deterministic
gene is very rare. And there is always
some evidence to suggest that those with Down Syndrome have an increased risk for developing Alzheimer's disease because Down Syndrome occurs when someone has an extra copy of chromosome 21 in every cell which means that many of the genes in their cells have three
copies instead of the usual two and that includes the amyloid
precursor protein gene. Although that's still fully understood, it's thought that this
extra gene might account for an increased production
of amyloid plaques and therefore, increase the
risk for Alzheimer's disease. Now some of the risk factors for dementia and Alzheimer's, however,
are, in fact, in your control. Many experts are starting to reveal trends includes that, start to
hint at, other lifestyle and wellness choices that can have a significant influence on your
risk of developing dementia. And one big, big risk is head trauma and there is a very
strong link that exists between head injury and dementia later on in life,
especially when the trauma is repeated like in high-impact
sports like football or soccer or when loss of
consciousness is involved. With that said, protect your
brain! It's really important! And another risk factor
is actually heart trauma. Scientists and health
professionals are continuing to see links between brain
health and heart health. Many of the risk factors
that lead to heart disease also apply to dementia but why is that? Well, most types of heart disease, your heart gets less efficient
at pumping blood, right? Well, if less blood's getting to brain, it's gonna have an increased
risk of damaging your brain cells and developing
some sort of dementia. So things like poor diet
and obseity, diabetes, smoking and heavy alcohol use will increase your risk of both
heart diseases and dementia. And if there is some
sort of heart conditions that already exist like atherosclerosis or high blood pressure, your risk for dementia increases as well. That being said, protect your heart! It's also important.