Alzheimer's
disease
Overview
Alzheimer's disease is a
progressive neurologic disorder that causes the brain to shrink (atrophy) and
brain cells to die. Alzheimer's disease is the most common cause of dementia —
a continuous decline in thinking, behavioral and social skills that affects a
person's ability to function independently.
Approximately 5.8 million
people in the United States age 65 and older live with Alzheimer's disease. Of
those, 80% are 75 years old and older. Out of the approximately fifty million
people worldwide with dementia, between 60% and 70% are estimated to have
Alzheimer's disease.
The early signs of the
disease include forgetting recent events or conversations. As the disease
progresses, a person with Alzheimer's disease will develop severe memory
impairment and lose the ability to conduct everyday tasks.
Medications may temporarily
improve or slow progression of symptoms. These treatments can sometimes help
people with Alzheimer's disease maximize function and maintain independence for
a time. Different programs and services can help support people with
Alzheimer's disease and their caregivers.
There is no treatment that
cures Alzheimer's disease or alters the disease process in the brain. In
advanced stages of the disease, complications from severe loss of brain
function — such as dehydration, malnutrition, or infection — result in death.
Symptoms
Memory loss is the key
symptom of Alzheimer's disease. Early signs include difficulty remembering
recent events or conversations. As the disease progresses, memory impairments worsen,
and other symptoms develop.
At first, a person with
Alzheimer's disease may be aware of having difficulty remembering things and
organizing thoughts. A family member or friend may be more likely to notice how
the symptoms worsen.
Brain changes associated
with Alzheimer's disease led to growing trouble with:
Memory
Everyone has occasional
memory lapses, but the memory loss associated with Alzheimer's disease persists
and worsens, affecting the ability to function at work or at home.
People with Alzheimer's may:
Repeat statements and
questions over and over
Forget conversations, appointments,
or events, and not remember them later
Routinely misplace
possessions, often putting them in illogical locations
Get lost in familiar places
Eventually forget the names
of family members and everyday objects
Have trouble finding the
right words to identify objects, express thoughts or take part in conversations
Thinking and reasoning
Alzheimer's disease causes
difficulty concentrating and thinking, especially about abstract concepts such
as numbers.
Multitasking is especially
difficult, and it may be challenging to manage finances, balance checkbooks and
pay bills on time. Eventually, a person with Alzheimer's may be unable to
recognize and deal with numbers.
Making judgments and
decisions
Alzheimer's causes a decline
in the ability to make reasonable decisions and judgments in everyday
situations. For example, a person may make poor or uncharacteristic choices in
social interactions or wear clothes that are inappropriate for the weather. It
may be more difficult to respond effectively to everyday problems, such as food
burning on the stove or unexpected driving situations.
Planning and performing
familiar tasks
Once-routine activities that
require sequential steps, such as planning and cooking a meal or playing a
favorite game, become a struggle as the disease progresses. Eventually, people
with advanced Alzheimer's often forget how to perform basic tasks such as
dressing and bathing.
Changes in personality and
behavior
Brain changes that occur in
Alzheimer's disease can affect moods and behaviors. Problems may include the
following:
Depression
Apathy
Social withdrawal
Mood swings
Distrust in others
Irritability and
aggressiveness
Changes in sleeping habits
Wandering
Loss of inhibitions
Delusions, such as believing
something has been stolen
Preserved skills
Many important skills are
preserved for longer periods even while symptoms worsen. Preserved skills may
include reading or listening to books, telling stories and reminiscing,
singing, listening to music, dancing, drawing, or doing crafts.
These skills may be
preserved longer because they are controlled by parts of the brain affected
later in the course of the disease.
When to see a doctor
A number of conditions,
including treatable conditions, can result in memory loss or other dementia
symptoms. If you are concerned about your memory or other thinking skills, talk
to your doctor for a thorough assessment and diagnosis.
If you are concerned about
thinking skills you observe in a family member or friend, talk about your concerns,
and ask about going together to a doctor's appointment.
Causes
The exact causes of
Alzheimer's disease are not fully understood. But at a basic level, brain
proteins fail to function normally, which disrupts the work of brain cells
(neurons) and triggers a series of toxic events. Neurons are damaged, lose
connections to each other and eventually die.
Scientists believe that for
most people, Alzheimer's disease is caused by a combination of genetic,
lifestyle and environmental factors that affect the brain over time.
Less than 1% of the time,
Alzheimer's is caused by specific genetic changes that virtually guarantee a
person will develop the disease. These rare occurrences usually result in
disease onset in middle age.
The damage most often starts
in the region of the brain that controls memory, but the process begins years
before the first symptoms. The loss of neurons spreads in a predictable pattern
to other regions of the brains. By the late stage of the disease, the brain has
shrunk significantly.
Researchers trying to understand
the cause of Alzheimer's disease are focused on the role of two proteins:
Plaques. Beta-amyloid is a
fragment of a larger protein. When these fragments cluster together, they have
a toxic effect on neurons and to disrupt cell-to-cell communication. These
clusters form larger deposits called amyloid plaques, which also include other
cellular debris.
Tangles. Tau proteins play a
part in a neuron's internal support and transport system to carry nutrients and
other essential materials. In Alzheimer's disease, tau proteins change shape
and organize themselves into structures called neurofibrillary tangles. The
tangles disrupt the transport system and are toxic to cells.
Risk factors
Age
Increasing age is the
greatest known risk factor for Alzheimer's disease. Alzheimer's is not a part
of normal aging, but as you grow older the likelihood of developing Alzheimer's
disease increases.
One study, for example,
found that annually there were four new diagnoses per 1,000 people ages 65 to
74, 32 new diagnoses per 1,000 people ages 75 to 84, and 76 new diagnoses per
1,000 people aged eighty-five and older.
Family history and genetics
Your risk of developing
Alzheimer's is higher if a first-degree relative — your parent or sibling — has
the disease. Most genetic mechanisms of Alzheimer's among families remain unexplained,
and the genetic factors are complex.
One better understood
genetic factor is a form of the apolipoprotein E gene (APOE). A variation of
the gene, APOE e4, increases the risk of Alzheimer's disease. Twenty-five
percent to 30% of the population carries an APOE e4 allele, but not everyone
with this variation of the gene develops the disease.
Scientists have identified
rare changes (mutations) in three genes that virtually guarantee a person who
inherits one of them will develop Alzheimer's. But these mutations account for
less than 1% of people with Alzheimer's disease.
Down syndrome
Many people with Down
syndrome develop Alzheimer's disease. This is related to having three copies of
chromosome 21 — and subsequently three copies of the gene for the protein that
leads to the creation of beta-amyloid. Signs and symptoms of Alzheimer's tend
to appear 10 to 20 years earlier in people with Down syndrome than they do for
the general population.
Sex
There appears to be slight
difference in risk between men and women, but, overall, there are more women
with the disease because they live longer than men.
Mild cognitive impairment
Mild cognitive impairment
(MCI) is a decline in memory or other thinking skills that is greater than
normal for a person's age, but the decline does not prevent a person from
functioning in social or work environments.
People who have MCI have a
significant risk of developing dementia. When the primary MCI deficit is
memory, the condition is more likely to progress to dementia due to Alzheimer's
disease. A diagnosis of MCI encourages a greater focus on healthy lifestyle
changes, developing strategies to make up for memory loss and scheduling
regular doctor appointments to monitor symptoms.
Head trauma
People who have had a severe
head trauma have a greater risk of Alzheimer's disease. Several large studies
found that in people aged 50 years or older who had a traumatic brain injury
(TBI), the risk of dementia and Alzheimer's disease increased. The risk
increases in people with more severe and multiple TBIs. Some studies indicate
that the risk may be greatest within the first six months to two years after
the TBI.
Air pollution
Studies in animals have
indicated that air pollution particulates can speed degeneration of the nervous
system. And human studies have found that air pollution exposure — particularly
from traffic exhaust and burning wood — is associated with greater dementia
risk.
Excessive alcohol
consumption
Drinking copious amounts of
alcohol has long been known to cause brain changes. Several large studies and
reviews found that alcohol use disorders were linked to an increased risk of
dementia, particularly early-onset dementia.
Poor sleep patterns
Research has shown that poor
sleep patterns, such as difficulty falling asleep or staying asleep, are
associated with an increased risk of Alzheimer's disease.
Lifestyle and heart health
Research has shown that the
same risk factors associated with heart disease may also increase the risk of
Alzheimer's disease. These include:
Lack of exercise
Obesity
Smoking or exposure to
secondhand smoke
High blood pressure
High cholesterol
Poorly controlled type 2
diabetes
These factors can all be
modified. Therefore, changing lifestyle habits can to some degree alter your
risk. For example, regular exercise and a healthy low-fat diet rich in fruits
and vegetables are associated with a decreased risk of developing Alzheimer's
disease.
Lifelong learning and social
engagement
Studies have found an association
between lifelong involvement in mentally and socially stimulating activities
and a reduced risk of Alzheimer's disease. Low education levels — less than a
high school education — appear to be a risk factor for Alzheimer's disease.
Complications
Memory and language loss,
impaired judgment and other cognitive changes caused by Alzheimer's can
complicate treatment for other health conditions. A person with Alzheimer's
disease may not be able to:
Communicate that he or she
is experiencing pain
Explain symptoms of another
illness
Follow a prescribed
treatment plan
Explain medication side
effects
As Alzheimer's disease
progresses to its last stages, brain changes begin to affect physical
functions, such as swallowing, balance, and bowel and bladder control. These
effects can increase vulnerability to additional health problems such as:
Inhaling food or liquid into
the lungs (aspiration)
Flu, pneumonia, and other
infections
Falls
Fractures
Bedsores
Malnutrition or dehydration
Constipation or diarrhea
Dental problems such as
mouth sores or tooth decay
Prevention
Alzheimer's disease is not a
preventable condition. However, a number of lifestyle risk factors for
Alzheimer's can be modified. Evidence suggests that changes in diet, exercise,
and habits — steps to reduce the risk of cardiovascular disease — may also
lower your risk of developing Alzheimer's disease and other disorders that
cause dementia. Heart-healthy lifestyle choices that may reduce the risk of
Alzheimer's include the following:
Exercising regularly
Eating a diet of fresh
produce, healthy oils, and foods low in saturated fat such as a Mediterranean
diet
Following treatment
guidelines to manage high blood pressure, diabetes, and high cholesterol
Asking your doctor for help
to quit smoking if you smoke
Studies have shown that
preserved thinking skills later in life and a reduced risk of Alzheimer's
disease are associated with participating in social events, reading, dancing,
playing board games, creating art, playing an instrument, and other activities
that require mental and social engagement.
Jan Ricks Jennings, MHA,
LFACHE
Senior Consultant
Senior Management
Resources, LLC
724.733.0509 Office
412.913.0636 Cell
January 22, 2022
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