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Contents
Introduction
Dementia is a brain disorder
that seriously affects a
person's ability to carry
out daily activities. The
most common form of dementia
among older people is
Alzheimer's disease (AD),
which involves the parts of
the brain that control
thought, memory, and
language. Although
scientists are learning more
every day, right now they
still do not know what
causes AD, and there is no
cure.
Scientists think that as
many as 4.5 million
Americans suffer from AD.
The disease usually begins
after age 60, and risk goes
up with age. While younger
people also may get AD, it
is much less common. About 5
percent of men and women
ages 65 to 74 have AD, and
nearly half of those age 85
and older may have the
disease. It is important to
note, however, that AD is
not a normal part of aging.
AD is named after Dr. Alois
Alzheimer, a German doctor.
In 1906, Dr. Alzheimer
noticed changes in the brain
tissue of a woman who had
died of an unusual mental
illness. He found abnormal
clumps (now called amyloid
plaques) and tangled bundles
of fibers (now called
neurofibrillary tangles).
Today, these plaques and
tangles in the brain are
considered signs of AD.
Scientists also have found
other brain changes in
people with AD. Nerve cells
die in areas of the brain
that are vital to memory and
other mental abilities.
There also are lower levels
of some of the chemicals in
the brain that carry
messages back and forth
between nerve cells. AD may
impair thinking and memory
by disrupting these
messages.
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What Causes AD?
Scientists do not yet fully
understand what causes AD.
There probably is not one
single cause, but several
factors that affect each
person differently. Age is
the most important known
risk factor for AD. The
number of people with the
disease doubles every 5
years beyond age 65.
Family history is another
risk factor. Scientists
believe that genetics may
play a role in many AD
cases. For example, familial
AD, a rare form of AD that
usually occurs between the
ages of 30 and 60, is
inherited. The more common
form of AD is known as
late-onset. It occurs later
in life, and no obvious
inheritance pattern is seen.
However, several risk factor
genes may interact with each
other to cause the disease.
The only risk factor gene
identified so far for
late-onset AD, is a gene
that makes one form of a
protein called
apolipoprotein E (apoE).
Everyone has apoE, which
helps carry cholesterol in
the blood. It is likely that
other genes also may
increase the risk of AD or
protect against AD, but they
remain to be discovered. The
National Institute on Aging
(NIA), part of the National
Institutes of Health, is
sponsoring the AD Genetics
Initiative to recruit
families with AD to learn
more about risk factor
genes. To participate in
this study, families should
contact the National Cell
Repository for AD toll-free
at 1-800-526-2839 or send an
e-mail to: alzstudy@iupui.edu.
Scientists still need to
learn a lot more about what
causes AD. In addition to
genetics and apoE, they are
studying education, diet,
and environment to learn
what role they might play in
the development of this
disease. Scientists are
finding increasing evidence
that some of the risk
factors for heart disease
and stroke, such as high
blood pressure, high
cholesterol, and low levels
of the vitamin folate, may
predispose people to AD.
Evidence for physical,
mental, and social
activities as protective
factors against AD is also
increasing.
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What Are the Symptoms of AD?
AD begins slowly. At first,
the only symptom may be mild
forgetfulness. In this
stage, people may have
trouble remembering recent
events, activities, or the
names of familiar people or
things. They may not be able
to solve simple math
problems. Such difficulties
may be a bother, but usually
they are not serious enough
to cause alarm.
However, as the disease goes
on, symptoms are more easily
noticed and become serious
enough to cause people with
AD or their family members
to seek medical help. For
example, people in the
middle stages of AD may
forget how to do simple
tasks, like brushing their
teeth or combing their hair.
They can no longer think
clearly. They begin to have
problems speaking,
under-standing, reading, or
writing. Later on, people
with AD may become anxious
or aggressive, or wander
away from home. Eventually,
patients need total care.
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How is AD Diagnosed?
An early, accurate diagnosis
of AD helps patients and
their families plan for the
future. It gives them time
to discuss care while the
patient can still take part
in making decisions. Early
diagnosis will also offer
the best chance to treat the
symptoms of the disease.
Today, the only definite way
to diagnose AD is to find
out whether there are
plaques and tangles in brain
tissue. To look at brain
tissue, how-ever, doctors
must wait until they do an
autopsy, which is an
examination of the body done
after a person dies.
Therefore, doctors can only
make a diagnosis of
"possible" or "probable" AD
while the person is still
alive.
At specialized centers,
doctors can diagnose AD
correctly up to 90 percent
of the time. Doctors use
several tools to diagnose
"probable" AD, including:
questions about the person's
general health, past medical
problems, and the history of
any difficulties the person
has carrying out daily
activities, tests of memory,
problem solving, attention,
counting, and language,
medical tests-such as tests
of blood, urine, or spinal
fluid, and brain scans.
Some of these test results
help the doctor find other
possible causes of the
person's symptoms. For
example, thyroid problems,
drug reactions, depression,
brain tumors, and blood
vessel disease in the brain
can cause AD-like symptoms.
Some of these other
conditions can be treated
successfully.
Recently, scientists have
focused on a type of memory
change called mild cognitive
impairment (MCI), which is
different from both AD and
normal age-related memory
change. People with MCI have
ongoing memory problems, but
they do not have other
losses like confusion,
attention problems, and
difficulty with language.
Scientists funded by the NIA
are studying information
collected from the Memory
Impairment Study to learn
whether early diagnosis and
treatment of MCI might
prevent or slow further
memory loss, including the
development of AD.
Scientists are finding that
damage to parts of the brain
involved in memory, such as
the hippocampus, can
sometimes be seen on brain
scans before symptoms of the
disease occur. The NIA will
be funding the AD
Neuroimaging Initiative, a
study that will find out
whether brain scans can
diagnose AD early. These
brain scans and other
potential "biomarkers" have
the potential for speeding
the testing of drugs for MCI
and AD.
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How is AD Treated?
AD is a slow disease,
starting with mild memory
problems and ending with
severe brain damage. The
course the disease takes and
how fast changes occur vary
from person to person. On
average, AD patients live
from 8 to 10 years after
they are diagnosed, though
the disease can last for as
many as 20 years.
No treatment can stop AD.
However, for some people in
the early and middle stages
of the disease, the drugs
tacrine (Cognex), donepezil
(Aricept), rivastigmine (Exelon),
or galantamine (Reminyl) may
help prevent some symptoms
from becoming worse for a
limited time. Another drug,
memantine (Namenda), has
been approved for treatment
of moderate to severe AD.
Also, some medicines may
help control behavioral
symptoms of AD such as
sleeplessness, agitation,
wandering, anxiety, and
depression. Treating these
symptoms often makes
patients more comfortable
and makes their care easier
for caregivers.
Developing new treatments
for AD is an active area of
research. Scientists are
testing a number of drugs to
see if they prevent AD, slow
the disease, or help reduce
symptoms.
There is evidence that
inflammation in the brain
may contribute to AD damage.
Some scientists believe that
drugs such as nonsteroidal
anti-inflammatory drugs (NSAIDs)
might help slow the
progression of AD, although
recent studies of two of
these drugs, rofecoxib (Vioxx)
and naproxen (Aleve), have
shown that they did not
delay the progression of AD
in people who already have
the disease. Now, scientists
are studying the NSAIDs
celecoxib (Celebrex) and
naproxen to find out if they
can slow the onset of the
disease.
Research has shown that
vitamin E slows the progress
of some consequences of AD
by about 7 months.
Scientists now are studying
vitamin E to learn whether
it can prevent or delay AD
in patients with MCI.
Recent research suggests
that ginkgo biloba may be of
some help in treating AD
symptoms. There is no
evidence that ginkgo will
cure or prevent AD.
Scientists now are trying to
find out whether ginkgo
biloba can delay or prevent
dementia in older people.
Recent findings from the
Women's Health Initiative (WHI)
highlight the importance of
clinical trials, which are
studies to find out whether
a treatment is both safe and
effective. Earlier studies
had suggested that the
hormone replacement therapy
that millions of women take
after menopause may be
protective against AD.
However, the WHI clinical
trial found an increased
risk of AD in women taking
hormones as compared with
those taking an inactive
pill. The trial used a
commonly pre-scribed pill
combining estrogens and
progesterone. Further
studies on estrogen alone
and other hormone
preparations, such as the
estrogen patch, continue.
People with AD and those
with MCI who want to help
scientists test possible
treatments may be able to
take part in clinical
trials. Healthy people also
can help scientists learn
more about the brain and AD.
The NIA and the Food and
Drug Administration (FDA)
are working together to
maintain the AD Clinical
Trials Database, which lists
AD clinical trials sponsored
by the Federal government
and private companies. To
find out more about these
studies, contact the NIA's
Alzheimer's Disease
Education and Referral (ADEAR)
Center at 1-800-438-4380, or
visit the ADEAR Center Web
site at www.alzheimers.org.
You also can sign up for
e-mail alerts on new
clinical trials that have
been added to the database.
Many of these studies are
being done at NIA-supported
Alzheimer's Disease Centers
located throughout the
United States. These centers
carry out a wide range of
research, including studies
of the causes, diagnosis,
treatment, and management of
AD. To get a list of these
centers, contact the ADEAR
Center.
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Is There Help for
Caregivers?
Most often, spouses or other
family members provide the
day-to-day care for people
with AD. As the disease gets
worse, people often need
more and more care. This can
be hard for caregivers and
can affect their physical
and mental health, family
life, job, and finances.
The Alzheimer's Association
has chapters nationwide that
provide educational programs
and support groups for
caregivers and family
members of people with AD.
For more information,
contact the Alzheimer's
Association listed at the
end of this fact sheet.
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Research
Scientists have come a long
way in their understanding
of AD. Findings from years
of research have begun to
clarify differences between
normal age-related memory
changes, MCI, and AD.
Scientists also have made
great progress in defining
the changes that take place
in the AD brain, which
allows them to pinpoint
possible targets for
treatment. These advances
are the foundation for the
National Institutes of
Health (NIH) Alzheimer's
Disease Prevention
Initiative, which is
designed to:
-
understand why AD occurs
and who is at greatest
risk of developing it;
-
improve the accuracy of
diagnosis and the ability
to identify those at risk;
-
discover, develop, and
test new treatments;
-
discover treatments for
behavioral problems in
patients with AD.
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For More Information
To learn about support
groups, services, research
centers, getting involved in
studies, and publications
about AD, contact the
following:
Alzheimer's Association
225 N. Michigan Avenue,
Suite 1700
Chicago, IL 60611-1676
1-800-272-3900
Website:
www.alz.org
This non-profit association
supports families and
caregivers of patients with
AD. Chapters nationwide
provide referrals to local
resources and services, and
sponsor support groups and
educational programs.
Alzheimer's Disease
Education and Referral (ADEAR)
Center
P.O. Box 8250
Silver Spring, MD 20907-8250
1-800-438-4380
Website:
www.alzheimers.org
This service of the NIA is
funded by the Federal
Government. It offers
information and publications
on diagnosis, treatment,
patient care, caregiver
needs, long-term care,
education and training, and
research related to AD.
Publications can be
previewed and ordered on the
Web site. Staff answer
telephone, e-mail, and
written requests and make
referrals to local and
national resources.
Eldercare Locator
800-677-1116
Website:
www.eldercare.gov
This service of the
Administration on Aging is
funded by the Federal
Government. It offers
information about and
referrals to respite care
and other home and community
services offered by State
and Area Agencies on Aging.
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U.S. DEPARTMENT OF HEALTH
AND HUMAN SERVICES
Public Health Service
National Institutes of
Health
National Institute on
Aging
NIH Publication No.
03-3431
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