Last Updated: April 9,
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 initially 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 Alzheimer's, and there is no
Scientists think that as many as 4.5 million Americans suffer
from Alzheimer's disease. 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% 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
Alzheimer's disease 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, and connections between nerve cells are
disrupted. 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.
What Causes Alzheimer's Disease?
Scientists do not yet fully understand what causes Alzheimer's,
but there are several known risk factors:
- Age: The number of people with the disease
doubles every 5 years beyond age 65.
- Family History:
Scientists believe that genetics may play a role in many AD cases.
For example, early-onset familial AD, a rare form of AD that
usually occurs between the ages of 30 and 60, is inherited.
- ApoE: 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. Only
about 15 percent of people have the form that increases the risk of
In addition to the above, 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 also increase the risk of AD.
Evidence for physical, mental, and social activities as protective
factors against Alzheimer's is also increasing.
What Are the Symptoms of Alzheimer's Disease?
Alzheimer's disease begins slowly. At first, the only symptom
may be mild forgetfulness, which can be confused with age-related
memory change. Most people with mild forgetfulness do not have AD.
In the early stage of AD, 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. Forgetfulness
begins to interfere with daily activities. 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
can fail to recognize familiar people and places. They begin to
have problems speaking, understanding, reading, or writing. Later
on, people with AD may become anxious or aggressive,
or wander away from home. Eventually, patients need total care.
How is Alzheimer's Disease Diagnosed?
An early, accurate diagnosis of Alzheimer's 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, however, doctors usually 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:
- Medical History: General health, past medical
problems and ability to carry out daily activities all factor into
Function Evaluation: Tests of memory,
problem solving, attention, and language abilities are
Tests: Doctors will likely run brain
scans, and may collect blood, urine and spinal fluid samples.
Sometimes 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.
How is Alzheimer's Disease Treated?
Alzheimer's disease 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 some people may live
with Alzheimer's 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
(Razadyne, previously known as Reminyl) may help prevent some
symptoms from becoming worse for a limited time. Another drug,
memantine (Namenda), has been approved to treat moderate to severe
AD, although it also is limited in its effects. 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.
Scientists are exploring several new potential Alzheimer's
treatments in hopes of slowing down the disease's progression and
lessening it's effects, including:
- NSAIDS: While early
research hasn't shown that anti-inflammatories have any affect on
preventing Alzheimer's or slowing its progression, because
Alzheimer's is an inflammatory diseases, scientiests are continuing
to test therapeutic regimes involving these drugs.
- Natural Memory
Enhancers: Vitamin E, Ginko biloba and other
naturally occuring memory enhancers hold some promise for those
- Estrogen: This
hormone is known to help protect the brain, and some think it could
help prevent memory loss.
Is There Help for Caregivers?
Most often, spouses and other family members provide the
day-to-day care for people with Alzheimer's disease. 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. Contact information for the Alzheimer's
Association is listed below.