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ALZHEIMER'S DISEASE
Introduction
Alzheimer’s disease is a brain disorder named for German physician
Alois Alzheimer, who first described it in 1906. Scientists have learned a great deal about Alzheimer’s disease in the century since
Dr. Alzheimer first drew attention to it. Today we know that Alzheimer’s:
Is a progressive and fatal brain disease. As many as 5.3
million Americans are living with Alzheimer’s disease. Alzheimer's destroys brain cells, causing memory
loss and problems with thinking and behavior severe enough
to affect work, lifelong hobbies or social life. Alzheimer’s gets worse over time, and it is fatal. Today it is the seventh-
leading cause of death in the United States. Learn more: Warning Signs and Stages of Alzheimer’s Disease.
Is the most common form of dementia, a general term
for memory loss and other intellectual abilities serious enough to interfere with daily life. Alzheimer’s disease accounts for 50
to 80 percent of dementia cases. Other types of dementia include vascular dementia, mixed dementia, dementia with
Lewy bodies and frontotemporal dementia. Learn more: Related Dementias.
Has no current cure. But treatments for symptoms,
combined with the right services and support, can make life better for the millions of Americans living with
Alzheimer’s. There is an accelerating worldwide effort under
way to find better ways to treat the disease, delay its onset, or prevent it from developing. Learn more about recent
progress in Alzheimer research funded by the Alzheimer’s Association in the Research section.
Alzheimer's and the brain
Just like the rest of our bodies, our brains change as we age. Most of us notice some slowed thinking and occasional problems with
remembering certain things. However, serious memory loss, confusion and other major changes in the way our minds work are
not a normal part of aging. They may be a sign that brain cells are failing.
The brain has 100 billion nerve cells (neurons). Each nerve cell
communicates with many others to form networks. Nerve cell
networks have special jobs. Some are involved in thinking, learning
and remembering. Others help us see, hear and smell. Still others tell our muscles when to move. In Alzheimer’s disease, as in other
types of dementia, increasing numbers of brain cells deteriorate and die.
Take the Brain Tour to learn more about how the brain works and
how Alzheimer's disease affects it.
The role of plaques and tangles
Two abnormal structures called plaques and tangles are prime
suspects in damaging and killing nerve cells. Plaques and tangles were among the abnormalities that Dr. Alois Alzheimer saw in the
brain of Auguste D., although he called them different names.
Plaques build up between nerve cells. They contain deposits of a protein fragment called beta-amyloid (BAY-tuh AM-uh-
loyd). Tangles are twisted fibers of another protein called tau
(rhymes with ―wow‖).
Tangles form inside dying cells. Though most people develop some plaques and tangles as they age, those with Alzheimer’s
tend to develop far more. The plaques and tangles tend to form in a predictable pattern, beginning in areas important in
learning and memory and then spreading to other regions.
Scientists are not absolutely sure what role plaques and tangles play in Alzheimer’s disease. Most experts believe they somehow
block communication among nerve cells and disrupt activities that cells need to survive.
Early-stage and younger-onset Alzheimer's disease
Early-stage is the early part of Alzheimer’s disease when problems with memory, thinking and concentration may begin to appear in a
doctor’s interview or medical tests. Individuals in the early-stage typically need minimal assistance with simple daily routines. At the
time of a diagnosis, an individual is not necessarily in the early
stage of the disease; he or she may have progressed beyond the early stage.
The term younger-onset refers to Alzheimer's that occurs in a
person under age 65. Younger-onset individuals may be employed or have children still living at home. Issues facing families include
ensuring financial security, obtaining benefits and helping children cope with the disease. People who have younger-onset dementia
may be in any stage of dementia – early, middle or late. Experts
estimate that some 500,000 people in their 30s, 40s and 50s have
Alzheimer's disease or a related dementia.
About Dr. Alzheimer
At a scientific meeting in November 1906, German physician Alois Alzheimer presented the case of ―Frau Auguste D.,‖ a 51-year-old
woman brought to see him in 1901 by her family. Auguste had
developed problems with memory, unfounded suspicions that her husband was unfaithful, and difficulty speaking and understanding
what was said to her. Her symptoms rapidly grew worse, and within a few years she was bedridden. She died in Spring 1906.
Dr. Alzheimer had never before seen anyone like Auguste D., and
he gained the family’s permission to perform an autopsy. In Auguste’s brain, he saw dramatic shrinkage, especially of the
cortex, the outer layer involved in memory, thinking, judgment and speech. Under the microscope, he also saw widespread fatty
deposits in small blood vessels, dead and dying brain cells, and abnormal deposits in and around cells.
The condition entered the medical literature in 1907, when
Alzheimer published his observations about Auguste D. In 1910,
Emil Kraepelin, a psychiatrist noted for his work in naming and classifying brain disorders, proposed that the disease be named
after Alzheimer.
Auguste D.
10 Signs of Alzheimer's:
Memory loss that disrupts daily life is not a typical part of aging. It
may be a symptom of Alzheimer's, a fatal brain disease that causes a slow decline in memory, thinking and reasoning skills. Every
individual may experience one or more of these signs in different degrees. If you notice any of them, please see a doctor. Learn how
Alzheimer's affects the brain and take the Brain Tour.
10 warning signs of Alzheimer's:
Memory loss that disrupts daily life
One of the most common signs of Alzheimer's is memory loss, especially
forgetting recently learned information. Others include forgetting important dates
or events; asking for the same information over and over; relying on
memory aides (e.g., reminder notes or electronic devices) or family members for things they used to
handle on their own. What's a typical age-related change? Sometimes
forgetting names or appointments, but remembering
them later.
Challenges in planning or solving problems
Some people may experience changes in
their ability to develop and follow a plan or work with numbers. They may have
trouble following a familiar recipe or keeping track of monthly bills. They may
have difficulty concentrating and take much longer to do things than they did before.
What's a typical age-related change? Making
occasional errors when balancing a checkbook.
Difficulty completing familiar tasks at
home, at work or at leisure
People with Alzheimer's often find it hard
to complete daily tasks. Sometimes, people may have trouble driving to a
familiar location, managing a budget at work or remembering the rules of a
favorite game. What's a typical age-related change? Occasionally
needing help to use the settings on a microwave or to record a television show.
Confusion with time or place
People with Alzheimer's can lose track of
dates, seasons and the passage of time. They may have trouble understanding
something if it is not happening immediately. Sometimes they may forget
where they are or how they got there.
What's a typical age-related change? Getting confused
about the day of the week but figuring it out later.
Trouble understanding visual images and
spatial relationships
For some people, having vision problems is a sign of Alzheimer's. They may have difficulty reading, judging distance and
determining color or contrast. In terms of perception, they may pass a mirror and
think someone else is in the room. They may not
realize they are the person in the mirror. What's a typical age-related change? Vision changes
related to cataracts.
New problems with words in speaking or
writing
People with Alzheimer's may have trouble following or joining a conversation. They
may stop in the middle of a conversation and have no idea how to continue or they
may repeat themselves. They may struggle with vocabulary, have problems finding the
right word or call things by the wrong name (e.g.,
calling a "watch" a "hand-clock"). What's a typical age-related change? Sometimes
having trouble finding the right word.
Misplacing things and losing the ability to
retrace steps
A person with Alzheimer's disease may put things in unusual places. They may
lose things and be unable to go back over their steps to find them again.
Sometimes, they may accuse others of
stealing. This may occur more frequently over time. What's a typical age-related change? Misplacing things
from time to time, such as a pair of glasses or the remote control.
Decreased or poor judgment
People with Alzheimer's may experience changes in judgment or decision-making.
For example, they may use poor judgment when dealing with money,
giving large amounts to telemarketers.
They may pay less attention to grooming or keeping themselves clean.
What's a typical age-related change? Making a bad decision once in a while.
Withdrawal from work or social activities
A person with Alzheimer's may start to
remove themselves from hobbies, social activities, work projects or sports. They
may have trouble keeping up with a favorite sports team or remembering how
to complete a favorite hobby. They may also avoid
being social because of the changes they have experienced.
What's a typical age-related change? Sometimes feeling weary of work, family and social obligations.
Changes in mood and personality
The mood and personalities of people
with Alzheimer's can change. They can become confused, suspicious, depressed,
fearful or anxious. They may be easily upset at home, at work, with friends or in
places where they are out of their comfort zone.
What's a typical age-related change? Developing very
specific ways of doing things and becoming irritable
when a routine is disrupted.
The difference between Alzheimer's and typical age-related changes
Signs of Alzheimer's Typical age-related changes
Poor judgment and decision making Making a bad decision once in a
while
Inability to manage a budget Missing a monthly payment
Losing track of the date or the season Forgetting which day it is and
remembering later
Difficulty having a conversation Sometimes forgetting which word
to use
Misplacing things and being unable to retrace steps to find them
Losing things from time to time
Why Get Checked?
If you notice any of the 10 Warning Signs of Alzheimer's in yourself
or someone you know, don't ignore them. Schedule an appointment
with your doctor.
With early detection, you can:
Get the maximum benefit from available treatments – You can
explore treatments that may provide some relief of symptoms and help you maintain a level of independence longer. You may also
increase your chances of participating in clinical drug trials that help
advance research. Have more time to plan for the future – A diagnosis of
Alzheimer's allows you to take part in decisions about care, transportation, living options, financial and legal matters. You can
also participate in building the right care team and social support network. Help for you and your loved ones – Care and support services
are available, making it easier for you and your family to live the best life possible with Alzheimer’s or dementia.
When you see your doctor
Your doctor will evaluate your overall health and identify any conditions that could affect how well your mind is working. Your
doctor may refer you to a specialist such as a:
Neurologist – specializes in diseases of the brain and nervous system
Psychiatrist – specializes in disorders that affect mood or the way the mind works
Psychologist – has special training in testing memory and
other mental functions Geriatrician – specializes in the care of older adults and
Alzheimer's disease
Current Alzheimer Treatments
FDA-approved drugs
The U.S. Food and Drug Administration (FDA) has approved five
medications to treat the symptoms of Alzheimer's disease.
How Alzheimer drugs work
To understand how Alzheimer's medications work, you first need to understand the communication network in the brain. The
picture below depicts nerve cells, or neurons, in the brain. Neurons are the chief cells destroyed by Alzheimer's disease.
Roll your mouse over the red text to highlight the image.
In the brain, neurons connect and communicate at synapses, where tiny bursts of chemicals called neurotransmitters carry
information from one cell to another. Alzheimer's disrupts this process, and eventually destroys synapses and kills neurons,
damaging the brain's communication network.
Current FDA-approved Alzheimer drugs support this communication process through
On average, the five approved Alzheimer drugs are effective for
about six to 12 months for about half of the individuals who take them.
Future treatment breakthroughs
Researchers are looking for new ways to treat Alzheimer's.
Current drugs help mask the symptoms of Alzheimer's, but do not treat the underlying disease. A breakthrough Alzheimer drug
would treat the underlying disease and stop or delay the cell damage that eventually leads to the worsening of symptoms.
Many experts believe such a breakthrough is possible within the
next few years. There are several promising drugs in
development and testing, but we need more volunteers to complete clinical trials of those drugs and increased federal
funding of research to ensure that fresh ideas continue to fill the pipeline
Treatment Horizon:
Right now, there are more potential new Alzheimer drug treatments in development and testing than ever before. New discoveries are fueling steady progress toward possible treatments to stop, slow and even prevent Alzheimer's. Because new drugs take years to produce from concept to market, it is critical that Alzheimer research continues to accelerate. To this end, the Alzheimer's Association funds researchers looking at new treatment strategies
and advocates for more federal funding of Alzheimer research.
The hope for future drugs
Currently, there are five FDA-approved Alzheimer drugs that
treat the symptoms of Alzheimer's — temporarily helping memory and thinking problems in about half of the people who
take them. But these medications do not treat the underlying causes of Alzheimer's.
In contrast, many of the new drugs in development aim to
modify the disease process itself, by impacting one or more of the many wide-ranging brain changes that Alzheimer's causes.
These changes offer potential "targets" for new drugs to stop or slow the progress of the disease. Many researchers believe
successful treatment will eventually involve a "cocktail" of medications aimed at several targets, similar to current state-of-
the-art treatments for many cancers and AIDS.
Targets for future drugs
Over the last 30 years, researchers have made remarkable progress in understanding healthy brain function and what goes
wrong in Alzheimer's disease. The following are examples of promising targets for next-generation drug therapies under
investigation in current research studies:
Beta-amyloid is the chief component of plaques, one hallmark Alzheimer brain
abnormality. Scientists now have a detailed
understanding of how this protein fragment is clipped from its parent compound amyloid
precursor protein (APP) by two enzymes —
beta-secretase and gamma-secretase. Researchers are
developing medications aimed at virtually every point in amyloid processing. This includes blocking activity of both
enzymes; preventing the beta-amyloid fragments from clumping into plaques; and even using antibodies against
beta-amyloid to clear it from the brain. Several clinical trials of investigational drugs targeting beta-amyloid are included
below in the key clinical trial summaries.
Tau protein is the chief component of tangles, the other
hallmark brain abnormality. Researchers are investigating strategies to keep tau molecules from collapsing and twisting
into tangles, a process that destroys a vital cell transport system.
Inflammation is another key Alzheimer brain abnormality. Scientists have learned a great deal about molecules involved
in the body's overall inflammatory response and are working to better understand specific aspects of inflammation most
active in the brain. These insights may point to novel anti-inflammatory treatments for Alzheimer's disease.
Insulin resistance and the way brain cells process insulin
may be linked to Alzheimer's disease. Researchers are exploring the role of insulin in the brain and closely related
questions of how brain cells use sugar and produce energy. These investigations may reveal strategies to support cell
function and stave off Alzheimer-related changes.
Gauging treatment impact with brain imaging and
biomarkers In addition to investigating experimental drugs, many clinical
trials in progress include various brain imaging studies and testing of blood or spinal fluid. Researchers hope these
techniques will one day provide methods to diagnose
Alzheimer's disease in its earliest, most treatable stages — possibly even before symptoms appear. They may also
eventually offer better methods to monitor response to treatment.