Alzheimer Disease
ALZHEIMER’S DISEASE
From the Alzheimer’s Disease Education and Referral Center at the National Institute on Aging
What is Alzheimer's disease (AD)?
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 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 AD, and there is no cure.
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, 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.
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How many Americans have AD?
Scientists think that up to 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.
How long can a person live with AD?
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.
What is Dementia?
The term "dementia" describes a group of symptoms that are caused by changes in brain function. Dementia symptoms may include asking the same questions repeatedly; becoming lost in familiar places; being unable to follow directions; getting disoriented about time, people, and places; and neglecting personal safety, hygiene, and nutrition. People with dementia lose their abilities at different rates.
Dementia is caused by many conditions. Some conditions that cause dementia can be reversed, and others cannot. The two most common forms of dementia in older people are Alzheimer's disease and multi-infarct dementia (sometimes called vascular dementia). These types of dementia are irreversible, which means they cannot be cured.
Reversible conditions with symptoms of dementia can be caused by a high fever, dehydration, vitamin deficiency and poor nutrition, bad reactions to medicines, problems with the thyroid gland, or a minor head injury. Medical conditions like these can be serious and should be treated by a doctor as soon as possible.
Sometimes older people have emotional problems that can be mistaken for dementia. Feeling sad, lonely, worried, or bored may be more common for older people facing retirement or coping with the death of a spouse, relative, or friend. Adapting to these changes leaves some people feeling confused or forgetful. Emotional problems can be eased by supportive friends and family, or by professional help from a doctor or counselor.
What is Multi-Infarct Dementia (MID)?
In multi-infarct dementia, a series of small strokes or changes in the brain's blood supply may result in the death of brain tissue. The location in the brain where the small strokes occur determines the seriousness of the problem and the symptoms that arise. Symptoms that begin suddenly may be a sign of this kind of dementia. People with multi-infarct dementia are likely to show signs of improvement or remain stable for long periods of time, then quickly develop new symptoms if more strokes occur. In many people with multi-infarct dementia, high blood pressure is to blame. One of the most important reasons for controlling high blood pressure is to prevent strokes.
More information on other types of dementia:
What is Mild Cognitive Impairment (MCI)?
During the past several years, scientists have focused on a type of memory change called mild cognitive impairment (MCI). MCI is different from both AD and normal age-related memory change. People with MCI have ongoing memory problems but do not have other losses like confusion, attention problems, and difficulty with language.
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, early-onset 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 in most families. However, several risk factor genes may interact with each other and with non-genetic factors 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. Only about 15 percent of people have the form that increases the risk of AD. It is likely that other genes also may increase the risk of AD or protect against AD, but they remain to be discovered.
More information:
The NIA-sponsored AD Genetics Study(PDF, 196K) seeks to learn more about risk factor genes for late onset AD.
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 also increase the risk of AD. Evidence for physical, mental, and social activities as protective factors against AD is also increasing.
More information on risk and protective factors:
Genes, Lifestyles and Crossword Puzzles: Can Alzheimer's Disease be Prevented?
What are the Symptoms of AD?
AD 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.
See Also: The Seven Warning Signs of AD
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.
See Also: Understanding the Stages and Symptoms of AD
Other Causes of Dementia Symptoms
Many different medical conditions may cause symptoms that seem like Alzheimer's disease, but are not. Some of these medical conditions may be treatable. Reversible conditions can be caused by a high fever, dehydration, vitamin deficiency and poor nutrition, bad reactions to medicines, problems with the thyroid gland, or a minor head injury. Medical conditions like these can be serious and should be treated by a doctor as soon as possible.
How is AD Diagnosed?
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 must usually 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 ability to carry out daily activities;
tests to measure memory, problem solving, attention, counting, and language;
medical tests - such as tests of blood, urine, or spinal fluid; and
brain scans.
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.
What is the outlook for someone diagnosed with AD?
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.
Why is early diagnosis important?
An early, accurate diagnosis of AD helps patients and their families plan for the future. It gives them time to discuss care options while the patient can still take part in making decisions. Early diagnosis also offers the best chance to treat the symptoms of the disease.
What drugs are currently available to treat AD?
No treatment has been proven to stop AD. However, for some people in the early and middle stages of the disease, the drugs donepezil (Aricept®), rivastigmine (Exelon®), or galantamine (Razadyne®, formerly known as Reminyl®) may help prevent some symptoms from becoming worse for a limited time in some patients. Another drug, tacrine (Cognex®) was approved by the Food and Drug Administration (FDA), but it is no longer actively marketed by the manufacturer. In addition, the drug, memantine (Namenda®), has been approved to treat moderate to severe AD, although it also is limited in its effects. And the FDA recently approved the use of donepezil to treat 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.
See Also: AD Medications Fact Sheet
What potential new treatments are being researched?
The National Institute on Aging (NIA), part of the National Institutes of Health (NIH), is the lead Federal agency for AD research. NIA-supported scientists are testing a number of drugs to see if they prevent AD, slow the disease, or help reduce symptoms. Some ideas that seem promising turn out to have little or no benefit when they are carefully studied in a clinical trial. Researchers undertake clinical trials to learn whether treatments that appear promising in observational and animal studies actually are safe and effective in people.
Mild Cognitive Impairment. During the past several years, 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 such as confusion, attention problems, and difficulty with language. The NIA-funded Memory Impairment Study compared donepezil (Aricept), vitamin E, or placebo in participants with MCI to see whether the drugs might delay or prevent progression to AD. The study found that the group with MCI taking the drug donepezil were at reduced risk of progressing to AD for the first 18 months of a 3-year study when compared with their counterparts on placebo. The reduced risk of progressing from MCI to a diagnosis of AD among participants on donepezil disappeared after 18 months, and by the end of the study, the probability of progressing to AD was the same in the two groups. Vitamin E had no effect at any time point in the study when compared with placebo.
Neuroimaging. 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. An NIA public-private partnership—the AD Neuroimaging Initiative(ADNI)—is a large study that will determine whether magnetic resonance imaging (MRI) and positron emission tomography (PET) scans, or other imaging or biological markers, can see early AD changes or measure disease progression. The project is designed to help speed clinical trials and find new ways to determine the effectiveness of treatments.
AD Genetics. The NIA is sponsoring the AD Genetics Study to learn more about risk factor genes for late onset AD. To participate in this study, families with two or more living siblings diagnosed with AD should contact the National Cell Repository for AD (NCRAD) toll-free at 1-800-526-2839. Information may also be requested through the study’s website: http://ncrad.iu.edu.
Inflammation. There is evidence that inflammation in the brain may contribute to AD damage. Some studies have suggested that drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs) might help slow the progression of AD, but clinical trials thus far have not demonstrated a benefit from these drugs. A clinical trial studying two of these drugs, rofecoxib (Vioxx) and naproxen (Aleve) showed that they did not delay the progression of AD in people who already have the disease. Another trial, testing whether the NSAIDs celecoxib (Celebrex) and naproxen could prevent AD in healthy older people at risk of the disease, was suspended. However, investigators are continuing to follow the participants and are examining data regarding possible cardiovascular risk. Researchers are continuing to look for ways to test how other anti-inflammatory drugs might affect the development or progression of AD.
Antioxidants. Several years ago, a clinical trial showed that vitamin E slowed the progress of some consequences of AD by about 7 months. Additional studies are investigating whether antioxidants—vitamins E and C—can slow AD. Another clinical trial is examining whether vitamin E and/or selenium supplements can prevent AD or cognitive decline, and additional studies on other antioxidants are ongoing or being planned.
Ginkgo biloba. Early studies suggested that extracts from the leaves of the ginkgo biloba tree may be of some help in treating AD symptoms. There is no evidence yet that ginkgo biloba will cure or prevent AD, but scientists now are trying to find out in a clinical trial whether ginkgo biloba can delay cognitive decline or prevent dementia in older people.
Estrogen. Some studies have suggested that estrogen used by women to treat the symptoms of menopause also protects the brain. Experts also wondered whether using estrogen could reduce the risk of AD or slow the disease. Clinical trials to test estrogen, however, have not shown that estrogen can slow the progression of already diagnosed AD. And one study found that women over the age of 65 who used estrogen with a progestin were at greater risk of dementia, including AD, and that older women using only estrogen could also increase their chance of developing dementia.
Scientists believe that more research is needed to find out if estrogen may play some role in AD. They would like to know whether starting estrogen therapy around the time of menopause, rather than at age 65 or older, will protect memory or prevent AD.
For more information on recent estrogen study findings:
Menopause Companion, 2003 (PDF, 315K)
Understanding the Women's Health Initiative Study of Using Estrogen Alone, June 2004 (PDF, 30K)
What are Clinical Trials?
People with AD, those with MCI, or those with a family history of AD, 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 maintains the AD Clinical Trials Database, which lists AD clinical trials sponsored by the Federal government and private companies. You also can sign up for e-mail alerts on new clinical trials as they are added to the database. Additional clinical trials information is available at www.clinicaltrials.gov.
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.
The NIA also supports the Alzheimer's Disease Cooperative Study (ADCS), a consortium of researchers at 109 sites in the U.S. and Canada conducting large-scale clinical trials of new approaches to treating and preventing AD. The ADCS is based at the University of California, San Diego.
See Also: AD Clinical Trials: Questions & Answers
Caregiving Resources
Who can you call if you need information on finding local resources to help you take care of your father? Are there organizations that will help pay for your mother’s medication? Where can you find support groups for family caregivers?
This resource list includes some useful national organizations available to help answer these questions. It’s organized by category. We’ve included only organizations that serve a national constituency. Phone numbers and web addresses are provided for easy contact. This list does not include every possible resource but it is a place to start in your search for information.
General Resources
The following groups have a wealth of useful information on all aspects of aging – from research to services. Contact any of these for broad-based questions or referrals.
Administration on Aging
Eldercare Locator
1-800-677-1116
www.aoa.dhhs.gov
www.eldercare.gov
American Geriatrics Society Foundation for Health in Aging
The Empire State Building
350 Fifth Avenue, Suite 801
New York City, NY 10118
1-800-563-4916
www.healthinaging.org
National Association of Area Agencies on Aging
927 15th Street, NW, 6th Floor
Washington, DC 20005
202-296-8130
www.n4a.org
National Council on the Aging
300 D Street, SW, Suite 801
Washington, DC 20024
202-479-1200
www.ncoa.org
National Institute on Aging Information Center
P.O. Box 8057
Gaithersburg, MD 20898-8057
1-800-222-2225
1-800-222-4225 (toll-free TTY)
www.nia.nih.gov
American Healthcare Association (202-842-4444)
The National Council on the Aging, Inc. (202-479-1200)
National Council on Disability
(202-347-1234)
Alzheimer’s Disease
Alzheimer’s Disease Education and Referral Center
P.O. Box 8250
Silver Spring, MD 20907-8250
1-800-438-4380
www.alzheimers.org
Alzheimer’s Association
225 N. Michigan Avenue, Suite 1700
Chicago, IL 60601-7633
1-800-272-3900
www.alz.org
Assisted Living
American Association of Homes and Services for the Aging
2519 Connecticut Avenue, NW
Washington, DC 20008-1520
202-783-2242
www.aahsa.org
Assisted Living Federation of America
11200 Waples Mill Road, Suite 150
Fairfax, VA 22030
1-703-691-8100
www.alfa.org
Care Planner
www.careplanner.org
National Center for Assisted Living
1201 L Street, N.W.
Washington, DC 20005
1-202-824-4444
www.ncal.org
National Citizen's Coalition for Nursing Home Reform
1424 16th Street, NW, Suite 202
Washington, D.C. 20036
202-332-2276
www.nursinghomeaction.org
Caregiving
Children of Aging Parents
P.O. Box 167
Richboro, PA 18954
1-800-227-7294
www.caps4caregivers.org
Family Caregiver Alliance
690 Market Street, Suite 600
San Francisco, CA 94104
415-434-3388
www.caregiver.org
National Alliance for Caregiving
4720 Montgomery Lane, 5th Floor
Bethesda, MD 20814
www.caregiving.org
National Family Caregivers Association
10400 Connecticut Avenue, #500
Kensington, MD 20895-3944
1-800-896-3650
www.nfcacares.org
Well Spouse Foundation
63 W. Main Street, Suite H
Freehold, NJ 07728
1-800-838-0879
www.wellspouse.org
Elder Care Information and Referral Service - For locations of the facility of care in your community
(800-677-1116)
Caregiving Resources
http://www.niapublications.org/tipsheets/carelist.asp
Cincinnati Area Senior Services
http://www.senserv.org/
Council on Aging of Southwestern Ohio
http://www.help4seniors.org/index.htm
Seniors Guide Online
http://www.seniorsguideonline.com
Financial Assistance and Information
American Health Assistance Foundation
22512 Gateway Center Drive
Clarksburg, MD 20871
1-800-437-AHAF (2423)
www.ahaf.org
Center for Medicare and Medicaid Services
7500 Security Building
Baltimore, MD 21244-1850
1-877-267-2323 (toll-free)
1-866-226-1819 (toll-free TTY)
www.medicare.gov
Department of Veterans Affairs
Office of Public Affairs
810 Vermont Avenue, NW
Washington, DC 20420
1-800-827-1000
1-800-829-4833 (toll-free TTY)
www.va.gov
Hill-Burton Free Medical Care Program
Health Resources and Services Administration
Department of Health and Human Services
Division of Facilities Compliance and Recovery
5600 Fishers Lane, Room 10C-16
Rockville, MD 20857
1-800-638-0742
www.hrsa.gov/osp/dfcr/
Employee Benefit Security Administration
Department of Labor
200 Constitution Avenue, NW
Room N5626
Washington, DC 20210
1-866-275-7922
www.dol.gov/ebsa
National Council on the Aging - Benefits Checkup Program
www.benefitscheckup.org
Legal Issues
American Bar Association Commission on Law and Aging
740 15th Street, NW, 8th Floor
Washington, DC 20005
202-662-8690
www.abanet.org/aging
National Academy of Elder Law Attorneys
1604 North Country Club Road
Tucson, AZ 85716
520-881-4005
www.naela.org
National Senior Citizens Law Center
1101 14th Street, NW, Suite 400
Washington, DC 20005
202-289-6976
www.nsclc.org
Meals/Nutrition
American Dietetic Association
120 S. Riverside Plaze, Suite 2000
Chicago, IL 60606-6995
1-800-366-1655 (Consumer Hotline)
www.eatright.org
Meals on Wheels Association of America
1414 Prince Street, Suite 302
Alexandria, VA 22314
703-548-5558
www.mowaa.org
Medication/Prescription Drugs
American Association of Retired Persons - State Pharmacy Assistance Programs
www.aarp.org/bulletin/yourmoney
Food and Drug Administration
5600 Fishers Lane
Rockville, MD 20857
1-888-INFO-FDA (463-6332)
www.fda.gov/cder
National Council on Patient Information and Education
4915 Saint Elmo Avenue, Suite 505
Bethesda, MD 20814-6053
301-656-8565
www.talkaboutrx.org
Pharmaceutical Research and Manufacturers of America - Patient Assistance Programs
www.helpingpatients.org
Respite and Hospice Care
Americans for Better Care of the Dying
4200 Wisconsin Avenue, NW
Washington, DC 20016
202-895-2660
www.abcd-caring.org
National Hospice Foundation
1700 Diagonal Road, Suite 625
Alexandria, VA 22314
1-800-338-8619
www.hospiceinfo.org
Partnership for Caring, Inc./ America’s Voice for the Dying
1620 Eye Street, NW, Suite 202
Washington, DC 20006
1-800-989-9455
www.partnershipforcaring.org
Visiting Nurse Associations of America
99 Summer Street, Suite 1700
Boston, MA 02110
1-888-866-8773
www.vnaa.org