What is Alzheimer's disease?
Alzheimer's disease is the most common form of dementia among older people. Dementia is a brain disorder that seriously affects a person's ability to carry out daily activities. It involves the parts of the brain that control thought, memory, and language. Every day scientists learn more, but right now the causes of Alzheimer's disease are still unknown, and there is no cure.
How many people suffer from the disease?
Scientists think that up to 4 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 Alzheimer's disease, it is much less common.
About 3 percent of men and women ages 65 to 74 have Alzheimer's disease, and nearly half of those age 85 and older may have the disease. It is important to note, however, that Alzheimer's disease is not a normal part of aging.
How did the disease get its name?
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 hallmarks of Alzheimer's disease.
How does the disease affect the brain?
In addition to finding plaques, scientists also have found other brain changes in people with Alzheimer's disease. There is a loss of nerve cells in areas of the brain that are vital to memory and other mental abilities. There also are lower levels of chemicals in the brain that carry complex messages back and forth between nerve cells.
Alzheimer's disease may disrupt normal thinking and memory by blocking these messages between nerve cells.
What are the symptoms?
Alzheimer's disease begins slowly. At first, the only symptom may be mild forgetfulness. People with Alzheimer's disease may have trouble remembering recent events, activities, or the names of familiar people or things. Simple math problems may become hard to solve. 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 Alzheimer's disease or their family members to seek medical help. For example, people in the later stages of Alzheimer's disease 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, understanding, reading, or writing. Later on, people with Alzheimer's disease may become anxious or aggressive, or wander away from home. Eventually, patients need total care.
How is it diagnosed?
An early, accurate diagnosis of Alzheimer's disease 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.
Today, the only definite way to diagnose Alzheimer's disease is to find out whether there are plaques and tangles in brain tissue. To look at brain tissue, doctors must wait until they do an autopsy, which is an examination of the body done after a person dies.
Therefore, doctors must make a diagnosis of "possible" or "probable" Alzheimer's disease. At specialized centers, doctors can diagnose Alzheimer's disease correctly up to 90 percent of the time.
Doctors use several tools to diagnose "probable" Alzheimer's disease: A complete medical history, including information about the person's general health, past medical problems, and any difficulties the person has carrying out daily activities; Also important are medical and neuropsychological tests. Brain scans allow the doctor to look at a picture of the brain to see if anything does not look normal.
The symptoms can be caused by other problems besides Alzheimer's disease. For example, thyroid problems, drug reactions, depression, brain tumors, and blood vessel disease in the brain can cause Alzheimer's-like symptoms. Some of these other conditions can be treated successfully.
What are the treatments for the disease?
No treatment can stop Alzheimer's disease. 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.
Also, some medicines may help control behavioral symptoms of Alzheimer's disease 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 testing two different types of nonsteroidal anti-inflammatory drugs (NSAIDs) to find out if they slow the disease. There is evidence that inflammation in the brain may contribute to Alzheimer's disease damage. Scientists believe that anti-inflammatory drugs such as NSAIDs might help slow the progression of Alzheimer's disease. Rofecoxib (Vioxx) and naproxen (Aleve) are two NSAIDs currently being studied.
Research has shown that vitamin E slows the progress of some consequences of Alzheimer's disease by about 7 months. Scientists now are studying vitamin E to learn whether it can prevent or delay Alzheimer's disease in patients with mild cognitive impairment.
Recent research suggests that ginkgo biloba, an extract made from the leaves of the ginkgo tree, may be of some help in treating Alzheimer's disease symptoms. There is no evidence that ginkgo will cure or prevent Alzheimer's disease. Scientists now are trying to find out whether ginkgo biloba can delay or prevent dementia in older people.
Research also is under way to see if estrogen reduces the risk of Alzheimer's or slows the disease. One study showed that estrogen does not slow the progression of already diagnosed disease, but more research is needed. For example, scientists now are trying to find out whether estrogen can prevent Alzheimer's disease in women with a family history of the disease.
What is MCI?
Recently, 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. Scientists funded by the National Institute on Aging (NIA) are conducting 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.
When does the disease appear?
In most people with Alzheimer's disease, symptoms first appear after age 60. About 3 percent of men and women ages 65 to 74 have the disease, but nearly half of those age 85 and older may have the disease. The average age at diagnosis is about 80. It is not uncommon for individuals to have mild symptoms for some time before a diagnosis is made.
Is misplacing your keys a normal part of aging or could it be a symptom of Alzheimer's disease?
Problems with memory may be due to a variety of factors. It is normal for people of all ages occasionally to forget names, appointments, or the location of objects. Such memory problems may result from stress, distractions, grief, fatigue, poor vision or hearing, use of alcohol, an illness, or trying to remember too many details at once.
Clinical depression may also cause poor concentration, sleep disturbance, or other symptoms that lead to forgetfulness in people who do not have Alzheimer's disease. A decline in short-term memory that sometimes accompanies aging is called age-associated memory loss and does not lead to Alzheimer's disease.
Mild cognitive impairment (MCI) is a change in memory that is different from both Alzheimer's disease and normal age-related memory change. People with MCI have greater than normal age-associated memory problems, but do not have other cognitive losses typical of Alzheimer's such as confusion, attention problems, or difficulty with language.