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 Alzheimer’s, and there is no cure.
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 aging.
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 AD.
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 a diagnosis
- Mental Function Evaluation: Tests of memory, problem solving, attention, and language abilities are common.
- Physical 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 with Alzheimer’s
- Estrogen: This hormone is known to help protect the brain, and some think it could help prevent memory loss.