|Spanish Multimedia Encyclopedia|
Dementia is a loss of brain function that occurs with certain diseases. Alzheimer's disease (AD), is one form of dementia that gradually gets worse over time. It affects memory, thinking, and behavior.
Memory impairment, as well as problems with language, decision-making ability, judgment, and personality, are necessary features for the diagnosis.
Senile dementia - Alzheimer's type (SDAT); SDAT
Age and family history are risk factors for AD.
Other risk factors that are not as well proven include:
There are two types of AD -- early onset and late onset.
The cause of AD is not entirely known, but is thought to include both genetic and environmental factors. A diagnosis of AD is made when certain symptoms are present, and by making sure other causes of dementia are not present.
The only way to know for certain that someone has AD is to examine a sample of their brain tissue after death. The following changes are more common in the brain tissue of people with AD:
When nerve cells (neurons) are destroyed, there is a decrease in the chemicals that help nerve cells send messages to one another (called neurotransmitters). As a result, areas of the brain that normally work together become disconnected.
The buildup of aluminum, lead, mercury, and other substances in the brain is no longer believed to be a cause of AD.
Dementia symptoms include difficulty with many areas of mental function, including:
Dementia usually first appears as forgetfulness.
Mild cognitive impairment is the stage between normal forgetfulness due to aging, and the development of AD. People with MCI have mild problems with thinking and memory that do not interfere with everyday activities. They are often aware of the forgetfulness. Not everyone with MCI develops AD.
Symptoms of MCI include:
The early symptoms of AD can include:
As the AD becomes worse, symptoms are more obvious and interfere with your ability to take care of yourself. Symptoms can include:
People with severe AD can no longer:
Other symptoms that may occur with AD:
AD can often be diagnosed through a history and physical exam by a skilled doctor or nurse. A health care provider will take a history, do a physical exam (including a neurological exam), and perform a mental status examination.
Tests may be ordered to help determine whether other medical problems could be causing dementia or making it worse. These conditions include:
Unfortunately, there is no cure for AD. The goals in treating AD are to:
Most drugs used to treat Alzheimer's are aimed at slowing the rate at which symptoms become worse. The benefit from these drugs is often small, and patients and their families may not always notice much of a change.
Patients and caregivers should ask their doctors the following questions about whether and when to use these drugs:
Two types of medicine are available:
Other medicines may be needed to control aggressive, agitated, or dangerous behaviors. These are usually given in very low doses.
It may be necessary to stop any medications that make confusion worse. Such medicines may include painkillers, cimetidine, central nervous system depressants, antihistamines, sleeping pills, and others. Never change or stop taking any medicines without first talking to your doctor.
Many people take folate (vitamin B9), vitamin B12, and vitamin E. However, there is no strong evidence that taking these vitamins prevents AD or slows the disease once it occurs.
Some people believe that the herb ginkgo biloba prevents or slows the development of dementia. However, high-quality studies have failed to show that this herb lowers the chance of developing dementia. DO NOT use ginkgo if you take blood-thinning medications like warfarin (Coumadin) or a class of antidepressants called monoamine oxidase inhibitors (MAOIs).
If you are considering any drugs or supplements, you should talk to your doctor first. Remember that herbs and supplements available over the counter are NOT regulated by the FDA.
For additional information and resources for people with Alzheimer's disease and their caregivers, see Alzheimer's disease support groups.
How quickly AD gets worse is different for each person. If AD develops quickly, it is more likely to worsen quickly.
Patients with AD often die earlier than normal, although a patient may live anywhere from 3 - 20 years after diagnosis.
The final phase of the disease may last from a few months to several years. During that time, the patient becomes immobile and totally disabled.
Death usually occurs from an infection or a failure of other body systems.
Call your health care provider if someone close to you experiences symptoms of senile dementia/Alzheimer's type.
Call your health care provider if a person with this disorder experiences a sudden change in mental status. (A rapid change may indicate other illness.)
Discuss the situation with your health care provider if you are caring for a person with this disorder and the condition deteriorates to the point where you can no longer care for the person in your home.
Although there is no proven way to prevent AD, there are some practices that may be worth incorporating into your daily routine, particularly if you have a family history of dementia. Talk to your doctor about any of these approaches, especially those that involve taking a medication or supplement.
In addition, early testing of a vaccine against AD is underway.
Aisen PS, Schneider LS, Sano M, Diaz-Arrastia R, van Dyck CH, et al. High-dose B vitamin supplementation and cognitive decline in Alzheimer's disease: a randomized controlled trial. JAMA. 2008;300:1774-1783.
DeKosky ST, Williamson JD, Fitzpatrick AL, Kronmal RA, Ives DG, Saxton JA, et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA. 2008;300:2253-2262.
Burns A, Iliffe S. Alzheimer's disease. BMJ. 2009;338:b158.doi:10.1136.bmj.b158.
Farlow MR, Cummings JL. Effective pharmacologic management of Alzheimer's disease. Am J Med. 2007;120:388-397.