Howstuffworks "Alzheimer's Disease: A Profile of a Brain Disorder"

Alzheimer's disease is a disorder in which there is a steady deterioration of brain function, resulting in progressive loss of memory, recognition, personality, and mental powers. Although Alzheimer's disease may begin as early as age 40, it is most prevalent in the elderly. It accounts for about half of all serious mental impairment in persons over age 65.

Changes in the Brain

In Alzheimer's disease, as in any senile mental disorder, there is atrophy (shrinkage or wasting) of the cerebral cortex (the outer layer of the brain, which is mostly concerned with intellectual and social functioning).

There are also more specific abnormalities, such as the presence of tangles of fibers within the nerve cells and of senile plaques, which are probably deposits of amyloid (a semisolid protein complex seen in many degenerative diseases). These abnormalities are scattered through-out the cortex of a person with Alzheimer's disease; they distinguish the disease from other forms of senility. Because brain biopsy specimens (tissue samples taken from the brain for laboratory examination) are not obtained without very specific reasons and without intention of specific treatment, these abnormalities are usually discovered only after death.

Causes

Theories abound as to the possible causes of Alzheimer's disease. So-called slow viruses (viruses acquired early in life that take many years to do their damage) have been considered, as have environmental factors and damage from previous diseases. Recently, a diminished amount of the enzyme choline acetyltransferase (which is necessary to manufacture the neurotransmitter acetylcholine) has been found in some patients, and theories about replacement of the enzyme or the neurotransmitter are being formulated.

Deficiencies of other neurotransmitters are constantly being discovered. Heredity seems to play some part, since a family history of the disease makes some individuals more likely than others to develop the condition. It is generally agreed that hardening of the arteries is not a cause. Alzheimer's disease does not appear to be contagious, nor is it caused by emotional upsets.

Symptoms

Symptoms vary considerably from one person to another and may occur days or months apart. They begin with small memory lapses, almost always first involving loss of recall for recent events. Such lapses can happen to anyone, but in Alzheimer's disease they grow more serious with time. A person may forget a close relative's name, get lost coming home from the office, forget to turn off the oven, misplace articles, recheck to see if a task was done, or repeatedly ask questions that have already been answered. Eventually, the gaps in memory and the failure to recognize friends and family members will interfere with normal life.

As the disease progresses, the victim of Alzheimer's disease becomes confused, frustrated, and irritable. Although at first the person seems physically unaffected by the disease, as the condition advances, the patient becomes restless, always moving about, and must be watched so that he or she does not wander away or into danger. Endless repetition of unnecessary actions, such as the opening and closing of drawers, is another characteristic symptom of the disease. Some victims of Alzheimer's disease may even become extremely agitated with little or no provocation.

The course of the disease may range from 1 year to as many as 20 years. The disease may eventually result in deterioration of the rest of the nervous system and other parts of the body and in loss of control over bladder and bowels. It may cut life expectancy by contributing to death from another cause, such as pneumonia or heart or kidney failure.

Now that we've covered the causes and symptoms of Alzheimer's, let's look into its diagnosis and treatment in the next section.

Diagnosis and Treatment

Other conditions can cause many of the symptoms of Alzheimer's disease, and many of these conditions are treatable. Therefore, it is very important for the patient to undergo a thorough medical evaluation, which sometimes includes extensive neurologic and psychological examinations and other diagnostic studies, such as computed tomography (a special X-ray technique for obtaining cross-sectional images), electro-encephalography (a study of brain waves), blood tests, and sampling of cerebrospinal fluid.

These procedures can rule out or identify possible causes of nervous system malfunctioning, such as a series of "little strokes," brain tumors or infections, pernicious anemia (which can be cured with vitamin B12), overmedication with barbiturates or bromides, alcohol-ism, the side effects of certain medi-ca-tions, abnormal functioning of the thyroid, or hydrocephalus (block-age of the thyroid, or hydrocephalus (block-age of cerebrospinal fluid in the head).

Problems with memory can also be linked to depression. Depression can be brought on by major life changes, including death of a loved one or moving to a nursing home. Its symptoms, which include apathy, irritation, and poor concentration, are treatable.

Treatment

Medical science does not yet know how to prevent or treat Alzheimer's disease. However, it is important to find a physician who is able to help the patient and the patient's -family handle the many problems that are bound to arise. At times, tranquilizers can lessen agitation and anxiety and reduce the incidence of undesirable behavior. Medication may also help to improve sleeping patterns and treat depression caused by the disease.

It is important that an Alzheimer's patient continue the daily routine, exercise as usual, and keep in touch with friends. Memory aids, such as lists of daily chores, reminders about safety, and a large calendar, can help in day-to-day living. As care of the patient becomes more difficult, it may be best to move the patient to a health care facility where a professional staff can provide around-the-clock care.

Recently, a drug called tacrine was released for the treatment of Alzheimer's disease. This medication appears to improve function in some patients. However, careful monitoring of liver function with frequent blood tests is required, and the drug can have unpleasant side effects. This medication is not a cure, but it does seem to have some beneficial effects. Other drugs, such as donepezil, may also provide some benefit.

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