Alzheimer's disease (AD) is a progressive, neurodegenerative disease characterized in the brain by abnormal clumps (amyloid plaques) and tangled bundles of fibers (neurofibrillary tangles) composed of misplaced proteins. Age is the most important risk factor for AD; the number of people with the disease doubles every 5 years beyond age 65. Three genes have been discovered that cause early onset (familial) AD. Other genetic mutations that cause excessive accumulation of amyloid protein are associated with age-related (sporadic) AD. Symptoms of AD include memory loss, language deterioration, impaired ability to mentally manipulate visual information, poor judgment, confusion, restlessness, and mood swings. Eventually AD destroys cognition, personality, and the ability to function. The early symptoms of AD, which include forgetfulness and loss of concentration, are often missed because they resemble natural signs of aging.
There is no cure for AD and no way to slow the progression of the disease. For some people in the early or middle stages of AD, medication such as tacrine (Cognex) may alleviate some cognitive symptoms. Donepezil (Aricept), rivastigmine (Exelon), and galantamine (Reminyl) may keep some symptoms from becoming worse for a limited time. A fifth drug, memantine (Namenda), was recently approved for use in the United States. Combining memantine with other AD drugs may be more effective than any single therapy. One controlled clinical trial found that patients receiving donepezil plus memantine had better cognition and other functions than patients receiving donepezil alone. Also, other medications may help control behavioral symptoms such as sleeplessness, agitation, wandering, anxiety, and depression.
AD is a progressive disease, but its course can vary from 5 to 20 years. The most common cause of death in AD patients is infection.
The NINDS conducts and supports research on neurodegenerative and dementing disorders, including AD. Scientists are currently studying or testing different types of drugs and other substances to determine if they can stop AD progression, including nonsteroidal anti-inflammatory drugs (NSAIDS), statins (such as those used for lowering cholesterol), folic acid, gingko biloba, and vitamins E, B6, and B12. Studies in basic science are also exploring the potential of vaccines. The National Institute on Aging and the National Institute of Mental Health also support research related to AD.
Although Alzheimer's Disease itself is not a qualifying diagnosis for rehabilitation, we have found that many of our patients have the disease along with their primary illness or disability. Therefore, it is important that the patient, the caregiver, and the therapy team be aware of the disease process and its implications for therapy.