Elan Corporation

Alzheimer's disease (AD) is a degenerative brain disorder that primarily affects older persons. The concept of mental deterioration (dementia) in older people has been recognized for centuries, and researchers today often point to Shakespeare's King Lear as a classic case study of this disease state. The German psychiatrist, Alois Alzheimer (1864-1915), after whom the disease is named today, first described the clinical syndrome and its histological finding at the turn of the century.

Alzheimer’s disease may begin with simple forgetfulness, but these initial findings inexorably progress to more severe symptoms with increasing cognitive decline. While the time it takes for AD to develop will vary from person to person, more advanced symtoms include confusion, language disturbances, personality and behavior changes, and impaired judgment. Persons with AD may become non-communicative and hostile. As the disease ends its course in profound dementia, patients are unable to care for themselves and often require institutionalization or professional care in the home setting.

While some patients may live up to 20 years after being diagnosed with AD, the average life expectancy after diagnosis is eight years.

According to the Alzhemier's Association, approximately four million people in the United States presently have AD. Most of them are over age 65 and half of all Americans over 85 are thought to have AD. It has been predicted that with our aging population, by the year 2050, there will be more than 14 million people with this disease in the United States.

Alzheimer's disease knows no economic, social or ethnic barriers. This was borne out in recent years with the announcement that former President Ronald Reagan was diagnosed with the disease.

The Alzheimer's Association estimates that the cost of care in a nursing home for one AD patient with severe cognitive impairments, not including losses in productivity or wages, represents an average of $42,000 per year but may exceed $70,000 in some parts of the country. For a disease that can span from two to 20 years, the overall cost of AD to families and society in the U.S. is estimated at $80-100 billion annually. (Estimates as of June 2002.)

Symptoms

The Alzheimer's Association lists ten common warning signs of AD. Taken individually, these signs may mean nothing, but a person who exhibits several of them should see a physician.

• Memory loss that affects work on the job or at home
• Difficulty performing familiar tasks, such as cooking and serving a meal
• Language problems, including forgetting words and garbling sentences
• Getting lost or forgetting what day and time it is
• Judgment, including dress that is noticeably wrong for the weather or the occasion
• Problems with abstract thinking, such as simple addition or subtraction
• Misplacing things, particularly putting objects in totally inappropriate places
• Changes in mood or behavior, particular rapid mood swings that have no apparent cause
• Personality changes, such as heightened anger, suspicion, fear or withdrawal
• Loss of initiative, abandoning familiar interests and pursuits     

Diagnosis

Historically, AD could only be definitively diagnosed upon autopsy after a patient died or by brain biopsy. These methods, which demonstrate the presence of plaques and tangles in the brain, are still considered the gold standard for diagnosis of AD.

Currently, AD is not diagnosed by a single test. A battery of physical, neurological and mental tests are used. In 1996, Elan introduced the ADmark™ Assays, the first Alzheimer's-specific diagnostic tests that identify the genetic marker, ApoE, and measure the biochemical markers, tau and the beta-amyloid peptide, in cerebrospinal fluid. These testing services provide additional specificity in diagnosing a patient's condition.

Treatment

Many drugs are commonly used to treat behavioral symptoms associated with AD. These symptoms include agitation, aggression, paranoia, delusions, or depression associated with AD. Only four drugs known as cholinesterease inhibitors, are available to help improve symptomatic cognitive function in persons diagnosed with AD. These drugs have not been shown to alter the course of the disease. These drugs, Aricept^TM (donezpezil), Cognex^TM (tacrine), Exelon^TM (rivastigmine) and Reminyl^TM (galantamine), act in the same way by increasing brain levels of acetycholine.

Many development compounds are being studied for specific use in helping those who suffer from AD.