What is Dementia?

The term dementia refers to symptoms of persisting cognitive (intellectual or mental) deterioration severe enough to interfere substantially with daily activities. People with dementia almost always have a great deal of trouble learning or recalling events or new information. Most also have other cognitive difficulties affecting speech and language, visual-spatial abilities (for example, becoming disoriented or easily lost), emotion and personality, or reasoning and judgment.

Cognitive abilities change over the course of a life span, but for most mental tasks, healthy older people will perform about as well as other adults. Importantly, dementia is not the inevitable consequence of aging, and most elderly can expect to remain intellectually vigorous into late old age. Forgetting where one has parked the car or forgetting names of acquaintances does not indicate dementia. However, it is imperative that anyone with significant cognitive impairment seek medical evaluation.

What Can Cause Dementia?

Dementia by itself is not a diagnosis. A large number of illnesses cause dementia, and it is important that a medical evaluation be done to seek a specific diagnosis. A diagnosis is important because many causes of dementia can be treated; some forms are completely curable. Diagnostic information also helps the physician to formulate a prognosis and to suggest medications and other interventions most likely to be of benefit.

The most common cause of dementia is Alzheimer's disease, which accounts for well over half of all cases. Alzheimer's symptoms usually begin gradually, and deficits progress slowly over a course that can last ten years or longer. The most prominent symptom is usually the loss of a type of memory sometimes referred to as "new learning." Early on, an Alzheimer's patient may well be able to recall events from years ago but not be able what someone said a few days, or even a few minutes, before. Although there is not yet a cure for Alzheimer's disease, newer medications sometimes help Alzheimer's symptoms. Doctors are increasingly accurate in diagnosing Alzheimer's disease, but a definite diagnosis is possible only with a microscopic examination of brain tissues obtained at the time of death.

A second common form of dementia is due to stroke, usually the accumulation of multiple small strokes. This diagnosis is made on the basis of the neurological examination and the brain scan. Other dementia diagnoses are less common, but many of these causes of dementia have good treatments available and must be specifically considered by the physician.

What does the doctor look for during an evaluation for dementia?

Although the neurologist is the medical specialist most familiar with different varieties of dementia, dementia can also be properly evaluated and managed by other medical specialists. During a patient's life, there is no specific diagnostic test for Alzheimer's disease. Other causes of dementia can be suspected and diagnosed on the basis of a careful medical history, a physical examination that includes a detailed neurological assessment, a separate evaluation of the patient's cognitive abilities (sometimes a psychologist is consulted for this purpose), and laboratory tests. Laboratory tests are tailored to the individual patient but usually include blood tests and a brain scan.  

After a diagnosis: what happens next?

Knowing a patient's diagnosis will help guide the physician, patient, and family in answering a number of important questions. Will symptoms worsen with time, and if so, how rapidly? What types of problems are the patient and caregiver likely to face? What medications may help and what medications are unlikely to help? Are there medical specialists who might be consulted for additional advice or for a second opinion? Is the dementia hereditary? Should driving or other activities be restricted? (Since 1988, California physicians have been required by law to report demented individuals to the local health department; these patients may then be asked to undergo a driving assessment by the Department of Motor Vehicles.) What community resources are available for patients or for their caregivers? Are respite services, daycare facilities, board-and-care homes, or skilled nursing facilities appropriate alternatives, and if so, how does one find out about these? What are the legal consequences of a person becoming incompetent to make medical, financial, and other decisions for himself? The patient's physician will be able to answer many of these questions, but additional help is often forthcoming from other agencies. For Los Angeles residents, the Los Angeles chapter of the Alzheimer's Association is an especially helpful place to begin.

Many families may wish to consider an autopsy for a definitive diagnosis at the time of death, especially for disorders such as Alzheimer's disease where a firm diagnosis is not possible during life. For example, a major research-based autopsy program is administered under the auspices of the Alzheimer's Disease Research Center at the University of Southern California. In general, autopsy arrangements should be made well in advance of any terminal illness.

For interested patients and families, there are a number of thoughtful scientifically worthy research programs for demented patients and (for purposes of comparison) healthy older adults without dementia. Some research might possibly benefit the patient or family directly (new diagnostic tests, experimental drugs, innovative ways helping family members cope with the stress of caring for a demented relative). Other projects will assist physicians and other scientists learn more about aging and dementia and are therefore more likely to help future dementia victims; even here, however, patients and families often benefit indirectly in a variety of meaningful ways.

It is estimated that annual patient care costs for Alzheimer's disease are a thousand times greater than money actually expended for research on this devastating disorder. It is crucial that patients and their families inform their elected representatives of the vital need to support clinical and laboratory research into the cause and effective treatment of dementing illnesses.

[This information was modified from a chapter by Dr. Victor Henderson entitled, "What is Dementia?" The original chapter appeared in a book edited by S. Slesinger called: Elder Services: The Los Angeles County Guide and was published in Phoenix, Arizona, by the Oryx Press in 1992.]