Dementia

Dementia causes progressive and irreversible impairment in several areas of intellectual function including memory, visuospatial skills, language, executive skills (e.g. ability to organize, plan, and to think abstractly), and mood/personality. Dementia can result from more than 70 disorders including toxicity (e.g., medications, alcoholism), trauma, infection (e.g., AIDS), metabolic disorders, nutritional deficiencies (e.g., B12 deficiency), vascular (multi-infarct dementia), tumors (meningioma), and degenerative conditions (e.g., Alzheimer's disease, Parkinson's disease). In older adults the most common causes of dementia's are: Alzheimer's disease (AD) (50 to 60%); multi-infarct dementia (MID) (10 to 15%); and metabolic-related dementia's (e.g,. alcohol, medications) (5 to 10%). Usually the onset of dementia is gradual, although it may occur suddenly (i.e. stroke or trauma). People with dementia are often unaware of their increasingly impaired intellectual function.

The prevalence of dementia increases with age and affects an estimated 5 percent of persons age 65 and older. The fastest growing segment of the older population, those age 75 and older have the highest rates of dementia. As the size of the older population continues to increase, dementia is becoming a major public health issue. The burden of dementia imposes substantial social, economic and psychological costs on families and patients. By 2040, dementia will affect an estimated 11.8 million Americans (Evans, 1990).

Dementia is not the only source of cognitive impairment in older adults. It must be distinguished from other conditions, such as delirium or major depression, in order to determine the appropriate treatment. Delirium is characterized by a rapid onset of symptoms, marked fluctuations in cognition that cause primarily deficits in attention, and perceptual abnormalities such as visual hallucinations. People with major depression may appear cognitively impaired because of poor concentration and low energy. Depression can be distinguished from dementia because the symptoms are not progressive, language remains intact, and affect (i.e., mood/thoughts) are so pervasively negative.

Distinguishing Between Delirium and Dementia