Clinical Stages of Alzheimer's Disease
Alzheimer's disease is progressive, which means that symptoms worsen over time. How fast the disease progresses, and what pattern symptoms might follow, is variable by individual.
Researchers and doctors use a number of scales to measure the progression of symptoms over time, which may define as many as seven distinct stages of the disease. For general purposes, three broad phases are typically recognized: mild, moderate and severe.
New York University's Dr. Barry Reisberg outlines the seven major clinical stages of Alzheimer's disease. Dr. Reisberg is the Clinical Director of the Fisher Alzheimer’s Disease Education and Resources Program at the New York University Langone Medical Center. As the principal investigator of studies conducted by the National Institutes of Health, Dr. Reisberg's work has been pivotal in the development of two of the three current pharmaceutical treatment modalities for Alzheimer's. His rating scales and descriptions of the nature and course of Alzheimer's are widely used throughout the world.
Dr. Barry Reisberg coined the term Mild Cognitive Impairment.
What Is Mild Cognitive Impairment?
Mild Cognitive Impairment, or MCI, is increasingly being used to describe a syndrome of memory impairment that does NOT significantly impact daily activities and is not accompanied by declines in overall cognitive function. Researchers have found that 6 percent to 25 percent of people with MCI progress to Alzheimer's, which has raised questions about whether MCI might represent some kind of "transitional stage" between normal aging and dementia. In fact, many experts believe that MCI, as well as age-related memory loss, may always be an early form of Alzheimer's, and progression to symptomatic Alzheimer's disease may be only a matter of time. In some people, the progression may be very slow, so the person may die of other causes before displaying the full spectrum of Alzheimer's symptoms. MCI is now recognized as a clinical condition that requires ongoing assessment and possibly treatment to delay its progression.
“Outcome Over Seven Years of Healthy Adults With and Without Subjective Cognitive Impairment” by Dr. Barry Reisberg. This January 2010 finding, and data collection that spanned over two decades, reveals that healthy older adults with subjective memory loss are 4.5 times more likely to develop mild cognitive impairment and dementia.