Alzheimer’s Disease (AD) is an irreversible neurodegenerative disease which results in a loss of mental functions due to the deterioration of brain tissue. As the disease progresses it robs those who have it of their memory, and eventually, overall mental and physical function, leading to death. It is the most common cause of dementia among people over the age of 65, affecting an estimated 4.5 million Americans.
During the past 20 years, considerable new information has been obtained concerning the factors responsible for AD, leading to development of new treatments. Extensive clinical studies have characterized the time course of many cognitive and behavioral measures, and have correlated clinical data with autopsy findings.
Read the Article "Searching for the Biomarkers of Alzheimer's".
Mild Cognitive Impairment (MCI) differs from both AD and normal age-related memory change. People with MCI have ongoing memory problems but not to the point where their impairment interferes significantly with daily activities.
While MCI is an important group of subjects to study, the topic is not without controversy. One issue that is critical to the goals of the ADNI concerns the specific criteria to be used for defining MCI. The criteria are as follows: 1) memory complaint, preferably corroborated by an informant, 2) memory impairment relative to the appropriate reference group, 3) essentially normal general cognitive function, 4) largely preserved activities of daily living, and 5) not demented.
In selecting specific criteria for the ADNI, one needs to be mindful of the intended purpose of the study. Since this project is primarily concerned with developing imaging measures and biomarkers for incipient AD, the appropriate subtype of MCI which likely represents prodromal AD should be emphasized. |
