Alzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive cognitive, functional, and behavioral impairment. AD is known to have a long pre-symptomatic phase that occurs before the onset of mild cognitive impairment (MCI). During this period, individuals have Alzheimer`s pathology changes in the brain that may eventually progress to a level of severity that induces cognitive, functional, and behavioral changes. Read more:
source