Measurement of progression in Alzheimer's disease: a clinician's perspective

Patients with Alzheimer's disease (AD) and their families must confront two fundamental truths. First, AD is a uniformly progressive disease that ultimately results in debilitating cognitive impairment. Second, although there is now evidence that some medications may produce transient improvement or possibly even slowing of disease progression, there is currently no way to halt the progression of AD. Consequently, patients and their families consistently ask the following questions: 1. What new management issues can be anticipated, and when? 2. What clinical developments are atypical and merit evaluation for a superimposed problem? 3. Is the current treatment working? These questions can only be answered by referring to the natural course of AD, and specifically, information regarding measures of functional impairment and how they change over time. The information that is currently available on this topic is limited and often embodies implicit assumptions that have not been adequately tested. This information will be reviewed, and directions for future research will be outlined.