[A critical review of available tools for evaluating memory enhancers in Alzheimer's disease]

The study reviews critically the neuropsychological measurement tools available to assess the efficacy of potential memory enhancers in patients with Alzheimer's disease (AD). A review of some concepts concerning the characteristics of memory impairment in AD patients and of problems related to the selection of a study population provides a framework for this analysis. The tools available for efficacy evaluations are then classified according to their conceptual and formal characteristics: psychometric tests, rating scales and clinician global assessment tools. In each category the instruments were assessed according to several criteria: construct and ecological validity; sensitivity to changes in symptomatology; inter-rater reliability and the reliability of equivalent forms; feasibility for use with AD patients, especially brevity, to encourage their cooperation. Examining advantages, drawbacks and limitations of instruments in each category yields two conclusions: no single instrument scale or test battery fills all the criteria for a clinical trial, but these imperfect instruments are complementary. Accordingly, a battery including the three categories of instruments and allowing for investigation of the different memory systems has been proposed.