Early detection of patients in the pre demented stage of Alzheimer's disease: the Pre-Al Study.

OBJECTIVES: The aim of the Pre-Al study is to evaluate and compare the predictive value of different tools for an early identification of Alzheimer's disease. DESIGN AND PARTICIPANTS: Patients coming for consultation to memory clinics without dementia were included if they had an objective memory or attention trouble assessed by a MMSE score > 25 (with at least one missing item at the words recall) and / or an Isaac set test score < 28. All were examined by a neuropsychological battery (Free and Cued Selective Reminding Test, digit ordering test, WAIS-R digit symbol, Trail making test, Benton visual retention test, verbal fluency, confrontation naming and Baddeley's double task test). A subpopulation received an MRI and SPECT assessment. RESULTS AND DISCUSSION: 251 patients were included (mean age: 72.0 years; mean education duration: 10.9 years). Validation of the predictive tests will be based on the comparison of these tests in patients developing dementia and others, after a follow-up of at least 3 years. This paper presents methodology of the study and the population description.