A FOLLOW-UP-STUDY OF AGE-ASSOCIATED MEMORY IMPAIRMENT - NEUROPSYCHOLOGICAL PREDICTORS OF DEMENTIA

OBJECTIVE: To examine the clinical course of age-associated memory imp airment (AAMI) and to evaluate the value of neuropsychological tests i n predicting cognitive decline in AAMI subjects in a follow-up period of more than 3 years. DESIGN: Prospective cohort study. SETTING: The o utpatient Memory Research Unit of the Department of Neurology at the U niversity of Kuopio in Eastern Finland. PARTICIPANTS: A sample of 229 subjects (mean age 71.7 years) identified in two screening studies as having AAMI. MEASUREMENTS: A battery of neuropsychological tests and a : structured inquiry for health status and subjective memory complaint s were performed at baseline and follow-up to diagnose AAMI according to the criteria proposed by a National Institute of Mental Health work group. RESULTS: Of the 229 subjects, 176 (76.9%) participated in the follow-up for, on average, 3.6 years after the baseline. Of the partic ipants, 104 (59.1%) still met the AAMI criteria. Other subjects were c lassified into five subgroups: (1) subjects showing decline in cogniti on meeting dementia diagnosis (16, 9.1% (13 of them AD)); (2) subjects with mild cognitive decline meeting neither dementia nor AAMI criteri a (13, 7.4%); (3) subjects with memory performance now superior to AAM I criteria (17, 9.7%); (4) subjects having a disease classified as exc lusion in the criteria (15, 8.5%); (5) subjects not now reporting subj ective memory loss in everyday life (9, 5.1%). Two subjects (1.1%) wer e not classified because of incomplete data. Neuropsychological tests predicted which subjects would develop dementia during the follow-up p eriod. The best discriminators between these subjects and those who re mained AAMI were memory and verbal fluency tests. CONCLUSION: The stud y suggests that, in general, AAMI is nonprogressive, but the AAMI popu lation also includes subjects with early dementia and subjects without genuine memory loss, However, these subjects can be differentiated wi th a more detailed neuropsychological evaluation.