P3-287: NEUROPSYCHOLOGICAL FACTORS PREDICTING REVERSION FROM MILD COGNITIVE IMPAIRMENT TO COGNITIVELY NORMAL: 1 YEAR FOLLOW-UP STUDY

Little attention has been given to the meaning of reversion from mild cognitive impairment (MCI) to cognitively normal (CN) and predictive factors associated with such reversion. The purpose of the study was to clarify underlying causes for reversion from MCI to CN and to identify factors associated with reversion. We carefully included 200 individuals with MCI who were likely to be in Alzheimer's disease (AD) spectrum controlling for other etiologies, and reassessed at a subsequent visit about 1.5 year later. All participants underwent comprehensive clinical and neuropsychological assessment. Associated factors with reversion were examined by t-test, χ2 test, and logistic regression. Longitudinal change was examined by a repeated measure ANOVA. Based on the second assessment, 78 (39%) were reverted to CN (rMCI), and 118 (59%) were stayed MCI (sMCI). Four (2%) were progressed to AD and they were excluded in the further analysis. Group difference was significant only in the neuropsychological tests assessing cognitive control ability among a wide range of socio-demographic, clinical, and neuropsychological variables. Both group showed improvement mainly in memory implying practice effect, but rMCI showed much greater improvement. This study preliminary suggest that reversion from MCI to CN might not be a false positive error but a true recovery from cognitive impairment, especially in memory domain. Our results imply that characteristics favorable to restoration of cognitive function may be higher cognitive control ability. Therefore, assessing cognitive control ability might facilitate developing appropriate interventions for MCI as well as prognosis evaluation.