Predictors of Reversion from Mild Cognitive Impairment to Normal Cognition.

BACKGROUND/AIMS: Few studies have examined predictors of reversion from mild cognitive impairment (MCI) to normal cognition. We sought to identify baseline predictors of reversion, using the National Alzheimer's Coordinating Center Uniform Data Set, by comparing MCI individuals who reverted to normal cognition to those who progressed to dementia. METHODS: Participants (n = 1,208) meeting MCI criteria were evaluated at the baseline visit and 3 subsequent annual visits. Clusters of baseline predictors of MCI reversion included demographic/genetic data, global functioning, neuropsychological functioning, medical health/dementia risk score, and neuropsychiatric symptoms. Stepwise logistic regression models identified predictors of MCI reversion per cluster, which were then entered into a final comprehensive model to find overall predictor(s). RESULTS: At 2 years, 175 (14%) reverted to normal cognition, 612 (51%) remained MCI, and 421 (35%) progressed to dementia, with sustained diagnoses at 3 years. Significant variables associated with MCI reversion were younger age, being unmarried, absence of APOE ε4 allele, lower CDR-SOB score, and higher memory/language test scores. CONCLUSION: A relatively sizable proportion of MCI individuals reverted to normal cognition, which is associated with multiple factors previously noted. Findings may enhance MCI prognostic accuracy and increase precision of early intervention studies of dementia.

Does mild cognitive impairment always lead to dementia? A review.

Mild cognitive impairment (MCI) has often been studied in its association with dementia, yet higher rates of reversion to normal cognition than progression to dementia suggest that MCI does not necessarily lead to dementia. Compared to the numerous studies on MCI progression, relatively few have examined reversion. This paper highlights the current literature on characteristics and predictive factors of MCI reversion, along with an overview of studies on MCI patients who remain diagnostically stable (i.e., MCI stability). Of the available studies, predictors of reversion have been noted in areas of cognitive/global functioning, demographic/genetic/biomarker data, and personality/lifestyle factors. However, there is a need for increased study of MCI reversion, considering that patients in this group can fluctuate between different trajectories of MCI (e.g., normal cognition back to MCI or even progression to dementia) within a given follow-up time period. Further examination of reversion via a longitudinal, multifactorial approach would better inform clinicians regarding the likelihood of reversion amongst MCI patients and subsequently modify treatment methods accordingly. Furthermore, researchers would have greater power in detecting treatment effects in their clinical intervention studies of early dementia by improving selection criteria to exclude MCI participants who are more likely to revert and remain cognitively normal than progress to a dementia.