Does mild cognitive impairment always lead to dementia? A review

Abstract

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.

Keywords: Alzheimer's disease; Dementia; Mild cognitive impairment; Neuropsychology; Reversion; Stability.