Reversion From Mild Cognitive Impairment to Normal Cognition

Abstract

The initiation of Alzheimer disease (AD) prevention studies has placed greater emphasis on the need to accurately detect individuals with amnestic mild cognitive impairment (aMCI) given their increased risk for developing AD. Several studies reporting on the incidence and prevalence of aMCI have also found that a substantial number of aMCI cases at baseline assessments revert to normal cognition at subsequent assessments. This instability presents a major challenge to intervention studies aimed at preventing the onset of clinical symptoms associated with aMCI. Reversion rates from 25 studies were used for this meta-analysis which found an overall reversion rate of approximately 24%. When the studies were separated by their setting (community vs. clinic), substantial differences in reversion rates were noted with clinic-based studies having a much lower reversion rate (14%) than community-based studies (31%). North American and European studies had high heterogeneity of reversion rates, whereas Asian studies had moderate levels of heterogeneity and significantly lower rates of reversion. Continued improvement in diagnostic and classification methodologies may help in more accurately identifying aMCI cases which are less likely to revert to normal cognition.

Resting‐state network dysfunction in Alzheimer's disease: A systematic review and meta‐analysis

“…The modest findings of our present meta-analysis may be because of a lack of statistical power from having multiple, small, single-site samples. Clinical heterogeneity might also have played a role, that is, only a subset of MCI patients develop AD dementia [6], [25], and there may be pathologic subtypes [26]. We also demonstrated DMN hyperconnectivity in MCI and ADMCI using network-level statistics.…”

Assessment of Driving Safety in Older Adults with Mild Cognitive Impairment

“…We recommend that on-road driving performance and validated tests of driving skills be the key focus of driving assessments. In addition, the stability of MCI diagnosis over time is well known to be low, with around 24% of MCI reverting to normal at follow-up [39]. Thus, diagnoses of mild cognitive disorders are unsuitable for guiding major decisions regarding license cancellation that have lasting impacts on patient independence.…”

Communicating mild cognitive impairment diagnoses with and without amyloid imaging

“…Persons with MCI progress to dementia at a rate of 12–16% per year [7]. Long-term studies, however, show that a significant proportion of MCI patients do not progress to dementia and a subset may revert to normal cognition [8, 9]. These data foster criticism of the MCI diagnosis as enmeshed with ambiguity and uncertainty and therefore a cause of unnecessary worry [6].…”