Long-term observation of a multicomponent cognitive intervention in amnestic mild cognitive impairment (aMCI)

Abstract

Recent studies demonstrated benefits through cognitive intervention (CI) in subjects with amnestic mild cognitive impairment (aMCI). However, few studies determined long-term effects, conversion rate of MCI-subjects into AD, and the role of early intervention. We evaluated a long-term observation of an early and 8-month time-lagged multicomponent CI on subjects with aMCI with follow-up assessments up to 24 months. Primary outcome were changes in global cognitive functions (Alzheimer's Disease Assessment Scale, ADAS-cog, and Mini Mental Status Examination, MMSE), secondary outcome were change in specific cognitive and non-cognitive functions and conversion into AD. 24 aMCI-subjects were randomly assigned to a 6-months CI (n = 12) and an active control condition (n = 12). Following the control condition participants attended to the CI with 8-month time-lag (IG 2) compared to early intervention (IG 1). 18 participants completed the study after 24 months. Data of 1- and 2-year follow-up revealed a stable intervention-effect on the primary outcome ADAS-cog in the IG 1 (p = .024). Compared to early beginners, IG 2 seemed to benefit from CI to a lesser extent. Only participants of the IG 2 (6 of 12) converted into AD. Cognitive benefits of the CI on global cognitive status appear to be preserved over extended follow-up periods. Early CI may be able to delay conversion to AD. Findings in a small sample of subjects encourage the use of the CI in larger scales studies to confirm effects.