Four-year outcome of mild cognitive impairment: The contribution of executive dysfunction.

Abstract

Objective The contribution of executive cognition (EC) to the prediction of incident dementia remains unclear. This prospective study examined the predictive value of EC for subsequent cognitive decline in persons with mild cognitive impairment (MCI) over a 4-year period. Methods 141 persons with MCI (amnestic and non-amnestic, single- and multiple-domain) received a baseline and two biennial follow-up assessments. Eighteen tests, assessing six different aspects of EC, were administered at baseline and at 2-year follow-up, together with screening cognitive and daily functioning measures. Longitudinal logistic regression models and generalized estimating equations (GEE) were used to examine whether EC could predict progression to a Clinical Dementia Rating Scale (CDR) score of 1 or more over the 4-year period, first at the univariate level and then in the context of demographic and clinical characteristics, daily functioning measures and other neurocognitive factors. Results Over the 4-year period, 56% of MCI patients remained stable, 35% progressed to CDR≥1, and 8% reverted to normal (CDR=0). Amnestic MCI subtypes were not associated with higher rates of progression to dementia, whereas subtypes with multiple impairments were so associated. Eight out of the 18 EC measures, including all three measures assessing inhibition of prepotent responses, predicted MCI outcome at the univariate level. However, the multivariate GEE model indicated that age, daily functioning, and overall cognitive functioning best predicted progression to dementia. Conclusion Measures of EC (i.e., inhibitory control) are associated with MCI outcome. However, age and global measures of cognitive and functional impairment are better predictors of incident dementia.

Reversion From Mild Cognitive Impairment to Normal Cognition

“…The vast majority of the studies had higher proportions of females, both in the total samples and within the aMCI groups, while the age at baseline for aMCI cases in most of the studies was between 70 and 79 with an average of approximately 75. 9,10,13,15,[18][19][20][22][23][24][26][27][28][29][30][31][32]34,35 The extent to which these demographic factors contributed to the observed heterogeneity of this study is unclear; however, studies with older individuals are likely to see lower reversion rates as both age-related cognitive decline and the risk for developing AD both increase with age. The heterogeneity among studies may also be associated with their respective attrition rates.…”

Frequent Mild Cognitive Deficits in Several Functional Domains in Elderly Patients With Heart Failure Without Known Cognitive Disorders

“…13,17 Others have found similar conversion rates in aMCI-MD and naMCI-MD. 18 Results from some studies indicate that patients with MCI and impairment in $2 cognitive domains are at the highest risk of developing dementia. 10,18 Recently, studies on the occurrence of MCI in HF have been published.…”

“…18 Results from some studies indicate that patients with MCI and impairment in $2 cognitive domains are at the highest risk of developing dementia. 10,18 Recently, studies on the occurrence of MCI in HF have been published. In one study, the Montreal Cognitive Assessment (MoCA) 19 was used to identify MCI: 22% of HF patients fulfilled criteria for MCI.…”

Scores Obtained from a Simple Cognitive Test of Visuospatial Episodic Memory Performed Decades before Death Are Associated with the Ultimate Presence of Alzheimer Disease Pathology

“…Measures of executive function, assessed over a 4-year period, predicted the conversion of mild cognitive impairment (MCI) to dementia [6], and scores from tests of episodic, working and semantic memory predicted a similar conversion over a 5-year period [7]. Longer-term studies have shown that changes in scores examining global cognitive function, as measured by the Mini-Mental State Examination (MMSE), visuospatial memory and verbal fluency can predict clinical AD 9 years before diagnosis [8], and decreased scores of semantic memory and conceptual formation are predictive of dementia 12 years before symptoms [9].…”