The Fate of the 0.5s: Predictors of 2-Year Outcome in Mild Cognitive Impairment

Abstract

Impairments in executive cognition (EC) may be predictive of incident dementia in patients with mild cognitive impairment (MCI). The present study examined whether specific EC tests could predict which MCI individuals progress from a Clinical Dementia Rating (CDR) score of 0.5 to a score Z1 over a 2-year period. Eighteen clinical and experimental EC measures were administered at baseline to 104 MCI patients (amnestic and non-amnestic, single-and multiple-domain) recruited from clinical and research settings. Demographic characteristics, screening cognitive measures and measures of everyday functioning at baseline were also considered as potential predictors. Over the 2-year period, 18% of the MCI individuals progressed to CDR Z 1, 73.1% remained stable (CDR 5 0.5), and 4.5% reverted to normal (CDR 5 0). Multiple-domain MCI participants had higher rates of progression to dementia than single-domain, but amnestic and non-amnestic MCIs had similar rates of conversion. Only three EC measures were predictive of subsequent cognitive and functional decline at the univariate level, but they failed to independently predict progression to dementia after adjusting for demographic, other cognitive characteristics, and measures of everyday functioning. Decline over 2 years was best predicted by informant ratings of subtle functional impairments and lower baseline scores on memory, category fluency, and constructional praxis. (JINS, 2011, 17, 277-288)

Frailty and cognitive impairment among community-dwelling elderly

“…However, studies with a longer follow-up period report a longitudinal association between frailty and the incidence of both mild cognitive impairment 7 and dementia 5,6 . It is therefore likely that the follow-up period in the present study was not long enough to demonstrate an association because the progression to cognitive impairment is quite heterogeneous among individuals [9][10][11]29 . Another factor that may have affected this result was the fact that the present study only investigated the incidence of a positive screening for cognitive impairment and not the occurrence of better established cognitive alterations, such as mild cognitive impairment and dementia [5][6][7] .…”

“…Moreover, older adults with cognitive impairment progress to more severe stages on an annual basis and the conversion rate to dementia can reach 10 to 30% a year 10,11 . However, there is little knowledge on the factors related to progressive cognitive impairment within a one-year period and whether this progression is associated with frailty.…”

Reaffirmed Limitations of Meta-Analytic Methods in the Study of Mild Traumatic Brain Injury: A Response to Rohling et al.

“…Regardless of the type of neurological and/or neuropsychiatric disorder, neuropsychological assessment faces its biggest challenge in detecting subtle impairment (Aretouli, Okonkwo, Samek, & Brandt, 2011;Duff, Hobson, Beglinger, & O'Bryant, 2010). Based on Rohling et al's conclusions, mTBI alters acute (within 30 days) neurocognitive abilities, with an underlying assumption that neuropsychological testing methods are, in fact, sensitive in detecting the acute deficits.…”

Prospective Memory Impairment in Mild Cognitive Impairment: An Analytical Review

“…Depending on length of follow-up, the rate of conversion to dementia was about 25% in single domain aMCI but it ranged between 54% and 77% in multiple domain aMCI (Bozoki et al 2001;Alexopoulos et al 2006). Moreover, likely indicating reduced conversion detection sensitivity in the amnesticonly subtype and tendency for isolated memory problems to be secondary to a host of temporary or psychiatric conditions, in single domain MCI (both amnestic and nonamnestic subtypes) a return to normal state is more frequently observed (Aretouli et al 2011;Forlenza et al 2009). Some authors also suggested that multiple domain aMCI may have a greater likelihood of representing a mixture of AD and other dementia-related pathologies (Petersen and Negash 2008).Unfortunately, studies that tried to confirm the predictive value of MCI subtype classification in the subsequent development of full-blown dementia reached inconsistent results.…”