Clinical utility of the cogstate brief battery in identifying cognitive impairment in mild cognitive impairment and Alzheimer’s disease

Abstract

BackgroundPrevious studies have demonstrated the utility and sensitivity of the CogState Brief Battery (CBB) in detecting cognitive impairment in Alzheimer’s disease (AD) and mild cognitive impairment (MCI) and in assessing cognitive changes in the preclinical stages of AD. Thus, the CBB may be a useful screening tool to assist in the management of cognitive function in clinical settings. In this study, we aimed to determine the utility of the CBB in identifying the nature and magnitude of cognitive impairments in MCI and AD.MethodsHealthy adults (n = 653) adults with amnestic MCI (n = 107), and adults with AD (n = 44) who completed the CBB participated in this study. Composite Psychomotor/Attention and Learning/Working Memory scores were computed from the individual CBB tests. Differences in composite scores were then examined between the three groups; and sensitivity and specificity analyses were conducted to determine cut scores for the composite scores that were optimal in identifying MCI- and AD-related cognitive impairment.ResultsLarge magnitude impairments in MCI (g = 2.2) and AD (g = 3.3) were identified for the learning/working memory composite, and smaller impairments were observed for the attention/psychomotor composite (g’s = 0.5 and 1, respectively). The cut-score associated with optimal sensitivity and specificity in identifying MCI-related cognitive impairment on the learning/working memory composite was -1SD, and in the AD group, this optimal value was -1.7SD. Both composite scores showed high test-retest reliability (r = 0.95) over four months. Poorer performance on the memory composite was also associated with worse performance on the Mini Mental State Exam and increasing severity on the Clinical Dementia Rating Scale sum of boxes score.ConclusionsResults of this study suggest that the CogState learning/working memory composite score is reduced significantly in CI and AD, correlate well with measures of disease classification and are useful in identifying memory impairment related to MCI- and AD.

APOE ε4 moderates amyloid-related memory decline in preclinical Alzheimer's disease

“…Although smaller effects of 34 carriage on Ab-related cognitive decline were observed for attention and psychomotor function, no statistically significant effect of 34 carriage was evident for Ab-related rates of change on the CDR sum of boxes or MMSE. These data show that even with the larger sample size, these instruments do not have sufficient sensitivity to detect the cognitive effects of 34 in Abþ older adults (Table 1) (Gomar et al, 2014;Lim et al, 2013;Okonkwo et al, 2014) most likely because cognitively normal adults continue perform at, or around, ceiling levels. This characteristic also means that data distributions for both instruments do not meet necessary statistical assumptions for parametric data analyses (e.g., normality and equality of variance), thus limiting further their utility for characterizing cognitive change preclinical AD.…”

“…The current finding that APOE 34 increased Ab-related memory decline is consistent with the interactions between 34 and Ab on memory observed in cross-sectional studies. For example, although large cross-sectional studies of preclinical AD find that high Ab is not associated with cognitive impairment (Doraiswamy et al, 2012;Lim et al, 2013), Ab burden is associated weakly with memory performance when samples are limited to Abþ individuals who also carry the APOE 34 allele (Kantarci et al, 2012;Lim et al, 2013). Taken together, these data do suggest that 34 does influence the effects of Ab on cognition, although the nature of this effect is relatively subtle and seen most clearly from prospective study of relatively large samples of Abþ individuals.…”

“…Two composite scores were also constructed from these measures, namely the psychomotor/attention (DETIDN) composite and the learning/working memory (OCLOBK) composite (Lim et al, 2012;Maruff et al, 2013). The Mini Mental State Examination (MMSE), the Clinical Dementia Rating (CDR) Scale, and delayed recall of the Logical Memory test were also administered at each assessment.…”

“…Cognition was measured using 4 computerized tests from the Cogstate Brief Battery that have been demonstrated to be sensitive and specific to Ab-related decline and in identifying MCI-and AD-related cognitive impairment in the AIBL cohort (Lim et al, 2012;Maruff et al, 2013); these tests included detection (psychomotor speed), identification (attention), one card learning (visual learning), and one back ( working memory). Two composite scores were also constructed from these measures, namely the psychomotor/attention (DETIDN) composite and the learning/working memory (OCLOBK) composite (Lim et al, 2012;Maruff et al, 2013).…”

Safety and clinical effects of EVP-6124 in subjects with Alzheimer's disease currently or previously receiving an acetylcholinesterase inhibitor medication

“…For example, a pool of 12 randomized trials comparing donepezil with placebo showed a mean difference of À1.969 at 12 weeks and À2.895 at 24 weeks [48]. The CogState computerized cognitive testing is a more recent tool which consists of four cognitive tasks involving playing cards [49,50]. In this battery of tests, the test taker is provided instructions on a computer screen and responds using a computer keyboard with a 'yes' or 'no' answer based on a certain rule.…”