scholarly journals Cognitive Function during the Prodromal Stage of Alzheimer’s Disease in Down Syndrome: Comparing Models

2021 ◽  
Vol 11 (9) ◽  
pp. 1220
Author(s):  
Christy L. Hom ◽  
Katharine A. Kirby ◽  
Joni Ricks-Oddie ◽  
David B. Keator ◽  
Sharon J. Krinsky-McHale ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down Syndrome ◽  
Executive Function ◽  
Cognitive Function ◽  
Intellectual Disabilities ◽  
Cognitive Domain ◽  
Equation Modeling ◽  
High Risk Population ◽  
Prodromal Stage

Accurate identification of the prodromal stage of Alzheimer’s disease (AD), known as mild cognitive impairment (MCI), in adults with Down syndrome (MCI-DS) has been challenging because there are no established diagnostic criteria that can be applied for people with lifelong intellectual disabilities (ID). As such, the sequence of cognitive decline in adults with DS has been difficult to ascertain, and it is possible that domain constructs characterizing cognitive function in neurotypical adults do not generalize to this high-risk population. The present study examined associations among multiple measures of cognitive function in adults with DS, either prior to or during the prodromal stage of AD to determine, through multiple statistical techniques, the measures that reflected the same underlying domains of processing. Participants included 144 adults with DS 40–82 years of age, all enrolled in a larger, multidisciplinary study examining biomarkers of AD in adults with DS. All participants had mild or moderate lifelong intellectual disabilities. Overall AD-related clinical status was rated for each individual during a personalized consensus conference that considered performance as well as health status, with 103 participants considered cognitively stable (CS) and 41 to have MCI-DS. Analyses of 17 variables derived from 10 tests of cognition indicated that performance reflected three underlying factors: language/executive function, memory, and visuomotor. All three domain composite scores significantly predicted MCI-DS status. Based upon path modeling, the language/executive function composite score was the most affected by prodromal AD. However, based upon structural equation modeling, tests assessing the latent construct of memory were the most impacted, followed by those assessing visuomotor, and then those assessing language/executive function. Our study provides clear evidence that cognitive functioning in older adults with DS can be characterized at the cognitive domain level, but the statistical methods selected and the inclusion or exclusion of certain covariates may lead to different conclusions. Best practice requires investigators to understand the internal structure of their variables and to provide evidence that their variables assess their intended constructs.

scholarly journals Establishing diagnostic thresholds for Alzheimer's disease in adults with Down syndrome: the Cambridge Examination for Mental Disorders of Older People with Down's Syndrome and Others with Intellectual Disabilities (CAMDEX-DS)

BJPsych Open ◽  
2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Jessica A. Beresford-Webb ◽  
Elijah Mak ◽  
Monika Grigorova ◽  
Samuel J. Daffern ◽  
Anthony J. Holland ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down Syndrome ◽  
Mental Disorders ◽  
Older People ◽  
Intellectual Disabilities ◽  
Down’S Syndrome ◽  
Healthy Adults ◽  
Prodromal Alzheimer’S Disease ◽  
Alzheimer’S Disease Dementia

Background Diagnosis of prodromal Alzheimer's disease and Alzheimer's disease dementia in people with Down syndrome is a major challenge. The Cambridge Examination for Mental Disorders of Older People with Down's Syndrome and Others with Intellectual Disabilities (CAMDEX-DS) has been validated for diagnosing prodromal Alzheimer's disease and Alzheimer's disease dementia, but the diagnostic process lacks guidance. Aims To derive CAMDEX-DS informant interview threshold scores to enable accurate diagnosis of prodromal Alzheimer's disease and Alzheimer's disease dementia in adults with Down syndrome. Method Psychiatrists classified participants with Down syndrome into no dementia, prodromal Alzheimer's disease and Alzheimer's disease dementia groups. Receiver operating characteristic analyses assessed the diagnostic accuracy of CAMDEX-DS informant interview-derived scores. Spearman partial correlations investigated associations between CAMDEX-DS scores, regional Aβ binding (positron emission tomography) and regional cortical thickness (magnetic resonance imaging). Results Diagnostic performance of CAMDEX-DS total scores were high for Alzheimer's disease dementia (area under the curve (AUC), 0.998; 95% CI 0.953–0.999) and prodromal Alzheimer's disease (AUC = 0.954; 95% CI 0.887–0.982) when compared with healthy adults with Down syndrome. When compared with those with mental health conditions but no Alzheimer's disease, CAMDEX-DS Section B scores, denoting memory and orientation ability, accurately diagnosed Alzheimer's disease dementia (AUC = 0.958; 95% CI 0.892–0.984), but were unable to diagnose prodromal Alzheimer's disease. CAMDEX-DS total scores exhibited moderate correlations with cortical Aβ (r ~ 0.4 to 0.6, P ≤ 0.05) and thickness (r ~ −0.4 to −0.44, P ≤ 0.05) in specific regions. Conclusions CAMDEX-DS total score accurately diagnoses Alzheimer's disease dementia and prodromal Alzheimer's disease in healthy adults with Down syndrome.

scholarly journals Cognitive test battery for evaluating elderly Chinese Americans

2018 ◽  
Vol 31 (04) ◽  
pp. 505-511 ◽  
Author(s):  
Clara Li ◽  
Judith Neugroschl ◽  
Carolyn W. Zhu ◽  
Mari Umpierre ◽  
Jane Martin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Executive Function ◽  
Statistical Significance ◽  
Chinese Americans ◽  
Consensus Conference ◽  
Test Battery ◽  
Cognitive Domain ◽  
Cognitive Test ◽  
Elderly Chinese

ABSTRACTObjectives:This study aimed to determine the diagnostic utility of a Chinese test battery for evaluating cognitive loss in elderly Chinese Americans.Methods:Data from a pilot study at the Mount Sinai Alzheimer’s Disease Research Center was examined. All participants were > 65 years old, primarily Chinese speaking, with adequate sensorimotor capacity to complete cognitive tests. A research diagnosis of normal mild cognitive impairment (MCI) or Alzheimer’s disease (AD) was assigned to each participant in consensus conference. Composite scores were created to summarize test performance on overall cognition, memory, attention executive function, and language. Multivariable logistic regression models were used to assess the sensitivity of each cognitive domain for discriminating three diagnostic categories. Adjustment was made for demographic variables (i. e., age, gender, education, primary language, and years living in the USA).Results:The sample included 67 normal, 37 MCI, and 12 AD participants. Performance in overall cognition, memory, and attention executive function was significantly worse in AD than in MCI, and performance in MCI was worse than in normal controls. Language performance followed a similar pattern, but differences did not achieve statistical significance among the three diagnostic groups.Conclusions:This study highlights the need for cognitive assessment in elderly Chinese immigrants.

scholarly journals Haplogroups of Mitochondrial DNA Differentiate Patterns of Cognitive Change Over 7 Years

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 309-309
Author(s):  
Amber Watts ◽  
Elias Michaelis ◽  
Russell Swerdlow
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mitochondrial Dna ◽  
Executive Function ◽  
Cognitive Function ◽  
Cognitive Decline ◽  
Cognitive Performance ◽  
Verbal Memory ◽  
Cognitively Normal ◽  
Cognitive Domains

Abstract Mitochondrial DNA (mtDNA) may play an important role in Alzheimer’s disease (AD) and cognitive decline. A particular haplogroup of mtDNA (haplogroup J), has been observed more commonly in patients with AD than in cognitively normal controls. We used mtDNA haplogroups to predict change in cognitive performance over seven years. We hypothesized that haplogroup J would predict poorer cognitive function and steeper cognitive decline. We analyzed data from 140 cognitively normal older adults (age 65+) who participated in the University of Kansas Alzheimer’s Disease Center annual registry. We used factor analysis to create three composite scores (verbal memory, attention, executive function) from 11 individual cognitive tests. We performed latent growth curve modeling to describe trajectories of cognitive performance and change. We compared haplogroup H, the most common, to haplogroup J, the potential risk group. Results indicated haplogroup J carriers had significantly lower baseline performance (B=-.049, p< .01) and slower rates of improvement (B=-.046, p < .05) on tests of verbal memory compared to haplogroup H. For executive function, groups did not differ at baseline (B=.065, p>.10), but haplogroup J had slower rates of improvement (B=-.097, p < .01). There were no differences in attention across groups in performance (B=.135, p>.10) or change (B=-.01, p>.10). Our results reinforce the important role of mtDNA in changes to cognitive function with aging and imply that the effects of haplogroup J may vary across cognitive domains. Future research should investigate the mechanisms by which mtDNA might affect performance on specific cognitive domains across haplogroups.

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