(DOWNLOAD) "Quantifying Early Cognitive Decline in Healthy Controls As Related to the Risk Factors of Apolipoprotein E (APOE) e4 and the Cerebrospinal Fluid (CSF) Biomarkers of b-Amyloid 1 -42 and Tau in Alzheimer's Disease" by Karen T. Putnam ~ eBook PDF Kindle ePub Free
eBook details
- Title: Quantifying Early Cognitive Decline in Healthy Controls As Related to the Risk Factors of Apolipoprotein E (APOE) e4 and the Cerebrospinal Fluid (CSF) Biomarkers of b-Amyloid 1 -42 and Tau in Alzheimer's Disease
- Author : Karen T. Putnam
- Release Date : January 18, 2013
- Genre: Medical,Books,Professional & Technical,
- Pages : * pages
- Size : 3303 KB
Description
The elderly account for an increasingly significant proportion of the overall population in the United States. Incidence rates of Alzheimer’s disease double with each five years of age reaching an estimated prevalence of 45% by age 85 years. The objectives of this study were to compare neuropsychological composites scores in asymptomatic controls stratified by known biologic risk factors for AD to explore early signals of cognitive decline. Methods:Participants were enrolled in the National Institute of Mental Health (NIMH) longitudinal protocol of Biomarkers in Older Controls “At Risk” for Dementia (BIOCARD). Neuropsychological composite index scores were examined for early signals of decline in a baseline cross-sectional sample of 199 healthy control subjects stratified by the known AD risk factors of APOE ε4 and advanced aging. Additionally, neuropsychological indices were correlated with the CSF proteins of β-amyloid 1-42 and tau in 57% of these subjects. Results: Cognitive z scores indices of word memory learning and story memory learning were influenced by the presence of the APOE ε4 allele. These memory indices, along with visuospatial abilities were also influenced by advanced aging. The cognitive index domains of semantic language and visuospatial attention did not appear sensitive to early signals of decline in this sample. CSF tau levels were highly correlated with age. Composite indices of word memory learning and visuospatial abilities were also associated with CSF tau levels. CSF β-amyloid 1-42 was correlated with age, but not associated with any of the cognitive indices. Conclusions: Memory is typically the first cognitive domain to show signs of impairment in AD. The memory composite measures reported here were sensitive to both the presence of the APOE ε4 allele and one of the known AD CSF biomarkers in healthy, cognitively asymptomatic controls. Careful longitudinal follow-up will be necessary to assess the sensitivity and specificity of these measures as clinical tools in quantifying the early stages of MCI.