Mapping correlations between ventricular expansion and CSF amyloid and tau biomarkers in 240 subjects with Alzheimer's disease, mild cognitive impairment and elderly controls

Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-7332, USA.
NeuroImage (Impact Factor: 6.36). 03/2009; 46(2):394-410. DOI: 10.1016/j.neuroimage.2009.02.015
Source: PubMed


We aimed to improve on the single-atlas ventricular segmentation method of (Carmichael, O.T., Thompson, P.M., Dutton, R.A., Lu, A., Lee, S.E., Lee, J.Y., Kuller, L.H., Lopez, O.L., Aizenstein, H.J., Meltzer, C.C., Liu, Y., Toga, A.W., Becker, J.T., 2006. Mapping ventricular changes related to dementia and mild cognitive impairment in a large community-based cohort. IEEE ISBI. 315-318) by using multi-atlas segmentation, which has been shown to lead to more accurate segmentations (Chou, Y., Leporé, N., de Zubicaray, G., Carmichael, O., Becker, J., Toga, A., Thompson, P., 2008. Automated ventricular mapping with multi-atlas fluid image alignment reveals genetic effects in Alzheimer's disease, NeuroImage 40(2): 615-630); with this method, we calculated minimal numbers of subjects needed to detect correlations between clinical scores and ventricular maps. We also assessed correlations between emerging CSF biomarkers of Alzheimer's disease pathology and localizable deficits in the brain, in 80 AD, 80 mild cognitive impairment (MCI), and 80 healthy controls from the Alzheimer's Disease Neuroimaging Initiative. Six expertly segmented images and their embedded parametric mesh surfaces were fluidly registered to each brain; segmentations were averaged within subjects to reduce errors. Surface-based statistical maps revealed powerful correlations between surface morphology and 4 variables: (1) diagnosis, (2) depression severity, (3) cognitive function at baseline, and (4) future cognitive decline over the following year. Cognitive function was assessed using the mini-mental state exam (MMSE), global and sum-of-boxes clinical dementia rating (CDR) scores, at baseline and 1-year follow-up. Lower CSF Abeta(1-42) protein levels, a biomarker of AD pathology assessed in 138 of the 240 subjects, were correlated with lateral ventricular expansion. Using false discovery rate (FDR) methods, 40 and 120 subjects, respectively, were needed to discriminate AD and MCI from normal groups. 120 subjects were required to detect correlations between ventricular enlargement and MMSE, global CDR, sum-of-boxes CDR and clinical depression scores. Ventricular expansion maps correlate with pathological and cognitive measures in AD, and may be useful in future imaging-based clinical trials.

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Available from: Leslie M Shaw
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    • "Prior methods for ventricular segmentation have used semiautomated , automated (Chou et al., 2008), and single-atlas or multi-atlas methods (Chou et al., 2009). Here we segmented the ventricles with our modified multi-atlas approach (Gutman et al., 2013; Madsen et al., 2013). "
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    ABSTRACT: A recent genome-wide association meta-analysis showed a suggestive association between alcohol intake in humans and a common single nucleotide polymorphism in the ras-specific guanine nucleotide releasing factor 2 gene. Here, we tested whether this variant - associated with lower alcohol consumption - showed associations with brain structure and longitudinal ventricular expansion over time, across two independent elderly cohorts, totaling 1,032 subjects. We first examined a large sample of 738 elderly participants with neuroimaging and genetic data from the Alzheimer's Disease Neuroimaging Initiative (ADNI1). Then, we assessed the generalizability of the findings by testing this polymorphism in a replication sample of 294 elderly subjects from a continuation of the first ADNI project (ADNI2) to minimize the risk of reporting false positive results. The minor allele - previously linked with lower alcohol intake - was associated with larger volumes in various cortical regions, notably the medial prefrontal cortex and cingulate gyrus in both cohorts. Intriguingly, the same allele also predicted faster ventricular expansion rates in the ADNI1 cohort at 1- and 2-year follow up. Despite a lack of alcohol consumption data in this study cohort, these findings, combined with earlier functional imaging investigations of the same gene, suggest the existence of reciprocal interactions between genes, brain, and drinking behavior.
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    • "However, more studies are needed before it is possible to make general recommendation on the use of CSF biomarkers in the clinic to identify mixed cases of INPH-AD [82]. The distinctive alterations in ventricular size [83,84] and CSF dynamics associated with INPH have been shown to alter the concentration gradients of monoamine metabolites in CSF of hydrocephalus patients [85,86] and could alter the concentrations of other CSF biomarkers in unpredictable ways. "
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    • "A crucial question regards whether these atrophic processes in the brains of healthy elderly individuals are related to the cerebrospinal fluid (CSF) biomarkers b-amyloid 1-42 (Ab1-42) and tau proteins, potentially reflecting age-related neurodegenerative mechanisms. Depositions of extracellular plaques (Ab1-42) and intracellular neurofibrillary tangles (tau) are believed to play causative roles in neurodegeneration in Alzheimer's disease (AD; Goedert and Spillantini 2006; Spires-Jones et al. 2009a), and CSF levels of these biomarkers correlate with rates of atrophy and ventricular expansion (Hampel et al. 2005; de Leon et al. 2006; Chou et al. 2009; Schuff et al. 2009). However, it is unclear whether and to what extent these CSF biomarkers are related to neurodegenerative effects also in healthy elderly individuals. "
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