Selective Disruption of the Cerebral Neocortex in Alzheimer's Disease
Date
2010-9-23
Authors
Desikan, Rahul S.
Sabuncu, Mert R.
Schmansky, Nicholas J.
Reuter, Martin
Cabral, Howard J.
Hess, Christopher P.
Weiner, Michael W.
Biffi, Alessandro
Anderson, Christopher D.
Rosand, Jonathan
Version
OA Version
Citation
Desikan, Rahul S., Mert R. Sabuncu, Nicholas J. Schmansky, Martin Reuter, Howard J. Cabral, Christopher P. Hess, Michael W. Weiner, Alessandro Biffi, Christopher D. Anderson, Jonathan Rosand, David H. Salat, Thomas L. Kemper, Anders M. Dale, Reisa A. Sperling, Bruce Fischl. "Selective Disruption of the Cerebral Neocortex in Alzheimer's Disease" PLoS ONE 5(9): e12853. (2010)
Abstract
BACKGROUND. Alzheimer's disease (AD) and its transitional state mild cognitive impairment (MCI) are characterized by amyloid plaque and tau neurofibrillary tangle (NFT) deposition within the cerebral neocortex and neuronal loss within the hippocampal formation. However, the precise relationship between pathologic changes in neocortical regions and hippocampal atrophy is largely unknown. METHODOLOGY/PRINCIPAL FINDINGS. In this study, combining structural MRI scans and automated image analysis tools with reduced cerebrospinal fluid (CSF) Aß levels, a surrogate for intra-cranial amyloid plaques and elevated CSF phosphorylated tau (p-tau) levels, a surrogate for neocortical NFTs, we examined the relationship between the presence of Alzheimer's pathology, gray matter thickness of select neocortical regions, and hippocampal volume in cognitively normal older participants and individuals with MCI and AD (n=724). Amongst all 3 groups, only select heteromodal cortical regions significantly correlated with hippocampal volume. Amongst MCI and AD individuals, gray matter thickness of the entorhinal cortex and inferior temporal gyrus significantly predicted longitudinal hippocampal volume loss in both amyloid positive and p-tau positive individuals. Amongst cognitively normal older adults, thinning only within the medial portion of the orbital frontal cortex significantly differentiated amyloid positive from amyloid negative individuals whereas thinning only within the entorhinal cortex significantly discriminated p-tau positive from p-tau negative individuals. CONCLUSIONS/SIGNIFICANCE. Cortical Aß and tau pathology affects gray matter thinning within select neocortical regions and potentially contributes to downstream hippocampal degeneration. Neocortical Alzheimer's pathology is evident even amongst older asymptomatic individuals suggesting the existence of a preclinical phase of dementia.
Description
License
Desikan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.