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P1‐351: Transition of brain structural changes in relation to cognitive decline in Alzheimer's disease: evidence from the Alzheimer's Disease Neuroimaging Initiative
Author(s) -
Song Xiaowei,
Mitnitski Arnold,
Zhang Ningnannan,
Rockwood Kenneth
Publication year - 2011
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2011.05.631
Subject(s) - alzheimer's disease neuroimaging initiative , atrophy , neuroimaging , cognitive decline , psychology , cognition , disease , magnetic resonance imaging , cardiology , medicine , dementia , neuroscience , audiology , radiology
Background: Brain structural changes (atrophy, vascular, lesions) are related to cognitive decline in aging and inAlzheimer’s disease (AD).A brain atrophy and lesion index (BALI), based on magnetic resonance imaging (MRI) has been validated to summarize various common structural deficits in the aging brain. Here we apply the BALI rating to investigate transitions of brain structural deficits in AD, mild cognitive impairment (MCI), and healthy control subjects (HC) using longitudinal MRI data. We also investigate transitions in overall brain structural deficits (represented by the total BALI score) in relation to cognition and vascular risk factors.Methods: Imaging data from 125 subjects (AD1⁄4 26, MCI1⁄4 53, CN1⁄4 46; aged 55-91 years at baseline) were obtained from the Alzheimer’s Disease Neuro imaging Initiative (ADNI). All subjects had a 3 Tesla, 3D T1-weighted scans at baseline and at 24 months. BALI-defined stages of brain structural deficits were evaluated using a multi-state stochastic model, which was also applied to the MMSE and ADAS-Cog scores.Results: Transitions of brain structural deficits and cognitive performance within two years included decline, stability, and improvement, although most people showed worsened/stabled states. Adjusted for multiple covariates including age, sex, and education, transitions inbrain structural deficitswere significantly affectedby the baseline state of braindeficits (p < 0.01), and by age, diagnosis, and the presence of any vascular risk factor. For the MCI subgroup, the chance of progression in structural deficits was more than two times greater in those who converted to AD compared to non-converters.Notably, noMCIpatientswhoseBALI score improved showed clinical worsening.Higher (worse) BALI scores strongly affected cognitive transitions (p< 0.01).Conclusions: Transitions in brain structural deficits are related to clinical changes in cognition and the chance of conversion from MCI to AD. Brain structural changes can be affected bymodifiable elements such as exposures to vascular risk factors. Brain structural transitions are well captured by a stochastic model, which also allows for the possibility of improvement. These data suggest that brain aging is a dynamic process; the possibility for improvement is not only cognitive function but also brain structure.