White matter tract integrity metrics reflect the vulnerability of late-myelinating tracts in Alzheimer's disease
| Autor: | Els Fieremans, Ali Tabesh, Joseph A. Helpern, Jens H. Jensen, Maria F. Falangola, Steven H. Ferris, Andreana Benitez |
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| Rok vydání: | 2014 |
| Předmět: |
Male
Internal capsule DKI diffusional kurtosis imaging Daxon intrinsic axonal diffusivity aMCI amnestic mild cognitive impairment Neuropsychological Tests De ⊥ radial extra-axonal diffusivity lcsh:RC346-429 Myelin 0302 clinical medicine SLF superior longitudinal fasciculus Image Processing Computer-Assisted Verbal fluency test FA fractional anisotropy ILF inferior longitudinal fasciculus Cognitive decline NC normal control Myelin Sheath Aged 80 and over 0303 health sciences White matter Cognition Alzheimer's disease Magnetic Resonance Imaging Semantics Diffusion Tensor Imaging medicine.anatomical_structure Neurology lcsh:R858-859.7 Female Diffusional kurtosis imaging AD Alzheimer's disease Psychology Cognitive Neuroscience CP cerebral peduncle lcsh:Computer applications to medicine. Medical informatics Verbal fluency AWF axonal water fraction Article Diffusion MRI 03 medical and health sciences Alzheimer Disease medicine Humans Cognitive Dysfunction Radiology Nuclear Medicine and imaging WM white matter lcsh:Neurology. Diseases of the nervous system Aged 030304 developmental biology De ∥ axial extra-axonal diffusivity Psychiatric Status Rating Scales Analysis of Variance WMTI white matter tract integrity medicine.disease PLIC posterior limb of the internal capsule DTI diffusion tensor imaging Neurology (clinical) Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | NeuroImage : Clinical NeuroImage: Clinical, Vol 4, Iss C, Pp 64-71 (2014) |
| ISSN: | 2213-1582 |
| Popis: | Post-mortem and imaging studies have observed that white matter (WM) degenerates in a pattern inverse to myelin development, suggesting preferential regional vulnerabilities influencing cognitive decline in AD. This study applied novel WM tract integrity (WMTI) metrics derived from diffusional kurtosis imaging (DKI) to examine WM tissue properties in AD within this framework. Using data from amnestic mild cognitive impairment (aMCI, n = 12), AD (n = 14), and normal control (NC; n = 15) subjects, mixed models revealed interaction effects: specific WMTI metrics of axonal density and myelin integrity (i.e. axonal water fraction, radial extra-axonal diffusivity) in late-myelinating tracts (i.e. superior and inferior longitudinal fasciculi) changed in the course of disease, but were stable in the initial stages for early-myelinating tracts (i.e. posterior limb of the internal capsule, cerebral peduncles). WMTI metrics in late-myelinating tracts correlated with semantic verbal fluency, a cognitive function known to decline in AD. These findings corroborate the preferential vulnerability of late-myelinating tracts, and illustrate an application of WMTI metrics to characterizing the regional course of WM changes in AD. Highlights • We investigated the vulnerability of late-myelinating tracts in AD using WMTI metrics. • WMTI metrics are derived from the biophysical modeling of the DKI signal. • These metrics indicate pathological features like axonal density and myelin integrity. • WMTI metrics were largely stable in early-myelinating tracts through the course of AD. • Axonal density loss & myelin breakdown were observed in late-myelinating tracts. |
| Databáze: | OpenAIRE |
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