title: The superficial white matter in Alzheimer's disease.
abstract: White matter abnormalities have been shown in the large deep fibers of Alzheimer's disease patients. However, the late myelinating superficial white matter comprised of intracortical myelin and short-range association fibers has not received much attention. To investigate this area, we extracted a surface corresponding to the superficial white matter beneath the cortex and then applied a cortical pattern-matching approach which allowed us to register and subsequently sample diffusivity along thousands of points at the interface between the gray matter and white matter in 44 patients with Alzheimer's disease (Age: 71.02 ± 5.84, 16M/28F) and 47 healthy controls (Age 69.23 ± 4.45, 19M/28F). In patients we found an overall increase in the axial and radial diffusivity across most of the superficial white matter (P < 0.001) with increases in diffusivity of more than 20% in the bilateral parahippocampal regions and the temporal and frontal lobes. Furthermore, diffusivity correlated with the cognitive deficits measured by the Mini-Mental State Examination scores (P < 0.001). The superficial white matter has a unique microstructure and is critical for the integration of multimodal information during brain maturation and aging. Here we show that there are major abnormalities in patients and the deterioration of these fibers relates to clinical symptoms in Alzheimer's disease.
authors.affiliation: Morphology and Morphometry for NeuroImaging Lab, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia Foundation, Rome, Italy.|Neuroscience Dept. University of Rome, "Tor Vergata", Italy.
authors.forename: Owen R
authors.initials: OR
authors.lastname: Phillips
authors.affiliation: Ahmanson Lovelace Brain Mapping Center, Neurology Dept. UCLA, California, USA.
authors.forename: Shantanu H
authors.initials: SH
authors.lastname: Joshi
authors.affiliation: Museo Storico della Fisica e Centro di Studi e Ricerche "Enrico Fermi", Rome, Italy.|Neuropsychiatry Laboratory, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia Foundation, Rome, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Piras
authors.affiliation: Neuropsychiatry Laboratory, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia Foundation, Rome, Italy.
authors.forename: Maria Donata
authors.initials: MD
authors.lastname: Orfei
authors.affiliation: Neuropsychiatry Laboratory, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia Foundation, Rome, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Iorio
authors.affiliation: Ahmanson Lovelace Brain Mapping Center, Neurology Dept. UCLA, California, USA.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Narr
authors.affiliation: Ahmanson Lovelace Brain Mapping Center, Neurology Dept. UCLA, California, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Shattuck
authors.affiliation: Neuroscience Dept. University of Rome, "Tor Vergata", Italy.|Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia Foundation, Rome, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Caltagirone
authors.affiliation: Neuropsychiatry Laboratory, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia Foundation, Rome, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Spalletta
authors.affiliation: Morphology and Morphometry for NeuroImaging Lab, Clinical and Behavioural Neurology Dept. IRCCS Santa Lucia Foundation, Rome, Italy.|Human Studies Dept. LUMSA University, Rome, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Di Paola
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000378:metabolism; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D066127:White Matter / Q000000981:diagnostic imaging* / Q000378:metabolism
keywords: DTI; U-fibers; diffusion; interstitial neurons; intracortical myelin; neurodegeneration; oligodendrocytes; short-range association fibers; white matter