title: Distinct white matter injury associated with medial temporal lobe atrophy in Alzheimer's versus semantic dementia.
abstract: This study aims at further understanding the distinct vulnerability of brain networks in Alzheimer's disease (AD) versus semantic dementia (SD) investigating the white matter injury associated with medial temporal lobe (MTL) atrophy in both conditions. Twenty-six AD patients, twenty-one SD patients, and thirty-nine controls underwent a high-resolution T1-MRI scan allowing to obtain maps of grey matter volume and white matter density. A statistical conjunction approach was used to identify MTL regions showing grey matter atrophy in both patient groups. The relationship between this common grey matter atrophy and white matter density maps was then assessed within each patient group. Patterns of grey matter atrophy were distinct in AD and SD but included a common region in the MTL, encompassing the hippocampus and amygdala. This common atrophy was associated with alterations in different white matter areas in AD versus SD, mainly including the cingulum and corpus callosum in AD, while restricted to the temporal lobe - essentially the uncinate and inferior longitudinal fasciculi - in SD. Complementary analyses revealed that these relationships remained significant when controlling for global atrophy or disease severity. Overall, this study provides the first evidence that atrophy of the same MTL region is related to damage in distinct white matter fibers in AD and SD. These different patterns emphasize the vulnerability of distinct brain networks related to the MTL in these two disorders, which might underlie the discrepancy in their symptoms. These results further suggest differences between AD and SD in the neuropathological processes occurring in the MTL. Hum Brain Mapp 38:1791-1800, 2017. © 2017 Wiley Periodicals, Inc.
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Bejanin
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Desgranges
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: La Joie
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Landeau
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Perrotin
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Mézenge
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|Service de Neurologie, CHU Pontchaillou, Rennes, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Belliard
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.|Service de Neurologie, CHU de Caen, Caen, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: de La Sayette
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.
authors.forename: Francis
authors.initials: F
authors.lastname: Eustache
authors.affiliation: U1077, Inserm, Caen, France.|UMR-S1077, Université de Caen - Normandie, Caen, France.|UMR-S1077, Ecole Pratique des Hautes Etudes, Caen, France.|U1077, CHU de Caen, Caen, France.
authors.forename: Gaël
authors.initials: G
authors.lastname: Chételat
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications* / Q000000981:diagnostic imaging; D000704:Analysis of Variance; D001284:Atrophy / Q000209:etiology; D005260:Female; D057180:Frontotemporal Dementia / Q000150:complications* / Q000000981:diagnostic imaging; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D056784:Leukoencephalopathies / Q000000981:diagnostic imaging / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D013223:Statistics as Topic; D013702:Temporal Lobe / Q000473:pathology*
keywords: Alzheimer's disease; hippocampus; medial temporal lobe; primary progressive aphasia; semantic dementia; white matter