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IC‐P‐054: Grey matter differences in genetic frontotemporal dementia: Results from the genfi study
Author(s) -
Cash David M.,
Dick Katrina M.,
Fellows Alexander,
Espak Miklos,
Swieten John C.,
Galimberti Daniela,
Borroni Barbara,
Masellis Mario,
Tagliavini Fabrizio,
Graff Caroline,
Rowe James,
Frisoni Giovanni Battista,
Laforce Robert,
Finger Elizabeth,
Sorbi Sandro,
Mendonça Alexandre,
Rossor Martin N.,
Ourselin Sebastien,
Rohrer Jonathan D.
Publication year - 2015
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.2015.06.075
Subject(s) - frontotemporal dementia , c9orf72 , atrophy , grey matter , semantic dementia , psychology , magnetic resonance imaging , pathology , dementia , audiology , medicine , neuroscience , white matter , radiology , disease
amnesia, episodic memory is relatively spared in SD. Conversely, semantic memory is preserved in the earliest stage of AD while semantic deficits predominate in the clinical picture of SD. Based on evidence in healthy subjects, it has recently been suggested that these two disorders might be associated with damages in different brain networks involving the MTL. The present study aims at assessing, for the first time in patients, whether the common MTL atrophy is associated with distinct structural connectivity in AD and SD. Methods:A total of 27 patients with AD, 21 patients with SD and 39 healthy controls matched for age, sex and years of education underwent a high-resolution T1-MRI scan. The area of common atrophy (i.e. reduced volume compared to healthy controls) in both patient groups (FWE p<.05, k1⁄4200) was identified using a statistical conjunction approach. Then, the mean volume of the MTL included in the conjunction was correlated with white matter density within each patient group (p1⁄4.005 uncorrected, k1⁄4200). Results: While comparisons with controls highlighted different patterns of atrophy in AD and SD, the statistical conjunction revealed a common atrophy in the MTL, encompassing the hippocampus and amygdala bilaterally. The correlations with white matter density showed two distinct patterns of structural connectivity associated with the common MTL gray matter loss in each group. In AD, the correlations included primarily the caudal and rostral portion of both the cingulum and the corpus callosum. Regarding SD, the correlations were restricted within the temporal lobe and comprised mainly the uncinate, the inferior fronto-occipital and the inferior longitudinal fasciculi. Conclusions:Our results highlighted that the commonMTL atrophy in AD and SD is related to injury in distinct white matter fibers, thought to be part of different brain networks. Our findings thus corroborate the hypothesis of distinct vulnerability of brain networks in AD and SD despite common MTL atrophy, which is proposed to account for the discrepancy in the symptoms of these two neurodegenerative disorders.