title: Are frontal cognitive and atrophy patterns different in PSP and bvFTD? A comparative neuropsychological and VBM study.
abstract: Progressive supranuclear palsy (PSP) and frontotemporal lobar degeneration (FTD) are two clinicohistological entities that share a severe prefrontal syndrome. To what extent do the cognitive syndrome and the location of the underlying brain atrophy unify or segregate these entities? Here, we examined the clinical and radiological patterns of frontal involvement and the neural bases of the cognitive dysfunctions observed in the Richardson form of PSP and the behavioral variant of FTD (bvFTD). The cognitive profile and grey and white matter volume of PSP (n = 19) and bvFTD (n = 16) patients and control participants (n = 18) were compared using a standard battery of neuropsychological tests and voxel-based morphometry (VBM), respectively. Analyses of correlations between neuropsychological and morphometric data were additionally performed. The severity and qualitative pattern of cognitive dysfunction was globally similar between the two patient groups. Grey matter volume was decreased in widespread frontal areas and in the temporal uncus in bvFTD, while it was decreased in the frontal and temporal lobes as well as in the thalamus in PSP. We also found an unexpected involvement of the frontal rectal gyrus in PSP patients compared to controls. Correlation analyses yielded different results in the two groups, with no area showing significant correlations in PSP patients, while several frontal and some temporal areas did so in bvFTD patients. In spite of minor neuropsychological and morphological differences, this study shows that the patterns of cognitive dysfunction and atrophy are very similar in PSP and bvFTD. However, executive dysfunction in these diseases may stem from partially divergent cortical and subcortical neural circuits.
authors.affiliation: Department of Neurology, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France ; INSERM, UMR-975, CNRS, UMR-7225, Paris, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Lagarde
authors.forename: Romain
authors.initials: R
authors.lastname: Valabrègue
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Corvol
authors.forename: Fanny
authors.initials: F
authors.lastname: Pineau
authors.forename: Isabelle
authors.initials: I
authors.lastname: Le Ber
authors.forename: Marie
authors.initials: M
authors.lastname: Vidailhet
authors.forename: Bruno
authors.initials: B
authors.lastname: Dubois
authors.forename: Richard
authors.initials: R
authors.lastname: Levy
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003071:Cognition; D005260:Female; D005625:Frontal Lobe / Q000473:pathology* / Q000503:physiopathology; D057174:Frontotemporal Lobar Degeneration / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D013494:Supranuclear Palsy, Progressive / Q000473:pathology* / Q000503:physiopathology