title: Frontal and posterior cingulate metabolic impairment in the behavioral variant of frontotemporal dementia with impaired autonoetic consciousness.
abstract: Although memory dysfunction is not a prominent feature of the behavioral variant of frontotemporal dementia (bv-FTD), there is evidence of specific deficits of episodic memory in these patients. They also have problems monitoring their memory performance. The objective of the present study was to explore the ability to consciously retrieve own encoding of the context of events (autonoetic consciousness) and the ability to monitor memory performance using feeling-of-knowing (FOK) in bv-FTD. Analyses of the patients' cerebral metabolism (FDG-PET) allowed an examination of whether impaired episodic memory in bv-FTD is associated with the frontal dysfunction characteristic of the pathology or a dysfunction of memory-specific regions pertaining to Papez's circuit. Data were obtained from eight bv-FTD patients and 26 healthy controls. Autonoetic consciousness was evaluated by Remember responses during the recognition memory phase of the FOK experiment. As a group, bv-FTD patients demonstrated a decline in autonoetic consciousness and FOK accuracy at the chance level. While memory monitoring was impaired in most (seven) patients, four bv-FTD participants had individual impairment of autonoetic consciousness. They specifically showed reduced metabolism in the anterior medial prefrontal cortex, the left dorsolateral prefrontal cortex (near the superior frontal sulcus), parietal regions, and the posterior cingulate cortex. These findings were tentatively interpreted by considering the role of the metabolically impaired brain regions in self-referential processes, suggesting that the bv-FTD patients' problem consciously retrieving episodic memories may stem at least partly from deficient access to and maintenance/use of information about the self. Frontal and posterior cingulate metabolic impairment in the behavioral variant of frontotemporal dementia with impaired autonoetic consciousness
authors.affiliation: Cyclotron Research Centre, University of Liège, Belgium. Christine.Bastin@ulg.ac.be
authors.forename: Christine
authors.initials: C
authors.lastname: Bastin
authors.forename: Dorothée
authors.initials: D
authors.lastname: Feyers
authors.forename: Céline
authors.initials: C
authors.lastname: Souchay
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Guillaume
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Pepin
authors.forename: Christian
authors.initials: C
authors.lastname: Lemaire
authors.forename: Christian
authors.initials: C
authors.lastname: Degueldre
authors.forename: Fabienne
authors.initials: F
authors.lastname: Collette
authors.forename: Eric
authors.initials: E
authors.lastname: Salmon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology; D001364:Awareness / Q000502:physiology*; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology; D003243:Consciousness / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D057180:Frontotemporal Dementia / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology / Q000523:psychology; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011877:Radionuclide Imaging