title: Brain correlates of performance in a free/cued recall task with semantic encoding in Alzheimer disease.
abstract: The goal of this study was to explore in patients with Alzheimer's disease (AD) the brain correlates of free and cued recall performance using an adaptation of the procedure developed by Grober and Buschke (1987). This procedure, which ensures semantic processing and coordinates encoding and retrieval, has been shown to be very sensitive to an early diagnosis of AD. Statistical parametric mapping (SPM 99) was used to establish clinicometabolic correlations between performance at free and cued verbal recall and resting brain metabolism in 31 patients with AD. Results showed that patient's score on free recall correlated with metabolic activity in right frontal regions (BA 10 and BA 45), suggesting that performance reflected a strategic retrieval attempt. Poor retrieval performance was tentatively attributed to a loss of functional correlation between frontal and medial temporal regions in patients with AD compared with elderly controls. Performance on cued recall was correlated to residual metabolic activity in bilateral parahippocampal regions (BA 36), suggesting that performance reflected retrieval of semantic associations, without recollection in AD. In conclusion, this study demonstrates that the diagnostic sensitivity for Alzheimer's disease of the cued recall performance in the Grober and Buschke procedure (1987) depends on the activity of parahippocampal regions, one of the earliest targets of the disease. Moreover, the results suggest that the poor performance of patients with AD during free and cued recall is related to a decreased connectivity between parahippocampal regions and frontal areas.
authors.affiliation: Cyclotron Research Center, University of Liège, Belgium. Francoise.Lekeu@ulg.ac.be
authors.forename: Françoise
authors.initials: F
authors.lastname: Lekeu
authors.forename: Martial
authors.initials: M
authors.lastname: Van der Linden
authors.forename: Christian
authors.initials: C
authors.lastname: Chicherio
authors.forename: Fabienne
authors.initials: F
authors.lastname: Collette
authors.forename: Christian
authors.initials: C
authors.lastname: Degueldre
authors.forename: Georges
authors.initials: G
authors.lastname: Franck
authors.forename: Gustave
authors.initials: G
authors.lastname: Moonen
authors.forename: Eric
authors.initials: E
authors.lastname: Salmon
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology*; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001931:Brain Mapping; D003463:Cues; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007802:Language; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D012660:Semantics; D014055:Tomography, Emission-Computed
chemical_list: D005947:Glucose