title: Neural correlates of delayed episodic memory in patients with mild cognitive impairment--a FDG PET study.
abstract: Mild cognitive impairment (MCI) is characterized by cognitive deficits which do not yet reach the threshold of dementia but represent a putative preclinical state of Alzheimer's disease (AD). Little is known about the neural correlates of delayed episodic memory which is among the earliest signs of cognitive decline in patients at risk of developing AD. We performed resting state positron emission tomography (PET) with (18)Fluorodeoxyglucose (FDG) in patients with MCI, and hypothesized a correlation between delayed episodic memory performance and frontal glucose metabolism since the latter is relatively spared in the preclinical phase of the disease. 43 patients (age: 69.7+/-7.9 years; 24 male, 19 female) with MCI were investigated by FDG PET. Significant positive correlations with delayed episodic memory performance were calculated by statistical parametric mapping. To our knowledge the present study is the first to demonstrate by FDG PET the neural correlates of delayed episodic memory in patients with MCI. Our study revealed a pattern of cerebral glucose metabolism including bifrontal regions which may contribute to the delayed episodic memory performance of patients with MCI. Since not all patients with MCI will further deteriorate, AD specific mechanism may not be concluded from the present study but warrant longitudinal investigations.
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Leipzig, Semmelweisstr. 10, 04103 Leipzig, Germany. Peter.Schoenknecht@medizin.uni-leipzig.de
authors.forename: Oskar Dieter Peter
authors.initials: OD
authors.lastname: Schönknecht
authors.forename: Aoife
authors.initials: A
authors.lastname: Hunt
authors.forename: Pablo
authors.initials: P
authors.lastname: Toro
authors.forename: Marcus
authors.initials: M
authors.lastname: Henze
authors.forename: Uwe
authors.initials: U
authors.lastname: Haberkorn
authors.forename: Johannes
authors.initials: J
authors.lastname: Schröder
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000378:metabolism / Q000503:physiopathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005625:Frontal Lobe / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008297:Male; D008568:Memory; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014705:Verbal Behavior
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose