title: Neuropsychological and neuroimaging markers in early versus late-onset Alzheimer's disease.
abstract: BACKGROUND
  Early-onset Alzheimer's disease (EOAD) has been overshadowed by the more common late-onset AD (LOAD). Yet, the literature indicates EOAD may have less hippocampal-memory presentations and more focal neocortical localization early in the disease.
  
  
  OBJECTIVE
  To evaluate these proposed differences between these 2 forms of AD and to explore what they inform about differences in AD pathophysiology.
  
  
  METHODS
  In all, 21 patients with EOAD and 24 patients with LOAD matched for disease progression and severity were compared on neurocognitive measures and resting state fluorodeoxy-glucose positron-emission tomography (FDG-PET).
  
  
  RESULTS
  Patients with EOAD had worse executive functions with greater hypometabolism in the parietal regions; whereas patients with LOAD had worse confrontation naming and verbal recognition memory with greater hypometabolism in inferior frontotemporal regions.
  
  
  CONCLUSIONS
  In addition to highlighting significant differences between EOAD and LOAD, these results reveal dissociation between executive deficits in AD and frontal hypometabolism, suggesting early disturbances of the parietal-frontal network in EOAD.
authors.affiliation: VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA. natalie.kaiser@va.gov
authors.forename: Natalie C
authors.initials: NC
authors.lastname: Kaiser
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Melrose
authors.forename: Collin
authors.initials: C
authors.lastname: Liu
authors.forename: David L
authors.initials: DL
authors.lastname: Sultzer
authors.forename: Elvira
authors.initials: E
authors.lastname: Jimenez
authors.forename: Michael
authors.initials: M
authors.lastname: Su
authors.forename: Lorena
authors.initials: L
authors.lastname: Monserratt
authors.forename: Mario F
authors.initials: MF
authors.lastname: Mendez
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D059907:Functional Neuroimaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18