title: Neuropsychological performance in early and late onset Alzheimer's disease: comparisons in a memory clinic population.
abstract: OBJECTIVE
  To compare the neuropsychological performance associated with early and late onset Alzheimer's disease (AD), in order to identify differences and compare these with previous reports.
  
  
  METHODS
  Patients attending a memory clinic were given a detailed multi-disciplinary diagnostic assessment, including a battery of neuropsychological tests. From those meeting ICD-10 criteria for Alzheimer's disease (AD), an early-onset (EO) group (n = 40) and a late-onset (LO) group (n = 90) were identified, and their performances compared. Patients with mixed dementia and co-morbid depression were excluded.
  
  
  RESULTS
  After adjustment, the EO and LO groups performed at a comparable level on the majority of the neuropsychological tests. The LO group performed better on the WAIS digit span test, AMIPB Complex Design and the written picture description, and the EO group performed better on the WAIS similarities test and the Boston naming test.
  
  
  CONCLUSIONS
  These findings suggest that, after adjusting for overall dementia severity and pre-morbid IQ, there is greater fronto-parietal/right hemisphere involvement in early-onset AD, and greater temporal/left hemisphere involvement in late-onset AD. This may be due to different genetic risk profiles for AD at different ages.
authors.affiliation: Department of Health Sciences, University of Leicester, Leicester, UK. srisuri@yahoo.com
authors.forename: Srinivas
authors.initials: S
authors.lastname: Suribhatla
authors.forename: Sarah
authors.initials: S
authors.lastname: Baillon
authors.forename: Michael
authors.initials: M
authors.lastname: Dennis
authors.forename: Mangesh
authors.initials: M
authors.lastname: Marudkar
authors.forename: Saquib
authors.initials: S
authors.lastname: Muhammad
authors.forename: Dena
authors.initials: D
authors.lastname: Munro
authors.forename: Christine
authors.initials: C
authors.lastname: Spreadbury
authors.forename: James
authors.initials: J
authors.lastname: Lindesay
mesh_terms: D017668:Age of Onset; D000368:Aged; D000544:Alzheimer Disease / Q000523:psychology*; D003071:Cognition; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D007807:Language Tests; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D013060:Speech