title: Visuospatial planning and problem solving in Alzheimer's disease patients: a study with the Tower of London Test.
abstract: BACKGROUND
  Executive dysfunction in Alzheimer's disease (AD) has been recently recognized as an early and prominent clinical sign. The Tower of London (ToL), a task specifically devised to test executive functions of visuospatial planning and problem solving, has frequently been used in neuropsychological experiments, but rarely in the clinical ground.
  
  
  METHODS
  One hundred and sixty-one AD patients and 212 nondemented healthy controls were administered a simplified ToL version.
  
  
  RESULTS
  AD patients were significantly impaired (p < 0.0001) in all ToL scores and in the total execution time. The 'accuracy' score of ToL at a cut off of <or=29/36 yielded a sensitivity of 71.2% and a specificity of 76.4% (AUC 0.79) for the diagnosis of AD versus controls.
  
  
  CONCLUSIONS
  Visuospatial planning and problem solving are significantly impaired in early dementia of the Alzheimer's type. A successful sensitivity/specificity ratio, the independence of education and the simplicity of this version of ToL make it a useful executive functioning screening test for early AD.
authors.affiliation: Neurology Department, IRCCS Multimedica, Castellanza, Italy. massimo.franceschi@multimedica.it
authors.forename: Massimo
authors.initials: M
authors.lastname: Franceschi
authors.forename: Paolo
authors.initials: P
authors.lastname: Caffarra
authors.forename: Luc
authors.initials: L
authors.lastname: De Vreese
authors.forename: Oriana
authors.initials: O
authors.lastname: Pelati
authors.forename: Samantha
authors.initials: S
authors.lastname: Pradelli
authors.forename: Rita
authors.initials: R
authors.lastname: Savarè
authors.forename: Renata
authors.initials: R
authors.lastname: Cerutti
authors.forename: Enzo
authors.initials: E
authors.lastname: Grossi
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000453:epidemiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D015995:Prevalence; D012720:Severity of Illness Index; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*