title: Perseverative errors on the Wisconsin Card Sorting Test and brain perfusion imaging in mild Alzheimer's disease.
abstract: BACKGROUND
  The Wisconsin Card Sorting Test (WCST) has long been used to investigate deficits in executive function in humans. The majority of studies investigating deficient WCST performance focused on the number of categories achieved (CA) and the number of perseverative errors of the Nelson type (PEN). However, there is insufficient evidence that these two measures reflect the same neural deficits.
  
  
  METHODS
  Twenty AD patients with high PEN scores, and 20 age- and sex-matched AD patients with low PEN scores were selected. All 40 subjects underwent brain SPECT, and the SPECT images were analyzed by Statistical Parametric Mapping.
  
  
  RESULTS
  No significant differences were found between high and low PEN score groups with respect to years of education, Addenbrooke's Cognitive Examination scores, and Mini-Mental State Examination scores. However, higher z scores for hypoperfusion in the bilateral rectal and orbital gyri were observed in the high PEN score group compared with the low PEN score group.
  
  
  CONCLUSIONS
  Our results suggest that functional activity of the bilateral rectal and orbital gyri is closely related to PEN scores on a modified WCST (mWCST). The PEN score on a mWCST might be a promising index of dysfunction of the orbitofrontal area among patients with mild AD.
authors.affiliation: Department of Neuropsychiatry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. terada@cc.okayama-u.ac.jp
authors.forename: Seishi
authors.initials: S
authors.lastname: Terada
authors.forename: Shuhei
authors.initials: S
authors.lastname: Sato
authors.forename: Hajime
authors.initials: H
authors.lastname: Honda
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kishimoto
authors.forename: Naoya
authors.initials: N
authors.lastname: Takeda
authors.forename: Etsuko
authors.initials: E
authors.lastname: Oshima
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokota
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Uchitomi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000523:psychology*; D001921:Brain / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000592:standards*; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon