title: Perseverative error in schizophrenia: correlation with cortical blood flow by SPECT.
abstract: BACKGROUND
  Perseverative error (PE) is a core symptom of schizophrenia which has been proposed as a phenotypic marker of the illness. Moreover, hypofrontality observed in functional neuroimaging studies while executing a cognitive task has also been suggested as a characteristic sign of schizophrenia. We propose combining symptom and sign to demonstrate the existence of a regional cortical blood flow (RCBF) pattern associated to PE that might constitute a biological marker of schizophrenia.
  
  
  METHODS
  We used Single Photon Emission Computerized Tomography (SPECT), to study the RCBF associated to PE and to correct response (CR), during the execution of the Wisconsin Card Sorting Test (WCST), of 18 patients with schizophrenia and 13 controls. We focused on five well-defined bilateral brain regions, using the RCBF of the same regions at rest as a baseline.
  
  
  RESULTS
  Patients made more PE than controls in the WCST. Among patients, we observed a correlation between PEs and right occipital RCBF. Among controls, we found a negative correlation between PEs and left temporal cortex RCBF and a positive correlation between CRs and left frontobasal and overall left frontal cortexes RCBF.
  
  
  CONCLUSIONS
  The severity of PE is associated to higher right parietal-occipital activity in patients with schizophrenia. CR in the WCST are associated to higher left frontal activity in controls but not in patients. Probably, there is a RCBF redistribution pattern related to the typical perseveration of schizophrenia which might constitute a phenotypic marker of the illness observable by functional neuroimaging techniques.
authors.affiliation: Division of Child Psychiatry, Columbia-Presbyterian Hospital & New York State Pschiatric Institute, Columbia University, New York, NY, USA.
authors.forename: M
authors.initials: M
authors.lastname: Moreno-Iñiguez
authors.forename: F
authors.initials: F
authors.lastname: Ortuño
authors.forename: R M
authors.initials: RM
authors.lastname: Bonelli
authors.forename: M
authors.initials: M
authors.lastname: Millán
authors.forename: C A
authors.initials: CA
authors.lastname: Soutullo
authors.forename: S
authors.initials: S
authors.lastname: Cervera-Enguiz
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000453:epidemiology* / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon