title: Neural correlates of working memory dysfunction in first-episode schizophrenia patients: an fMRI multi-center study.
abstract: Working memory dysfunction is a prominent impairment in patients with schizophrenia. Our aim was to determine cerebral dysfunctions by means of functional magnetic resonance imaging (fMRI) in a large sample of first-episode schizophrenia patients during a working memory task. 75 first-episode schizophrenia patients and 81 control subjects, recruited within a multi-center study, performed 2- and 0-back tasks while brain activation was measured with fMRI. In order to guarantee comparability between data quality from different scanners, we developed and adopted a standardized, fully automated quality assurance of scanner hard- and software as well as a measure for in vivo data quality. After these quality-control measures had been implemented, 48 patients and 57 controls were included in the final analysis. During attention-related processes, even when the performance between patients and controls was comparable, there was a recognizable emergence of cerebral dysfunctions with hypoactivations in the ventrolateral prefrontal cortex (VLPFC), in the superior temporal cortex and in the thalamus. During working memory performance, parietal hypoactivations, especially in the precuneus, were prominent and were accompanied by poorer performance in patients. A hyperfrontality emerged in the ventrolateral prefrontal cortex. Hence, results point to a dysfunctional ventrolateral prefrontal-parietal network during working memory in patients, suggesting impairments in basic functions such as retrieval, storage and maintenance. The brain activation pattern of this large and significant sample of first-episode schizophrenia patients indicates an imbalanced system failing to adjust the amount of brain activity required in the cerebral network involved in attention and working memory.
authors.affiliation: Department of Psychiatry and Psychotherapy, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany. fschneider@ukaachen.de
authors.forename: Frank
authors.initials: F
authors.lastname: Schneider
authors.forename: Ute
authors.initials: U
authors.lastname: Habel
authors.forename: Martina
authors.initials: M
authors.lastname: Reske
authors.forename: Thilo
authors.initials: T
authors.lastname: Kellermann
authors.forename: Tony
authors.initials: T
authors.lastname: Stöcker
authors.forename: N Jon
authors.initials: NJ
authors.lastname: Shah
authors.forename: Karl
authors.initials: K
authors.lastname: Zilles
authors.forename: Dieter F
authors.initials: DF
authors.lastname: Braus
authors.forename: Andrea
authors.initials: A
authors.lastname: Schmitt
authors.forename: Ralf
authors.initials: R
authors.lastname: Schlösser
authors.forename: Michael
authors.initials: M
authors.lastname: Wagner
authors.forename: Ingo
authors.initials: I
authors.lastname: Frommann
authors.forename: Tilo
authors.initials: T
authors.lastname: Kircher
authors.forename: Alexander
authors.initials: A
authors.lastname: Rapp
authors.forename: Eva
authors.initials: E
authors.lastname: Meisenzahl
authors.forename: Sandra
authors.initials: S
authors.lastname: Ufer
authors.forename: Stephan
authors.initials: S
authors.lastname: Ruhrmann
authors.forename: Renate
authors.initials: R
authors.lastname: Thienel
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sauer
authors.forename: Fritz A
authors.initials: FA
authors.lastname: Henn
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gaebel
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012691:Serial Learning / Q000502:physiology*; D013702:Temporal Lobe / Q000503:physiopathology*; D013788:Thalamus / Q000503:physiopathology*