title: Discriminant analysis in schizophrenia and healthy subjects using prefrontal activation during frontal lobe tasks: a near-infrared spectroscopy.
abstract: While psychiatric disorders such as schizophrenia are largely diagnosed on symptomatology, several studies have attempted to determine which biomarkers can discriminate schizophrenia patients from non-patients with schizophrenia. The objective of this study is to assess whether near-infrared spectroscopy (NIRS) measurement can distinguish schizophrenia patients from healthy subjects. Sixty patients with schizophrenia and sixty age- and gender-matched healthy controls were divided into two sequential groups. The concentration change in oxygenated hemoglobin (Delta[oxy-Hb]) was measured in the bilateral prefrontal areas (Fp1-F7 and Fp2-F8) during the Verbal Fluency Test (VFT) letter version and category version, Tower of Hanoi (TOH), Sternberg's (SBT) and Stroop Tasks. In the first group, schizophrenia patients showed poorer task performance on all tasks and less prefrontal cortex activation during all but the Stroop Task compared to healthy subjects. In the second group, schizophrenia patients showed poorer task performance and less prefrontal cortex activation during VFTs and TOH tasks than healthy subjects. We then performed discriminant analysis by a stepwise method using Delta[oxy-Hb] and task performance measures as independent variables. The discriminant analysis in the first group included task performance of TOH, VFT letter and VFT category and Delta[oxy-Hb] of VFT letter. As a result, 88.3% of the participants were correctly classified as being schizophrenic or healthy subjects in the first analysis. The discriminant function derived from the first group correctly assigned 75% of the subjects in the second group. Our findings suggest that NIRS measurement could be applied to differentiate patients with schizophrenia from healthy subjects.
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Osaka, Japan. azechi@psy.med.osaka-u.ac.jp
authors.forename: Michiyo
authors.initials: M
authors.lastname: Azechi
authors.forename: Masao
authors.initials: M
authors.lastname: Iwase
authors.forename: Koji
authors.initials: K
authors.lastname: Ikezawa
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Leonides
authors.initials: L
authors.lastname: Canuet
authors.forename: Ryu
authors.initials: R
authors.lastname: Kurimoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakahachi
authors.forename: Ryouhei
authors.initials: R
authors.lastname: Ishii
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Fukumoto
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Ohi
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yasuda
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kazui
authors.forename: Ryota
authors.initials: R
authors.lastname: Hashimoto
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Takeda
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis; D016002:Discriminant Analysis; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*; D012720:Severity of Illness Index; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D014705:Verbal Behavior