title: Impaired regional hemodynamic response in schizophrenia during multiple prefrontal activation tasks: a two-channel near-infrared spectroscopy study.
abstract: In schizophrenia, dysfunction of the prefrontal cortex (PFC), regarded as a core feature of the disease, has been investigated by different neuroimaging methods. Near infrared spectroscopy (NIRS), a novel neurophysiological method, is being increasingly used in the investigation of frontal dysfunction in schizophrenia. However, NIRS measurements during multiple frontal activation tasks have been rarely reported. The purpose of this study was to compare hemodynamic changes in the PFC between patients with schizophrenia and healthy controls during four different types of frontal lobe tasks using a 2-channel NIRS system. Thirty patients with schizophrenia and thirty age- and gender-matched healthy controls were enrolled in this study. In both groups, changes in oxygenated hemoglobin concentration (Delta[oxyHb]) at the bilateral forehead were measured during Verbal fluency test letter version (VFT-letter), VFT category version, Tower of Hanoi (TOH), the Sternberg and Stroop tasks. Regarding Delta[oxyHb] in PFC, a diagnosis group effect was found for VFT-letter and TOH. Significant negative correlation was found between left Delta[oxyHb] during TOH and negative and cognitive symptom scores in schizophrenia patients. Right Delta[oxyHb] during TOH also showed significant negative correlation with cognitive symptoms scores. No significant correlation between Delta[oxyHb] and clinical characteristics were observed during VFT-letter. These findings suggest that among a battery of frontal lobe tasks administered to schizophrenia patients, VFT-letter and TOH are more sensitive to detect PFC activation, as indicated by Delta[oxyHb] using a 2-channel NIRS. Taken together, these findings and those of previous neuroimaging studies suggest that VFT-letter and TOH might represent possible candidate physiological markers of prefrontal dysfunction in schizophrenia, though extensive testing in clinical settings will be necessary.
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, D3, 2-2 Yamadaoka, Suita, Osaka, 565-0871 Japan. ikezawa@psy.med.osaka-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Ikezawa
authors.forename: Masao
authors.initials: M
authors.lastname: Iwase
authors.forename: Ryouhei
authors.initials: R
authors.lastname: Ishii
authors.forename: Michiyo
authors.initials: M
authors.lastname: Azechi
authors.forename: Leonides
authors.initials: L
authors.lastname: Canuet
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Ohi
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yasuda
authors.forename: Naomi
authors.initials: N
authors.lastname: Iike
authors.forename: Ryu
authors.initials: R
authors.lastname: Kurimoto
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakahachi
authors.forename: Ryuji
authors.initials: R
authors.lastname: Sekiyama
authors.forename: Tetsuhiko
authors.initials: T
authors.lastname: Yoshida
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; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D007839:Functional Laterality; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010108:Oxyhemoglobins / Q000032:analysis; D017397:Prefrontal Cortex / Q000098:blood supply* / Q000503:physiopathology*; D011340:Problem Solving / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D012559:Schizophrenia / Q000150:complications* / Q000473:pathology; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D014706:Verbal Learning / Q000502:physiology; D055815:Young Adult
chemical_list: D010108:Oxyhemoglobins