Takizawa Ryu, Kasai Kiyoto, Kawakubo Yuki, Marumo Kohei, Kawasaki Shingo, Yamasue Hidenori, Fukuda Masato
Department of Neuropsychiatry, Graduate school of Medicine, The University of Tokyo, Tokyo, Japan.
Schizophr Res. 2008 Feb;99(1-3):250-62. doi: 10.1016/j.schres.2007.10.025. Epub 2007 Dec 11.
Functional neuroimaging studies to date have shown prefrontal dysfunction during executive tasks in schizophrenia. However, relationships between hemodynamic response in prefrontal sub-regions and clinical characteristics have been unclear. The objective of this study is to evaluate prefrontal hemodynamic response related to an executive task in schizophrenia and to assess the relationship between activation in the prefrontal sub-regions and clinical status. Fifty-five subjects with schizophrenia and age- and gender-matched 70 healthy subjects were recruited for this case-control study in a medical school affiliated hospital in the Tokyo metropolitan area, Japan. We measured hemoglobin concentration changes in the prefrontal (dorsolateral, ventrolateral, and frontopolar regions) and superior temporal cortical surface area during verbal fluency test using 52-channel near-infrared spectroscopy, which enables real-time monitoring of cerebral blood volumes in the cortical surface area under a more restraint-free environment than positron emission tomography or functional magnetic resonance imaging. The two groups showed distinct spatiotemporal pattern of oxy-hemoglobin concentration change during verbal fluency test. Schizophrenia patients were associated with slower and reduced increase in prefrontal activation than healthy controls. In particular, reduced activations of the frontopolar region, rather than lateral prefrontal or superior temporal regions, showed significant positive correlations with lower global assessment of functioning scores in the patient group, although task performance was not significantly associated with the scores. These results suggest that reduced frontopolar cortical activation is associated with functional impairment in patients with schizophrenia and that near-infrared spectroscopy may be an efficient clinical tool for monitoring these characteristics.
迄今为止，功能神经影像学研究表明，精神分裂症患者在执行任务时存在前额叶功能障碍。然而，前额叶亚区域的血流动力学反应与临床特征之间的关系尚不清楚。本研究的目的是评估精神分裂症患者与执行任务相关的前额叶血流动力学反应，并评估前额叶亚区域激活与临床状态之间的关系。在日本东京都会区一所医学院附属医院，招募了55名精神分裂症患者以及70名年龄和性别匹配的健康受试者，进行这项病例对照研究。我们使用52通道近红外光谱仪，在言语流畅性测试期间测量前额叶（背外侧、腹外侧和额极区域）和颞上叶皮质表面积的血红蛋白浓度变化，与正电子发射断层扫描或功能磁共振成像相比，近红外光谱仪能够在更无约束的环境下实时监测皮质表面积的脑血容量。两组在言语流畅性测试期间显示出不同的氧合血红蛋白浓度变化的时空模式。与健康对照组相比，精神分裂症患者前额叶激活的增加较慢且减少。特别是，额极区域的激活减少，而非外侧前额叶或颞上叶区域，与患者组较低的总体功能评估得分呈显著正相关，尽管任务表现与得分无显著关联。这些结果表明，额极皮质激活减少与精神分裂症患者的功能损害有关，并且近红外光谱仪可能是监测这些特征的有效临床工具。
