Chou Po-Han, Koike Shinsuke, Nishimura Yukika, Satomura Yoshihiro, Kinoshita Akihide, Takizawa Ryu, Kasai Kiyoto
Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan; Department of Psychiatry, Taichung Veterans General Hospital, Taichung City, Taiwan;
Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan; Division for Counseling and Support, Office for Mental Health Support, University of Tokyo, Bunkyo-ku, Tokyo, Japan;
Schizophr Bull. 2015 Jan;41(1):268-79. doi: 10.1093/schbul/sbu086. Epub 2014 Jun 19.
Although recent studies have demonstrated that patients with schizophrenia and healthy controls did not differ in the speed of age-related decline in cortical thickness and performances on cognitive tests, hemodynamic changes assessed by functional neuroimaging remain unclear. This study investigated age effects on regional brain cortical activity to determine whether there is similar age-related decline in cortical activity as those observed in cortical thickness and cognitive test performance.
A total of 109 patients with schizophrenia (age range: 16-59 y) and 106 healthy controls (age range: 16-59 y) underwent near-infrared spectroscopy (NIRS) while performing a verbal fluency test (VFT). Group comparison of cortical activity was examined using 2-tailed t tests, adopting the false discovery rate method. The relationship between age and cortical activity was investigated using correlational and multiple regression analyses, adjusting for potential confounding variables. A 2-way ANOVA was conducted to investigate differences in the age effects between diagnostic groups.
The patient group exhibited significantly decreased cortical activity in several regions of the frontotemporal cortices. However, slopes of age-dependent decreases in cortical activity were similar between patients and healthy individuals at the bilateral frontotemporal regions.
Our study showed no significant between-group differences in the age-related decline in cortical activity, as measured by NIRS, over the frontotemporal regions during a VFT. The results of our study may indicate a decrease in cortical activity in a relatively limited period around illness onset rather than continuously progressing over the course of the illness.
尽管近期研究表明，精神分裂症患者与健康对照者在皮质厚度与认知测试表现方面，与年龄相关的衰退速度并无差异，但通过功能神经影像学评估的血流动力学变化仍不明确。本研究调查了年龄对大脑区域皮质活动的影响，以确定皮质活动中是否存在与皮质厚度及认知测试表现中所观察到的类似的与年龄相关的衰退。
共有109名精神分裂症患者（年龄范围：16 - 59岁）和106名健康对照者（年龄范围：16 - 59岁）在进行言语流畅性测试（VFT）时接受了近红外光谱（NIRS）检查。采用双尾t检验并采用错误发现率方法对皮质活动进行组间比较。使用相关性和多元回归分析研究年龄与皮质活动之间的关系，并对潜在的混杂变量进行调整。进行双向方差分析以研究诊断组之间年龄效应的差异。
患者组在额颞叶皮质的几个区域表现出明显降低的皮质活动。然而，在双侧额颞叶区域，患者与健康个体在皮质活动中与年龄相关的下降斜率相似。
我们的研究表明，在VFT期间，通过NIRS测量，额颞叶区域在与年龄相关皮质活动衰退方面，组间无显著差异。我们的研究结果可能表明，在疾病发作前后相对有限的时间段内皮质活动会降低，而非在疾病过程中持续进展。
