Department of Neuropsychiatry, Kochi Medical School, Kohasu, Okoh-cho, Nankoku-shi, Kochi 783-8505, Japan.
Schizophr Res. 2012 Apr;136(1-3):63-9. doi: 10.1016/j.schres.2012.01.039. Epub 2012 Feb 12.
Cognitive impairment and associated frontal lobe dysfunction characterize schizophrenia. The letter fluency test (LFT) has been used as one of the most sensitive measures of the cognitive dysfunction, but the nature and topography of the hypofrontality have yet to be fully elucidated. In this study we used multi-channel near-infrared spectroscopy (NIRS), a recently developed noninvasive functional imaging technique, to measure changes in the concentration of oxygenated hemoglobin in the prefrontal cortices of 31 schizophrenia patients and 26 age- and sex-matched healthy controls during performance of the LFT. The results demonstrated reduced prefrontal cortex activation during the LFT among the schizophrenia patients in comparison with the healthy controls, even after controlling for medication. The hypofrontality was most salient in the prefrontal ventrolateral subregion bilaterally. The reduced activity appeared to be due not only to the lesser magnitude but also to the lesser fluctuation of the changes in oxygenated hemoglobin concentration. The hypofrontality appeared to be independent of the patients' symptomatological manifestations. We concluded that measuring NIRS during performance of the LFT can detect prefrontal lobe dysfunction of schizophrenia patients and may provide a new tool to monitor their treatment and course.
认知障碍和相关的额叶功能障碍是精神分裂症的特征。字母流畅性测试（LFT）已被用作认知功能障碍的最敏感指标之一，但额叶功能低下的性质和分布尚未完全阐明。在这项研究中，我们使用多通道近红外光谱（NIRS），一种最近开发的非侵入性功能成像技术，来测量 31 名精神分裂症患者和 26 名年龄和性别匹配的健康对照者在执行 LFT 期间前额叶皮质中氧合血红蛋白浓度的变化。结果表明，与健康对照组相比，精神分裂症患者在执行 LFT 期间前额叶皮层的激活减少，即使在考虑药物治疗的情况下也是如此。双侧前额叶腹外侧亚区的额叶功能低下最为明显。减少的活动似乎不仅是由于氧合血红蛋白浓度变化的幅度较小，而且是由于波动较小。额叶功能低下似乎与患者的症状表现无关。我们得出结论，在执行 LFT 期间测量 NIRS 可以检测精神分裂症患者的前额叶功能障碍，并可能为监测他们的治疗和病程提供一种新的工具。
