NIRS and MEG study on brain mechanisms of social cognitive deficits in schizophrenia and mood disorders

目的：近红外光谱（NIBS）是最近发展起来的一项技术，可在床边无创地监测脑血容量变化。近红外光谱已越来越多地应用于精神病学，如人格、衰老和精神疾病的功能神经成像研究。采用多通道近红外光谱仪研究了精神分裂症、单极抑郁症和双相抑郁症患者的额叶功能特征。方法：25例精神分裂症患者、11例单极抑郁症患者、17例双相抑郁症患者及其年龄和性别匹配的健康受试者在填写书面知情同意书后参与研究。在单词流畅性任务和手指敲击任务中，使用两套24通道近红外光谱仪（日立医疗公司）每0.1 s监测一次氧血红蛋白浓度（[氧- hb]）的变化，探针放置在受试者的额叶和双侧颞区。结果：三个精神病组在单词流畅性任务中表现出与对照组不同的[oxy-Hb]变化模式，尽管他们的任务表现相同。精神分裂症组在任务期间[oxy-Hb]增加减少，任务后[oxy-Hb]再次增加，单极抑郁症组[oxy-Hb]增加较小，双相抑郁症组[oxy-Hb]增加相似但延迟。结论：观察到的[oxy-Hb]变化的差异提示了精神分裂症、单极抑郁症和双相抑郁症额叶功能反应性的时间过程特征：低效、减少和保留但延迟激活。近红外光谱已经揭示了额叶激活的详细时间过程，在不久的将来可以用作诊断和治疗精神疾病的临床实验室测试。

Objectives: Near-infrared spectroscopy (NIBS) is a recently developed technology that monitors cerebral blood volume changes noninvasively in bedside setting. NIRS has been increasingly employed in psychiatry such as functional neuroimaging studies of personality, aging, and psychiatric disorders. Characteristics of frontal lobe function were investigated using multichannel NIRS machines in schizophrenia, unipolar depression, and bipolar depression.Methods: Twenty-five patients with schizophrenia, eleven patients with unipolar depression, seventeen patients with bipolar depression, and their age- and sex-matched healthy subjects participated in the study after giving their written informed consents. Changes of oxy-hemoglobin concentration ( [oxy-Hb] ) were monitored every 0.1 s during a word fluency task and a finger-tapping task using two sets of 24-channel NIRS machines (Hitachi Medical Co.) with the probes placed on the subjects' frontal and the bilateral temporal regions.Results: Three psychiatric groups demonstrated different patterns of [oxy-Hb] changes from those in the control group during the word fluency task although their task performances were equal. The schizophrenic group was characterized by reduced [oxy-Hb] increase during the task period followed by [oxy-Hb] re-increase during the post-task period, the unipolar depression group by smaller [oxy-Hb] increase, and the bipolar depression group by comparable but delayed [oxy-Hb] increase.Conclusions: The observed differences of [oxy-Hb] changes suggest the characteristics in time courses of reactivity of frontal lobe function: inefficient, reduced, and preserved but delayed activation in schizophrenia, unipolar depression, and bipolar depression, respectively. NIRS has revealed detailed time-courses of frontal lobe activation, and can be employed as a clinical laboratory test for diagnosis and treatment of psychiatric disorders in the near future.