Institute of Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore; Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Department of Pharmacology, University of Toronto, Toronto, ON, Canada; Brain and Cognition Discovery Foundation, Toronto, ON, Canada.
J Clin Neurosci. 2021 Dec;94:94-101. doi: 10.1016/j.jocn.2021.10.009. Epub 2021 Oct 16.
Functional near-infrared spectroscopy (fNIRS) provides a direct and objective assessment of cerebral cortex function. It may be used to determine neurophysiological differences between psychiatric disorders with overlapping symptoms, such as major depressive disorder (MDD) and bipolar disorder (BD). Therefore, this preliminary study aimed to compare fNIRS signals during the verbal fluency task (VFT) of English-speaking healthy controls (HC), patients with MDD and patients with BD. Fifteen HCs, 15 patients with MDD and 15 patients with BD were recruited. Groups were matched for age, gender, ethnicity and education. Relative oxy-haemoglobin and deoxy-haemoglobin changes in the frontotemporal cortex was monitored with a 52-channel fNIRS system. Integral values of the frontal and temporal regions were derived as a measure cortical haemodynamic response magnitude. Both patient groups had lower frontal and temporal region integral values than HCs, and patients with MDD had lower frontal region integral value than patients with BD. Moreover, patients could be differentiated from HCs using the frontal and temporal integral values, and patient groups could be differentiated using the frontal region integral values. VFT performance, clinical history and symptom severity were not associated with integral values. These results suggest that prefrontal cortex haemodynamic dysfunction occurs in mood disorders, and it is more extensive in MDD than BD. The fNIRS-VFT paradigm may be a potential tool for differentiating MDD from BD in clinical settings, and these findings need to be verified in a larger sample of English-speaking patients with mood disorders.
功能近红外光谱（fNIRS）提供了对大脑皮层功能的直接客观评估。它可用于确定具有重叠症状的精神疾病（如重度抑郁症（MDD）和双相情感障碍（BD））之间的神经生理差异。因此，本初步研究旨在比较讲英语的健康对照者（HC）、MDD 患者和 BD 患者在言语流畅性任务（VFT）期间的 fNIRS 信号。招募了 15 名 HC、15 名 MDD 患者和 15 名 BD 患者。组间匹配年龄、性别、种族和教育程度。使用 52 通道 fNIRS 系统监测额颞叶皮层的相对氧合血红蛋白和脱氧血红蛋白变化。作为皮质血液动力学反应幅度的衡量标准，得出额区和颞区的积分值。与 HC 相比，两组患者的额区和颞区积分值均较低，MDD 患者的额区积分值低于 BD 患者。此外，可使用额区和颞区积分值将患者与 HC 区分开来，也可使用额区积分值将患者组区分开来。VFT 表现、临床病史和症状严重程度与积分值无关。这些结果表明，情绪障碍患者存在前额叶皮层血液动力学功能障碍，且在 MDD 中比 BD 更为广泛。fNIRS-VFT 范式可能是在临床环境中区分 MDD 和 BD 的潜在工具，这些发现需要在更大的英语语言情绪障碍患者样本中进行验证。
