Neurorehabilitation and Recovery, Stroke, Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre-Austin Campus, Heidelberg, Victoria, Australia.
Department of Medicine and Neurology, Melbourne Brain Centre, Royal Melbourne Hospital, Parkville, Melbourne, Victoria, Australia.
Neural Plast. 2019 Jul 28;2019:2357107. doi: 10.1155/2019/2357107. eCollection 2019.
One in three survivors of stroke experience poststroke depression (PSD). PSD has been linked with poorer recovery of function and cognition, yet our understanding of potential mechanisms is currently limited. Alterations in resting-state functional MRI have been investigated to a limited extent. Fluctuations in low frequency signal are reported, but it is unknown if interactions are present between the level of depressive symptom score and intrinsic brain activity in varying brain regions.
To investigate potential interaction effects between whole-brain resting-state activity and depressive symptoms in stroke survivors with low and high levels of depressive symptoms.
A cross-sectional analysis of 63 stroke survivors who were assessed at 3 months poststroke for depression, using the Montgomery-Åsberg Depression Rating Scale (MÅDRS-SIGMA), and for brain activity using fMRI. A MÅDRS-SIGMA score of >8 was classified as high depressive symptoms. Fractional amplitude of frequency fluctuations (fALFF) data across three frequency bands (broadband, i.e., ~0.01-0.08; subbands, i.e., slow-5: ~0.01-0.027 Hz, slow-4: 0.027-0.07) was examined.
Of the 63 stroke survivors, 38 were classified as "low-depressive symptoms" and 25 as "high depressive symptoms." Six had a past history of depression. We found interaction effects across frequency bands in several brain regions that differentiated the two groups. The broadband analysis revealed interaction effects in the left insula and the left superior temporal lobe. The subband analysis showed contrasting fALFF response between the two groups in the left thalamus, right caudate, and left cerebellum. Across the three frequency bands, we found contrasting fALFF response in areas within the fronto-limbic-thalamic network and cerebellum.
We provide evidence that fALFF is sensitive to changes in poststroke depressive symptom severity and implicates frontostriatal and cerebellar regions, consistent with previous studies. The use of multiband analysis could be an effective method to examine neural correlates of depression after stroke. The START-PrePARE trial is registered with the Australian New Zealand Clinical Trial Registry, number ACTRN12610000987066.
三分之一的中风幸存者会经历中风后抑郁（PSD）。PSD 与功能和认知恢复较差有关，但我们目前对潜在机制的理解有限。已经对静息状态功能磁共振成像的改变进行了有限的研究。低频信号的波动已经有报道，但尚不清楚抑郁症状评分的水平与不同大脑区域的内在大脑活动之间是否存在相互作用。
研究中风幸存者中低水平和高水平抑郁症状的全脑静息状态活动与抑郁症状之间是否存在潜在的相互作用效应。
对 63 名中风幸存者进行横断面分析，他们在中风后 3 个月时使用蒙哥马利-阿斯伯格抑郁评定量表（MÅDRS-SIGMA）评估抑郁情况，并使用 fMRI 评估大脑活动。MÅDRS-SIGMA 评分>8 被归类为高抑郁症状。对三个频带（宽带，即0.01-0.08；子带，即慢-5：0.01-0.027 Hz，慢-4：0.027-0.07）的分数频率波动（fALFF）数据进行检查。
在 63 名中风幸存者中，38 名被归类为“低抑郁症状”，25 名被归类为“高抑郁症状”。6 人有抑郁病史。我们发现，在几个区分两组的大脑区域中存在跨频带的相互作用效应。宽带分析显示，左岛叶和左颞上回存在相互作用效应。子带分析显示，两组左丘脑、右尾状核和左小脑的 fALFF 反应存在差异。在三个频带中，我们发现额叶-边缘-丘脑-小脑网络和小脑内的区域存在相反的 fALFF 反应。
我们提供的证据表明，fALFF 对中风后抑郁症状严重程度的变化敏感，并提示与先前研究一致的额纹状体和小脑区域。多频带分析的使用可能是一种检查中风后抑郁神经相关的有效方法。START-PrePARE 试验在澳大利亚和新西兰临床试验注册中心注册，编号为 ACTRN12610000987066。
