The BOLD response to interictal epileptiform discharges
The BOLD response to interictal epileptiform discharges
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DOI：
10.1006/nimg.2002.1164
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发表时间：
2002-11-01
期刊：
影响因子：
5.7
通讯作者：
Gotman, J
中科院分区：
文献类型：
--
作者：
Bénar, CG;Gross, DW;Gotman, J
我们研究了单次事件和平均BOLD反应脑电图发作间期癫痫放电（IEDs）在4例局灶性癫痫，连续EEG-fMRI在80分钟的会议。通过将每个体素处的BOLD信号与预期信号的模型进行比较来执行激活区域的检测。由于对IED的BOLD反应知之甚少，我们用对简短听觉事件的反应（G。H.格洛弗，1999，神经影像9，416-429）。对于每个激活区域，我们获得了完整会话的BOLD信号的时间过程，并计算了IED的实际平均血流动力学反应函数（HRF）。在四名患者中的两名中，我们观察到对单一IED的明确BOLD反应。所有患者的平均反应由6 - 7 s的正波瓣峰值和3例患者的负下冲组成。患者之间的平均HRF在幅度和形状上存在重要差异。3例患者的平均HRF呈现比格洛弗模型更宽的正叶，2例患者呈现更长的下冲。有一个显着的相似性，在形状的HRF跨区域的患者呈现多个激活位点。个体BOLD反应的幅度与相应EEG棘波的幅度之间没有明显的相关性。较长的HRF的可能性，可用于提高同步EEG-fMRI激活的统计检测。患者平均HRF的变异性可能部分反映了不同的病理生理机制。(C)2002 Elsevier Science（美国）。
We studied single-event and average BOLD responses to EEG interictal epileptic discharges (IEDs) in four patients with focal epilepsy, using continuous EEG-fMRI during 80-min sessions. The detection of activated areas was performed by comparing the BOLD signal at each voxel to a model of the expected signal. Since little is known about the BOLD response to IEDs, we modeled it with the response to brief auditory events (G. H. Glover, 1999, NeuroImage 9, 416-429). For each activated area, we then obtained the time course of the BOLD signal for the complete session and computed the actual average hemodynamic response function (HRF) to IEDs. In two of four patients, we observed clear BOLD responses to single IEDs. The average response was composed of a positive lobe peaking between 6 and 7 s in all patients and a negative undershoot in three patients. There were important variations in amplitude and shape between average HRFs across patients. The average HRF presented a wider positive lobe than the Glover model in three patients and a longer undershoot in two. There was a remarkable similarity in the shape of the HRF across areas for patients presenting multiple activation sites. There was no clear correlation between the amplitude of individual BOLD responses and the amplitude of the corresponding EEG spike. The possibility of a longer HRF could be used to improve statistical detection of activation in simultaneous EEG-fMRI. The variability in average HRFs across patients could reflect in part different pathophysiological mechanisms. (C) 2002 Elsevier Science (USA).