Coan Ana C, Campos Brunno M, Beltramini Guilherme C, Yasuda Clarissa L, Covolan Roberto J M, Cendes Fernando
Department of Neurology, Neuroimaging Laboratory, University of Campinas, Campinas, São Paulo, Brazil.
Epilepsia. 2014 Aug;55(8):1187-96. doi: 10.1111/epi.12670. Epub 2014 Jun 5.
We aimed to investigate patterns of electroencephalography-correlated functional MRI (EEG-fMRI) and subtle structural abnormalities in patients with mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (MTLE-HS) or normal MRI (MTLE-NL).
We evaluated EEG-fMRI acquisition of the 25 patients with diagnosis of MTLE who had interictal epileptiform discharges (IEDs) in the intra-MRI EEG: 13 MTLE-HS and 12 MTLE-NL. fMRI was performed using echo-planar images in a 3T MRI coupled with EEG acquired with 64 MRI-compatible electrodes. In the first level analyses, the time of the IEDs ipsilateral to the epileptogenic zone was used as the paradigm, and four contrasts maps were built according to the variation of the hemodynamic response function (HRF) peaks (0, +3, +5, and +7 s). Second level group analyses were performed combining the contrast maps of MTLE-HS or MTLE-NL patients with each different HRF obtained at the first level. Areas of gray matter atrophy were evaluated with voxel-based morphometry (VBM) in both groups.
MTLE-HS and MTLE-NL had IED-related positive BOLD (posBOLD) detected in the ipsilateral anterior temporal lobe and insula. However, only MTLE-HS had significant posBOLD on contralateral hippocampus and anterior cingulate, whereas MTLE-NL had areas of posBOLD on ipsilateral frontal lobe. Both groups had significant IED-related negBOLD responses in areas of the default mode network (DMN), such as posterior cingulate and precuneus. There was no overlap of both posBOLD and negBOLD and areas of atrophy detected by VBM.
Similar IEDs have different patterns of hemodynamic responses in sub-groups of MTLE. In both MTLE-HS and MTLE-NL, there is a possible suppression of the DMN related to IEDs, as demonstrated by the negBOLD in these areas. The brain areas involved in the interictal related hemodynamic network are not the regions with the most significant gray matter atrophy in MTLE with or without MRI signs of HS.
我们旨在研究内侧颞叶癫痫（MTLE）伴海马硬化（MTLE-HS）或MRI正常（MTLE-NL）患者的脑电图相关功能磁共振成像（EEG-fMRI）模式及细微结构异常。
我们评估了25例诊断为MTLE且在MRI内脑电图中有发作间期癫痫样放电（IEDs）的患者的EEG-fMRI：13例MTLE-HS和12例MTLE-NL。使用3T MRI中的回波平面图像进行功能磁共振成像，并结合64个MRI兼容电极采集的脑电图。在一级分析中，将致痫区同侧IEDs的时间用作范例，并根据血流动力学反应函数（HRF）峰值（0、+3、+5和+7秒）的变化构建四个对比图。进行二级组分析，将MTLE-HS或MTLE-NL患者的对比图与在一级获得的每个不同HRF相结合。两组均采用基于体素的形态学测量（VBM）评估灰质萎缩区域。
MTLE-HS和MTLE-NL在同侧颞叶前部和岛叶检测到与IED相关的正性BOLD（posBOLD）。然而，只有MTLE-HS在对侧海马和前扣带回有显著的posBOLD，而MTLE-NL在同侧额叶有posBOLD区域。两组在默认模式网络（DMN）区域，如后扣带回和楔前叶，均有显著的与IED相关的负性BOLD（negBOLD）反应。VBM检测到的posBOLD和negBOLD以及萎缩区域没有重叠。
相似发作间期癫痫样放电在MTLE亚组中有不同的血流动力学反应模式。在MTLE-HS和MTLE-NL中，如这些区域的negBOLD所示，与发作间期癫痫样放电相关的默认模式网络可能受到抑制。发作间期相关血流动力学网络涉及的脑区不是有或没有HS的MRI征象的MTLE中灰质萎缩最显著的区域。
