基于Granger因果性的功能磁共振成像对内侧颞叶癫痫活动的研究

Functional Magnetic Resonance Imaging Study on Medial Temporal Lobe Epileptic Activities using Granger Causality

在内侧颞叶癫痫(mTLE)中,内侧颞叶与皮层及皮层下结构参与了癫痫活动的起源与传播。基于Granger因果性(GC)检验方法,对脑电联合功能磁共振(EEG-fMRI)数据进行分析,研究内侧颞叶在mTLE中的作用。以内侧颞叶激活区域为参考区域,计算参考区域与大脑其余每个体素点之间的Granger因果关系,并映射到全脑,形成Granger因果图(GCM)。结果表明,内侧颞叶将癫痫活动传播到外侧颞叶、额叶、顶叶及丘脑等区域,同时受到脑岛、壳核以及丘脑等区域脑活动的影响,提示内侧颞叶在mTLE痫样发放的传播环路中具有关键作用。

The medial temporal lobe, cortex and sub cortex structure participate in the originating and propagating of the epileptic activities in medial temporal lobe epilepsy （mTLE）. In this paper, the data of simultaneous electroencephalogram-functional MRI （EEG-fMRI） were analyzed and the role of medial temporal lobe in mTLE was investigated based on Granger causality. The active region of medial temporal lobe was set as the reference region. And Granger causality between the reference region and each of other voxels was calculated. The results were mapped into the whole brain and a Granger causality map （GCM） was obtained. GCM suggested that medial temporal lobe propagated the neural activity of epilepsy to the regions such as lateral temporal lobe, frontal lobe, parietal lobe, thalamus and so on, and was influenced by such structures as insula, putamen and thalamus. In conclusion, the medial temporal lobe plays a key role in the propagation of epileptic activities.