PDF(Pubmed)
Abstract：
In patients suffering absence epilepsy, recurring seizures can significantly decrease their quality of life and lead to yet untreatable comorbidities. Absence seizures are characterized by spike-and-wave discharges on the electroencephalogram associated with a transient alteration of consciousness. However, it is still unknown how the brain responds to external stimuli during and outside of seizures. This study aimed to investigate responsiveness to visual and somatosensory stimulation in Genetic Absence Epilepsy Rats from Strasbourg (GAERS), a well-established rat model for absence epilepsy. Animals were imaged under non-curarized awake state using a quiet, zero echo time, functional magnetic resonance imaging (fMRI) sequence. Sensory stimulations were applied during interictal and ictal periods. Whole-brain hemodynamic responses were compared between these two states. Additionally, a mean-field simulation model was used to explain the changes of neural responsiveness to visual stimulation between states. During a seizure, whole-brain responses to both sensory stimulations were suppressed and spatially hindered. In the cortex, hemodynamic responses were negatively polarized during seizures, despite the application of a stimulus. The mean-field simulation revealed restricted propagation of activity due to stimulation and agreed well with fMRI findings. Results suggest that sensory processing is hindered or even suppressed by the occurrence of an absence seizure, potentially contributing to decreased responsiveness during this absence epileptic process.
摘要：
在患有失神癫痫的患者中，反复发作可显著降低患者的生活质量,并导致无法治疗的合并症.失神癫痫发作的特征是脑电图上的尖峰和波放电与短暂的意识改变有关。然而,目前尚不清楚大脑在癫痫发作期间和之外如何对外部刺激做出反应。这项研究旨在研究斯特拉斯堡（GAERS）遗传缺失癫痫大鼠对视觉和体感刺激的反应性，建立良好的失神癫痫大鼠模型。动物在非固化清醒状态下使用安静，零回波时间，功能磁共振成像（fMRI）序列。在发作间期和发作期施加感觉刺激。比较了这两种状态之间的全脑血液动力学反应。此外,我们使用平均场模拟模型来解释不同状态间神经对视觉刺激的反应性变化.在癫痫发作期间，全脑对两种感觉刺激的反应均受到抑制和空间阻碍.在大脑皮层,在癫痫发作期间，血流动力学反应呈负极化，尽管有刺激的应用。平均场模拟显示，由于刺激，活动的传播受到限制，并且与fMRI的发现非常吻合。结果表明，失神发作的发生阻碍甚至抑制了感觉过程，在这种缺位癫痫过程中可能导致反应性降低。
