Spatiotemopral dynamics of epiletiform propagations in surgical specimens taken from patients with intractable epilepsy

癫痫发作活动通常起源于大脑皮层的局部区域，并扩散到大脑的大片区域。这些扩散性异常放电的性质可能解释癫痫患者的临床表型，尽管其传播方式和潜在机制尚不清楚。在本研究中，我们对由各种症状性病变引起的部分癫痫患者手术切除的皮质脑切片进行了黄蛋白荧光成像。诱发性神经活动在致痫组织中瞬间水平地扩散到皮层，但从无癫痫史的脑肿瘤患者身上提取的对照组织中的神经活动仅表现出局部反应。典型地，癫痫样繁殖包括早期和晚期。当刺激强度逐渐变化时，早期表现为全有或全无的行为，而后期表现为逐渐增加的反应。此外，这两个阶段通过不同的皮质层传播，表明它们来自不同的神经回路。形态学检查显示神经元肥大，树突棘缺失，显像。这些发现表明，早期阶段的同步活动可能在人类皮质癫痫异常放电的传播中起关键作用。

Seizure activities often originate from a localized region of the cerebral cortex and spread across large areas of the brain. The properties of these spreading abnormal discharges may account for clinical phenotypes in epilepsy patients, although the manner of their propagation and the underlying mechanisms are not well understood. In the present study we performed flavoprotein fluorescence imaging of cortical brain slices surgically resected from patients with partial epilepsy caused by various symptomatic lesions. Elicited neural activities in the epileptogenic tissue spread horizontally over the cortex momentarily, but those in control tissue taken from patients with brain tumors who had no history of epilepsy demonstrated only localized responses. Characteristically, the epileptiform propagation comprised early and late phases. When the stimulus intensity was changed gradually, the early phase showed an all-or-none behavior, whereas the late phase showed a gradual increase in the response. Moreover, the two phases were propagated through different cortical layers, suggesting that they are derived from distinct neural circuits. Morphological investigation revealed the presence of hypertrophic neurons and loss of dendritic spines, which imaging. These findings indicate that synchronized activities of the early phase may play a key role in spreading abnormal discharges in human cortical epilepsies.