Fauser Susanne, Schulze-Bonhage Andreas
Epilepsy Center, University of Freiburg, Freiburg, Germany.
Brain. 2006 Jan;129(Pt 1):82-95. doi: 10.1093/brain/awh687. Epub 2005 Nov 29.
Hippocampal sclerosis is often associated with macroscopic or microscopic dysplasia in the temporal neocortex (TN). The relevance of such a dual pathology with regard to epileptogenesis is unclear. This study investigates the role of both pathologies in the generation of ictal and interictal activity. Ictal (113 seizures) and interictal data from invasive EEG recordings with simultaneous depth electrodes in the hippocampus and subdural electrodes over the TN were analysed retrospectively in 12 patients with variable degrees of hippocampal sclerosis and different types of histologically confirmed temporal cortical dysplasia [all male, age at epilepsy onset <1-29 years (mean 9.6 years), age when invasive recordings were performed 6-50 years (mean 28.2 years)]. Of the seizures 41.3% arose from the amygdala/hippocampus complex (AHC), 34.7% from the TN, 22% were simultaneously recorded from AHC and TN (indeterminate seizure onset), and 2% from other regions. In three patients, seizure onset was recorded only from the AHC. In patients with severe hippocampal sclerosis only 12% of the seizures arose from the TN, whereas in patients with mild hippocampal sclerosis 58% arose from the TN. The type of cortical dysplasia, however, did not predict seizure onset in the AHC or TN. Propagation time from the TN to the AHC tended to be shorter (mean 7.4 s) than vice versa (mean 13.7 s). The most common initial ictal patterns in the AHC were rhythmic beta activity (<25 Hz) and repetitive sharp waves, and in the TN were fast activity (>25 Hz) and repetitive sharp waves. The interictal patterns over the TN were similar to those seen over extratemporal focal cortical dysplasias. Simultaneous recordings from the hippocampus and the TN strongly suggest that dysplastic tissue in the TN is often epileptogenic. The quantitative contribution of the hippocampus to seizure generation corresponded with the degree of hippocampal pathology, whereas different subtypes of cortical dysplasia did not affect its relative contribution to seizure generation and even mild forms of dysplasia were epileptogenic.
海马硬化常与颞叶新皮质（TN）的宏观或微观发育异常相关。这种双重病理在癫痫发生中的相关性尚不清楚。本研究调查了这两种病理在发作期和发作间期活动产生中的作用。对12例海马硬化程度不同且组织学证实为不同类型颞叶皮质发育异常的患者（均为男性，癫痫发作起始年龄<1 - 29岁（平均9.6岁），进行侵入性记录时年龄6 - 50岁（平均28.2岁））的侵入性脑电图记录数据进行回顾性分析，这些记录同时使用海马深度电极和TN上方的硬膜下电极，记录了发作期（113次发作）和发作间期数据。在这些发作中，41.3%起源于杏仁核/海马复合体（AHC），34.7%起源于TN，22%同时记录于AHC和TN（发作起始部位不确定），2%起源于其他区域。在3例患者中，仅从AHC记录到发作起始。在海马硬化严重的患者中，仅12%的发作起源于TN，而在海马硬化轻度的患者中，58%的发作起源于TN。然而，皮质发育异常的类型并不能预测AHC或TN的发作起始。从TN到AHC的传播时间往往较短（平均7.4秒），反之则较长（平均13.7秒）。AHC中最常见的初始发作期模式是节律性β活动（<25Hz）和重复性尖波，而TN中是快速活动（>25Hz）和重复性尖波。TN上的发作间期模式与颞叶外局灶性皮质发育异常所见相似。海马和TN的同步记录强烈表明，TN中的发育异常组织通常具有致痫性。海马对发作产生的定量贡献与海马病理程度相对应，而不同亚型的皮质发育异常并不影响其对发作产生的相对贡献，即使是轻度发育异常形式也具有致痫性。
