Magnetic resonance imaging in the study of the lithium-pilocarpine model of temporal lobe epilepsy in adult rats
Magnetic resonance imaging in the study of the lithium-pilocarpine model of temporal lobe epilepsy in adult rats
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DOI：
10.1046/j.1528-1157.2002.11301.x
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发表时间：
2002-04-01
期刊：
影响因子：
5.6
通讯作者：
Namer, IJ
中科院分区：
文献类型：
--
作者：
Roch, C;Leroy, C;Namer, IJ
目的：在颞叶癫痫中，海马区硬化是癫痫的原因还是后果，目前尚不清楚。用磁共振成像(MRI)研究锂-匹罗卡品癫痫模型大鼠癫痫模型中病灶的时间演变，以确定慢性癫痫出现前的进行性形态变化。方法：在磁共振扫描仪上以4.7T的速度进行扫描，用T2和T1加权序列跟踪注射Gd前后的病变演变，从2 h到9周。结果：癫痫持续状态(SE)后2 h，仅丘脑可见血脑屏障的破坏；SE后24 h杏仁核、梨状皮质和内嗅皮质出现水肿，并伴有广泛的神经元丢失，5天后逐渐消失。在慢性期，所有动物再次出现皮质信号；该信号对应于胶质增生，在胶质纤维酸性蛋白(GFAP)免疫组织化学染色切片上显示为肥大的星形胶质细胞，突起增厚。在海马区，组织病理学和T2加权信号之间的相关性强调了从SE后2天开始的进行性萎缩和硬化的构成。结论：这些数据显示了皮质的反应性，这是导致癫痫发展的初始步骤和可能导致自发癫痫发作的晚期胶质增生的特征。此外，海马区硬化症似乎逐渐恶化，可能是癫痫活动的原因和后果。
Purpose: In temporal lobe epilepsy, it remains to be clarified whether hippocampal sclerosis is the cause or the consequence of epilepsy. We studied the temporal evolution of the lesions in the lithium-pilocarpine model of epilepsy in the rat with magnetic resonance imaging (MRI) to determine the progressive morphologic changes occurring before the appearance of chronic epilepsy.Methods: MRI was performed on an MR scanner operating at 4.7 T. We followed the evolution of lesions using T-2- and T-1-weighted sequences before and after the injection of gadolinium from 2 h to 9 weeks.Results: At 2 h after status epilepticus (SE), a blood-brain barrier breakdown could be observed only in the thalamus; it had disappeared by 6 h. At 24 h after SE, edema was present in the amygdala and the piriform and entorhinal cortices together with extensive neuronal loss; it disappeared progressively over a 5-day period. During the chronic phase, a cortical signal reappeared in all animals; this signal corresponded to gliosis, which appeared on glial fibrillary acidic protein (GFAP) immunohistochemically stained sections as hypertrophic astrocytes with thickened processes. In the hippocampus, the correlation between histopathology and T-2-weighted signal underscored the progressive constitution of atrophy and sclerosis, starting 2 days after SE.Conclusions: These data show the reactivity of the cortex that characterizes the initial step leading to the development of epilepsy and the late gliosis that could result from the spontaneous seizures. Moreover, it appears that hippocampal sclerosis progressively worsened and could be both the cause and the consequence of epileptic activity.