Division of Neurology, Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA.
Epilepsia. 2010 Apr;51(4):519-28. doi: 10.1111/j.1528-1167.2009.02506.x. Epub 2010 Feb 12.
Medial temporal epilepsy (MTLE) is associated with extrahippocampal brain atrophy. The mechanisms underlying brain damage in MTLE are unknown. Seizures may lead to neuronal damage, but another possible explanation is deafferentation from loss of hippocampal connections. This study aimed to investigate the relationship between hippocampal deafferentation and brain atrophy in MTLE.
Three different MRI studies were performed involving 23 patients with unilateral MTLE (8 left and 15 right) and 34 healthy controls: (1) voxel-based morphometry (VBM), (2) diffusion tensor imaging (DTI) and (3) probabilistic tractography (PT). VBM was employed to define differences in regional gray matter volume (GMV) between controls and patients. Voxel-wise analyses of DTI evaluated differences in fractional anisotropy (FA), mean diffusivity (MD) and hippocampal PT. Z-scores were computed for regions-of-interest (ROI) GMV and peri-hippocampal FA and MD (to quantify hippocampal fiber integrity). The relationship between hippocampal deafferentation and regional GMV was investigated through the association between ROI Z scores and hippocampal fiber integrity.
Patients with MTLE exhibited a significant reduction in GMV and FA in perihippocampal and limbic areas. There was a decrease in hippocampal PT in patients with MTLE in limbic areas. A significant relationship between loss of hippocampal connections and regional GMV atrophy was found involving the putamen, pallidum, middle and inferior temporal areas, amygdala and ceberellar hemisphere.
There is a relationship between hippocampal disconnection and regional brain atrophy in MTLE. These results indicate that hippocampal deafferentation plays a contributory role in extrahippocampal brain damage in MTLE.
内侧颞叶癫痫（MTLE）与海马旁脑萎缩有关。导致 MTLE 脑损伤的机制尚不清楚。癫痫发作可能导致神经元损伤，但另一种可能的解释是由于海马连接丢失而导致去传入。本研究旨在探讨 MTLE 中海马去传入与脑萎缩之间的关系。
进行了三项不同的 MRI 研究，涉及 23 例单侧 MTLE 患者（8 例左侧和 15 例右侧）和 34 名健康对照者：（1）体素形态计量学（VBM），（2）弥散张量成像（DTI）和（3）概率追踪（PT）。VBM 用于定义对照组和患者之间区域灰质体积（GMV）的差异。DTI 的体素分析评估了各向异性分数（FA）、平均弥散度（MD）和海马 PT 的差异。计算了感兴趣区（ROI）GMV 和海马旁 FA 和 MD 的 Z 分数（以量化海马纤维完整性）。通过 ROI Z 分数与海马纤维完整性之间的关联，研究了海马去传入与区域性 GMV 之间的关系。
MTLE 患者在海马旁和边缘区域的 GMV 和 FA 明显减少。MTLE 患者的海马 PT 在边缘区域减少。发现海马连接丢失与区域性 GMV 萎缩之间存在显著相关性，涉及纹状体、苍白球、中颞和下颞区、杏仁核和小脑半球。
MTLE 中存在海马去传入与区域性脑萎缩之间的关系。这些结果表明，海马去传入在 MTLE 中海马旁脑损伤中起作用。
