颞叶癫痫的结构和功能影像学异常谱。

The spectrum of structural and functional imaging abnormalities in temporal lobe epilepsy.

机构信息

From the Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.

Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.

出版信息

Ann Neurol. 2016 Jul;80(1):142-53. doi: 10.1002/ana.24691. Epub 2016 Jun 9.

DOI:10.1002/ana.24691

PMID:27228409

Abstract

OBJECTIVE

Although most temporal lobe epilepsy (TLE) patients show marked hippocampal sclerosis (HS) upon pathological examination, 40% present with no significant cell loss but gliotic changes only. To evaluate effects of hippocampal pathology on brain structure and functional networks, we aimed at dissociating multimodal magnetic resonance imaging (MRI) characteristics in patients with HS (TLE-HS) and those with gliosis only (TLE-G).

METHODS

In 20 TLE-HS, 19 TLE-G, and 25 healthy controls, we carried out a novel MRI-based hippocampal subfield surface analysis that integrated volume, T2 signal intensity, and diffusion markers with seed-based hippocampal functional connectivity.

RESULTS

Compared to controls, TLE-HS presented with marked ipsilateral atrophy, T2 hyperintensity, and mean diffusivity increases across all subfields, whereas TLE-G presented with dentate gyrus hypertrophy, focal increases in T2 intensity and mean diffusivity. Multivariate assessment confirmed a more marked ipsilateral load of anomalies across all subfields in TLE-HS, whereas anomalies in TLE-G were restricted to the subiculum. A between-cohort dissociation was independently suggested by resting-state functional connectivity analysis, revealing marked hippocampal decoupling from anterior and posterior default mode hubs in TLE-HS, whereas TLE-G did not differ from controls. Back-projection connectivity analysis from cortical targets revealed consistently decreased network embedding across all subfields in TLE-HS, while changes in TLE-G were limited to the subiculum. Hippocampal disconnectivity strongly correlated to T2 hyperintensity and marginally to atrophy.

INTERPRETATION

Multimodal MRI reveals diverging structural and functional connectivity profiles across the TLE spectrum. Pathology-specific modulations of large-scale functional brain networks lend novel evidence for a close interplay of structural and functional disruptions in focal epilepsy. Ann Neurol 2016;80:142-153.

摘要

目的

尽管大多数颞叶癫痫（TLE）患者在病理检查时表现出明显的海马硬化（HS），但仍有 40%的患者没有明显的细胞丢失，只有胶质改变。为了评估海马病理学对脑结构和功能网络的影响，我们旨在区分 HS（TLE-HS）和仅有胶质改变（TLE-G）患者的多模态磁共振成像（MRI）特征。

方法

在 20 例 TLE-HS、19 例 TLE-G 和 25 例健康对照者中，我们进行了一种新的基于 MRI 的海马亚区表面分析，该分析整合了体积、T2 信号强度和扩散标记物与基于种子的海马功能连接。

结果

与对照组相比，TLE-HS 表现为同侧明显萎缩、所有亚区的 T2 高信号和平均弥散度增加，而 TLE-G 表现为齿状回肥大、亚区局部 T2 强度和平均弥散度增加。多变量评估证实 TLE-HS 所有亚区的同侧异常负荷更明显，而 TLE-G 的异常仅限于下托。静息状态功能连接分析提示在 TLE-HS 中存在明显的海马与前、后默认模式中心的分离，而 TLE-G 与对照组无差异。从皮质靶区的回溯连接分析显示 TLE-HS 所有亚区的网络嵌入均明显减少，而 TLE-G 的变化仅限于下托。海马失连接与 T2 高信号强烈相关，与萎缩有一定的相关性。