Remote effects of hippocampal damage on default network connectivity in the human brain
Remote effects of hippocampal damage on default network connectivity in the human brain
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DOI：
10.1007/s00415-009-5233-0
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发表时间：
2009-12-01
影响因子：
6
通讯作者：
Wagner, Kathrin
中科院分区：
文献类型：
--
作者：
Frings, Lars;Schulze-Bonhage, Andreas;Wagner, Kathrin
在健康的人类大脑中，海马体已知与各种大脑皮质区域协同工作。它最近被与大脑的默认网络联系起来，楔前叶是其核心枢纽。我们研究了海马体损伤对楔前叶功能连接模式的远程影响。选取14例选择性单侧海马硬化症癫痫患者和8例健康对照者，在对象定位记忆任务中获取功能性MRI数据。我们评估了楔前叶功能定义区域的功能连通性，该区域显示了默认网络的典型特征：与对照组相比，患者的任务相关失活显著减少。在对照组中，出现了一种与楔前叶基本对称的功能一致性模式，包括典型的默认网络区域，如腹侧内侧前额叶皮层、下顶叶皮层和海马体。默认网络区域的组间差异评估显示，与对照组相比，左侧海马硬化症患者与同侧颞叶中回和海马体的楔前叶连接减少。此外，左侧海马硬化症患者在左侧颞中回、腹侧内侧前额叶皮层和左侧杏仁核的连通性低于右侧海马硬化症患者。我们报告了单侧海马损伤对与人类大脑默认网络相关的远端大脑区域之间功能连接的远程影响。这些初步结果强调了限定病理对功能连接的脑区域的影响。
In the healthy human brain the hippocampus is known to work in concert with a variety of cortical brain regions. It has recently been linked to the default network of the brain, with the precuneus being its core hub. Here we studied the remote effects of damage to the hippocampus on functional connectivity patterns of the precuneus. From 14 epilepsy patients with selective, unilateral hippocampal sclerosis and 8 healthy control subjects, we acquired functional MRI data during performance of an object-location memory task. We assessed functional connectivity of a functionally defined region in the precuneus, which showed the typical properties of the default network: significant task-related deactivation, which was reduced in patients compared to control subjects. In control subjects, a largely symmetrical pattern of functional coherence to the precuneus emerged, including canonical default network areas such as ventral medial prefrontal cortex, inferior parietal cortex, and the hippocampi. Assessment of group differences within the default network areas revealed reduced connectivity to the precuneus in ipsilesional middle temporal gyrus and hippocampus in left hippocampal sclerosis patients compared to controls. Furthermore, left hippocampal sclerosis patients showed lower connectivity than right hippocampal sclerosis patients in left middle temporal gyrus, ventral medial prefrontal cortex, and left amygdala. We report remote effects of unilateral hippocampal damage on functional connectivity between distant brain regions associated with the default network of the human brain. These preliminary results underline the impact of circumscribed pathology on functionally connected brain regions.