Reduced Precuneus Deactivation during Object Naming in Patients with Mild Cognitive Impairment, Alzheimer's Disease, and Frontotemporal Lobar Degeneration
Reduced Precuneus Deactivation during Object Naming in Patients with Mild Cognitive Impairment, Alzheimer's Disease, and Frontotemporal Lobar Degeneration
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DOI：
10.1159/000320991
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发表时间：
2010-01-01
影响因子：
2.4
通讯作者：
Huell, Michael
中科院分区：
文献类型：
--
作者：
Frings, Lars;Dressel, Katharina;Huell, Michael
楔前叶是人脑默认网络的一部分，在休息状态下表现出高水平的活动，在与任务相关的行为中表现出较低的活动水平。通常，在功能磁共振成像(FMRI)研究中，后中线区域表现出这种特有的反应。在阿尔茨海默病(AD)和轻度认知障碍(MCI)中，受试者缺乏这种典型的失活。然而，对这些发现的解释被AD的局部病理和萎缩的存在所混淆。与AD不同的是，在早期额颞叶变性(FTLD)患者中，楔前叶实际上没有局部神经病理。在这项研究中，我们展示了一组FTLD患者在对峙命名任务中楔前叶的fMRI信号减少。我们发现，FTLD患者的这种效应(1)与AD和MCI相似，(2)与楔前叶灰质萎缩的程度无关。我们假设，默认网络失活的减少与局部病理无关，而是缺乏连接，这在主要的皮质痴呆FTLD和AD中都会减少。版权所有(C)2010 S.Karger AG，巴塞尔
The precuneus is part of the default network of the human brain, which exhibits a high level of activity during the resting state and lower activity during task-related behavior. Typically, the posterior midline areas show this characteristic response in functional magnetic resonance imaging (fMRI) studies. In Alzheimer's disease (AD) and mild cognitive impairment (MCI), subjects exhibit a lack of this typical deactivation. The interpretation of these findings, however, is obfuscated by the presence of local pathology and atrophy in AD. In contrast to AD, in patients with early frontotemporal lobar degeneration (FTLD), the precuneus is virtually free of local neuropathology. In this study, we demonstrate reduced fMRI signal in the precuneus in a group of patients with FTLD during a confrontation naming task. We show that this effect in FTLD patients was (1) similar to that observed in AD and MCI and (2) not related to the degree of gray matter atrophy in the precuneus. We hypothesize that reduced deactivation of the default network is not related to local pathology but to a lack of connectivity, which decreases in both FTLD and AD, the major cortical dementias. Copyright (C) 2010 S. Karger AG, Basel