Irish Muireann, Piguet Olivier, Hodges John R, Hornberger Michael
Neuroscience Research Australia, Barker Street, Randwick, Sydney, Australia; School of Medical Sciences, University of New South Wales, Sydney, Australia; ARC Centre of Excellence in Cognition and its Disorders, Sydney, Australia.
Hum Brain Mapp. 2014 Apr;35(4):1422-35. doi: 10.1002/hbm.22263. Epub 2013 May 14.
Conflicting evidence exists regarding the integrity of episodic memory in the behavioral variant of frontotemporal dementia (bvFTD). Recent converging evidence suggests that episodic memory in progressive cases of bvFTD is compromised to the same extent as in Alzheimer's disease (AD). The underlying neural substrates of these episodic memory deficits, however, likely differ contingent on dementia type. In this study we sought to elucidate the neural substrates of episodic memory performance, across recall and recognition tasks, in both patient groups using voxel-based morphometry (VBM) analyses. We predicted that episodic memory dysfunction would be apparent in both patient groups but would relate to divergent patterns of neural atrophy specific to each dementia type. We assessed episodic memory, across verbal and visual domains, in 19 bvFTD, 18 AD patients, and 19 age- and education-matched controls. Behaviorally, patient groups were indistinguishable for immediate and delayed recall, across verbal and visual domains. Whole-brain VBM analyses revealed regions commonly implicated in episodic retrieval across groups, namely the right temporal pole, right frontal lobe, left paracingulate gyrus, and right anterior hippocampus. Divergent neural networks specific to each group were also identified. Whereas a widespread network including posterior regions such as the posterior cingulate cortex, parietal and occipital cortices was exclusively implicated in AD, the frontal and anterior temporal lobes underpinned the episodic memory deficits in bvFTD. Our results point to distinct neural changes underlying episodic memory decline specific to each dementia syndrome.
关于额颞叶痴呆行为变异型（bvFTD）中情景记忆的完整性，存在相互矛盾的证据。最近越来越多的证据表明，bvFTD进展性病例中的情景记忆受损程度与阿尔茨海默病（AD）相同。然而，这些情景记忆缺陷的潜在神经基质可能因痴呆类型而异。在本研究中，我们试图使用基于体素的形态学测量（VBM）分析，阐明两组患者在回忆和识别任务中情景记忆表现的神经基质。我们预测，两组患者都会出现情景记忆功能障碍，但这将与每种痴呆类型特有的不同神经萎缩模式相关。我们评估了19例bvFTD患者、18例AD患者以及19名年龄和教育程度匹配的对照者在言语和视觉领域的情景记忆。在行为方面，两组患者在言语和视觉领域的即时和延迟回忆方面没有差异。全脑VBM分析揭示了各组在情景检索中普遍涉及的区域，即右侧颞极、右侧额叶、左侧扣带旁回和右侧前海马体。还确定了每组特有的不同神经网络。虽然包括后扣带回皮质、顶叶和枕叶皮质等后部区域的广泛网络仅与AD有关，但额叶和颞叶前部则是bvFTD情景记忆缺陷的基础。我们的结果表明，每种痴呆综合征特有的情景记忆衰退背后存在不同的神经变化。
