The University of Sydney, Brain and Mind Centre, Sydney, New South Wales 2050, Australia.
The University of Sydney, School of Psychology, Sydney, New South Wales 2006, Australia.
Learn Mem. 2019 Jun 17;26(7):262-271. doi: 10.1101/lm.048454.118. Print 2019 Jul.
Converging evidence suggests a critical role for the parietal cortices in episodic memory retrieval. Here, we examined episodic memory performance in Corticobasal Syndrome (CBS), a rare neurodegenerative disorder presenting with early parietal atrophy in the context of variable medial temporal lobe damage. Forty-four CBS patients were contrasted with 29 typical Alzheimer's disease (AD), 29 healthy Controls, and 20 progressive supranuclear palsy patients presenting with brainstem atrophy as a disease control group. Participants completed standardized assessments of verbal episodic memory (learning, delayed recall, and recognition), and underwent structural and diffusion-weighted MRI. Selective delayed recall deficits were evident in the CBS group relative to Controls, at an intermediate level to the stark amnesia displayed by AD, and Control-level performance noted in progressive supranuclear palsy. Considerable variability within the CBS group on delayed recall performance led to the identification of memory-spared ( = 19) and memory-impaired ( = 25) subgroups. Whereas CBS-Spared showed no significant memory deficits, the CBS-Impaired subgroup were indistinguishable from typical AD across all episodic memory measures. Whole-brain voxel-based morphometry analyses implicated fronto-parietal and medial temporal regions in delayed recall performance in both the CBS-Impaired and AD groups. Furthermore, diffusion tensor imaging analyses revealed correlations between delayed recall performance and altered structural connectivity between fronto-parietal and frontotemporal regions in the CBS-Impaired group. Our findings underscore the importance of a distributed brain network including frontal, medial temporal, and parietal brain regions in supporting the capacity for successful episodic memory retrieval.
越来越多的证据表明顶叶皮层在情景记忆检索中起着关键作用。在这里，我们研究了皮质基底节综合征 (CBS) 的情景记忆表现，这是一种罕见的神经退行性疾病，在存在可变的内侧颞叶损伤的情况下，早期表现为顶叶萎缩。44 名 CBS 患者与 29 名典型的阿尔茨海默病 (AD) 患者、29 名健康对照组和 20 名以脑干萎缩为疾病对照组的进行性核上性麻痹患者进行了对比。参与者完成了言语情景记忆（学习、延迟回忆和识别）的标准化评估，并进行了结构和弥散加权 MRI 检查。与对照组相比，CBS 组在选择性延迟回忆方面存在明显缺陷，与 AD 的严重健忘症处于中等水平，与进行性核上性麻痹的对照组水平相当。在 CBS 组中，延迟回忆表现的个体差异较大，导致了记忆保留（ = 19）和记忆受损（ = 25）亚组的确定。尽管 CBS 保留组没有明显的记忆缺陷，但在所有情景记忆测量中，CBS 受损亚组与典型 AD 无法区分。全脑基于体素形态计量学分析表明，在 CBS 受损和 AD 组中，额顶叶和内侧颞叶区域对延迟回忆表现有影响。此外，弥散张量成像分析显示，在 CBS 受损组中，延迟回忆表现与额顶叶和额颞叶之间结构连接的改变之间存在相关性。我们的研究结果强调了包括额叶、内侧颞叶和顶叶在内的分布式大脑网络在支持成功情景记忆检索能力方面的重要性。
