Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, 8-11 Queen Square, London, WC1N 3BG, UK.
Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
Alzheimers Res Ther. 2019 May 10;11(1):41. doi: 10.1186/s13195-019-0489-9.
Semantic variant of primary progressive aphasia (svPPA) is a subtype of frontotemporal dementia characterized by asymmetric temporal atrophy.
We investigated the pattern of medial temporal lobe atrophy in 24 svPPA patients compared to 72 controls using novel approaches to segment the hippocampal and amygdalar subregions on MRIs. Based on semantic knowledge scores, we split the svPPA group into 3 subgroups of early, middle and late disease stage.
Early stage: all left amygdalar and hippocampal subregions (except the tail) were affected in svPPA (21-35% smaller than controls), together with the following amygdalar nuclei in the right hemisphere: lateral, accessory basal and superficial (15-23%). On the right, only the temporal pole was affected among the cortical regions. Middle stage: the left hippocampal tail became affected (28%), together with the other amygdalar nuclei (22-26%), and CA4 (15%) on the right, with orbitofrontal cortex and subcortical structures involvement on the left, and more posterior temporal lobe on the right. Late stage: the remaining right hippocampal regions (except the tail) (19-24%) became affected, with more posterior left cortical and right extra-temporal anterior cortical involvement.
With advanced subregions segmentation, it is possible to detect early involvement of the right medial temporal lobe in svPPA that is not detectable by measuring the amygdala or hippocampus as a whole.
语义变异型原发性进行性失语症（svPPA）是额颞叶痴呆的一种亚型，其特征为不对称性颞叶萎缩。
我们使用新方法来研究 24 名 svPPA 患者和 72 名对照者的内侧颞叶萎缩模式，对 MRI 上的海马和杏仁核亚区进行分段。根据语义知识评分，我们将 svPPA 组分为 3 个亚组，即早期、中期和晚期疾病阶段。
早期：svPPA 患者的所有左侧杏仁核和海马亚区（除了尾部）均受到影响（比对照组小 21-35%），右侧的杏仁核核团也受到影响：外侧、附属基底和浅层（15-23%）。右侧的皮质区域仅颞极受到影响。中期：左侧海马尾部受到影响（28%），其他杏仁核核团（22-26%）和右侧 CA4 （15%）也受到影响，左侧出现眶额皮质和皮质下结构受累，右侧出现更靠后的颞叶受累。晚期：右侧剩余的海马区域（除了尾部）（19-24%）受到影响，左侧皮质和右侧额颞叶前皮质的后部也受到更多累及。
通过先进的亚区分段，有可能在 svPPA 中检测到右侧内侧颞叶的早期受累，而这在测量整个杏仁核或海马体时是无法检测到的。
