Frontotemporal Disorders Unit and Alzheimer's Disease Research Center, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.
Dement Geriatr Cogn Disord. 2020;49(6):589-597. doi: 10.1159/000511341. Epub 2021 Mar 10.
Although traditionally conceptualized as a language disorder, semantic variant primary progressive aphasia (svPPA) is often accompanied by significant behavioral and affective symptoms which considerably increase disease morbidity. Specifically, these neuropsychiatric symptoms are characterized by breaches in normative socioaffective function, for example, an inability to read social cues, excessive trusting of others, and decreased empathy. Our prior neuroimaging work identified 3 corticolimbic networks anchored in the amygdala, temporal pole, and frontoinsular cortex: an affiliation network, theorized to mediate social approach behavior; an aversion network, theorized to subserve the appraisal of social threat; and a perception network, theorized to mediate the detection of social cues. We hy-pothesized that degeneration of these networks could provide neuroanatomical substrates for socioaffective deficits in svPPA.
We examined hypothesized relationships between subscores on the Social Impairment Rating Scale (SIRS) and atrophy in each of these 3 networks in a group of 16 svPPA patients (using matched cognitively normal controls as a reference).
Consistent with our predictions, the magnitude of atrophy in the affiliation network in svPPA patients correlated with the SIRS subscore of socioemotional detachment, while the magnitude of atrophy in the aversion network in svPPA patients correlated with the SIRS subscore of inappropriate trusting. We did not find the predicted association between perception network atrophy and the SIRS subscore of lack of attention to social cues.
These findings highlight specific socioaffective deficits in svPPA and provide a neuroanatomical basis for these impairments by linking them to networks commonly targeted in this disorder.
尽管语义变异型原发性进行性失语症（svPPA）传统上被认为是一种语言障碍，但它常伴有显著的行为和情感症状，这大大增加了疾病的发病率。具体来说，这些神经精神症状的特征是违反了规范的社会情感功能，例如，无法读懂社交线索、过度信任他人以及同理心降低。我们之前的神经影像学研究确定了 3 个以杏仁核、颞极和额岛皮层为基础的皮质边缘网络：一个联系网络，理论上介导社交接近行为；一个厌恶网络，理论上负责评估社交威胁；以及一个感知网络，理论上介导社交线索的检测。我们假设这些网络的退化可以为 svPPA 的社交情感缺陷提供神经解剖学基础。
我们在一组 16 名 svPPA 患者中（使用匹配的认知正常对照作为参考），检查了社会障碍评分量表（SIRS）的子评分与这 3 个网络中每个网络的萎缩之间的假设关系。
与我们的预测一致，svPPA 患者联系网络的萎缩程度与 SIRS 社交情感脱离子评分相关，而 svPPA 患者厌恶网络的萎缩程度与 SIRS 不适当信任子评分相关。我们没有发现感知网络萎缩与 SIRS 缺乏对社交线索的注意力子评分之间的预期关联。
这些发现突出了 svPPA 中的特定社交情感缺陷，并通过将其与该障碍中常见的网络联系起来，为这些缺陷提供了神经解剖学基础。
