Focal anterior temporal lobe (ATL) degeneration often preferentially affects the left or right hemisphere. While patients with left-predominant ATL (lATL) atrophy show severe anomia and verbal semantic deficits and meet criteria for semantic variant primary progressive aphasia (svPPA) and semantic dementia, patients with early right ATL (rATL) atrophy are more difficult to diagnose as their symptoms are less well understood. Focal rATL atrophy is associated with prominent emotional and behavioral changes, and patients often meet, or go on to meet, criteria for behavioral variant frontotemporal dementia (bvFTD). Uncertainty around early symptoms and absence of an overarching clinicoanatomical framework continue to hinder proper diagnosis and care of patients with rATL disease. Here, we examine a large, well-characterized, longitudinal cohort of patients with rATL-predominant degeneration and propose new criteria and nosology. We identified individuals from our database with a clinical diagnosis of bvFTD or svPPA and a structural MRI (n = 478). Based on neuroimaging criteria, we defined three patient groups: rATL-predominant atrophy with relative sparing of the frontal lobes (n = 46), frontal-predominant atrophy with relative sparing of the rATL (n = 79), and lATL-predominant atrophy with relative sparing of the frontal lobes (n = 75). We compared the clinical, neuropsychological, genetic, and pathological profiles of these groups. In the rATL-predominant group, the earliest symptoms were loss of empathy (27%), person-specific semantic impairment (23%), and complex compulsions and rigid thought process (18%). On testing, this group exhibited greater impairments in Emotional Theory of Mind, recognition of famous people (from names and face), and facial affect naming (despite preserved face perception) than the frontal- and lATL-predominant groups. The clinical symptoms in the first three years of the disease alone were highly sensitive (81%) and specific (84%) differentiating rATL-predominant from frontal-predominant groups. FTLD-TDP (84%) was the most common pathology of the rATL-predominant group. rATL-predominant degeneration is characterized by early loss of empathy and person-specific knowledge, deficits that are caused by progressive decline in semantic memory for concepts of socioemotional relevance. Guided by our results, we outline new diagnostic criteria and propose the name, “semantic behavioral variant frontotemporal dementia” (sbvFTD), which highlights the underlying cognitive mechanism and the predominant symptomatology. These diagnostic criteria will facilitate early identification and care of patients with early, focal rATL degeneration as well as in vivo prediction of FTLD-TDP pathology.

中文翻译：

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右颞叶和社会情感语义：语义行为变异型额颞叶痴呆


局灶性前颞叶 (ATL) 变性通常优先影响左半球或右半球。虽然左侧为主型 ATL (lATL) 萎缩的患者表现出严重的贫血和言语语义缺陷，并且符合语义变异型原发性进行性失语 (svPPA) 和语义性痴呆的标准，但早期右侧 ATL (rATL) 萎缩的患者更难以诊断，因为症状不太为人所知。局灶性 rATL 萎缩与显着的情绪和行为变化相关，患者通常符合或继续符合行为变异型额颞叶痴呆 (bvFTD) 的标准。早期症状的不确定性和总体临床解剖学框架的缺乏继续阻碍 rATL 疾病患者的正确诊断和护理。在这里，我们检查了一个大型的、特征明确的、以 rATL 为主的变性患者的纵向队列，并提出了新的标准和疾病分类学。我们从数据库中确定了具有 bvFTD 或 svPPA 临床诊断和结构 MRI 的个体 (n = 478)。根据神经影像学标准，我们定义了三个患者组：rATL为主的萎缩，额叶相对不受影响（n = 46），额叶为主的萎缩，rATL相对不受影响（n = 79），以及lATL为主的萎缩，额叶相对不受影响（n = 79）。额叶相对较少（n = 75）。我们比较了这些组的临床、神经心理学、遗传和病理学特征。在rATL为主的群体中，最早的症状是共情能力丧失（27%）、特定于人的语义障碍（23%）以及复杂的强迫行为和僵化的思维过程（18%）。 在测试中，该组在心理情感理论、对名人的识别（从名字和面孔）和面部情感命名（尽管保留了面部感知）方面表现出比额叶和左额叶主导组更大的损伤。仅在疾病发生的前三年，临床症状就具有高度敏感性（81%）和特异性（84%），可区分 rATL 为主的群体和额叶为主的群体。 FTLD-TDP (84%) 是 rATL 为主组中最常见的病理。以 rATL 为主的退化的特点是早期丧失同理心和个人特定知识，这是由于社会情感相关概念的语义记忆逐渐下降而导致的缺陷。在我们的研究结果的指导下，我们概述了新的诊断标准，并提出了“语义行为变异型额颞叶痴呆”（sbvFTD）这个名称，它强调了潜在的认知机制和主要症状。这些诊断标准将有助于早期识别和护理早期局灶性 rATL 变性患者以及 FTLD-TDP 病理的体内预测。