Miki Tomoko, Yokota Osamu, Ishizu Hideki, Kuroda Shigetoshi, Oshima Etsuko, Terada Seishi, Yamada Norihito
Department of Psychiatry, Kinoko Espoir Hospital, Okayama, Japan.
Department of Neuropsychiatry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Neuropathology. 2016 Aug;36(4):388-404. doi: 10.1111/neup.12290. Epub 2016 Mar 11.
Behavioral variant of frontotemporal dementia (bvFTD) is a clinical syndrome characterized mainly by behavioral symptoms due to frontal dysfunction. Major neurodegenerative bases of bvFTD include Pick's disease, frontotemporal lobar degeneration with trans-activation response DNA protein 43-positive inclusions, corticobasal degeneration, and progressive supranuclear palsy. Early disinhibition characterized by socially inappropriate behaviors, loss of manners, and impulsive, rash and careless actions is the most important clinical feature of bvFTD. On the other hand, it was reported that clinical presentations of some Alzheimer's disease cases and patients with psychiatric disorders (e.g., addictive disorders, gambling disorder and kleptomania) often resemble that of bvFTD. Although clinical differentiation of 'true' bvFTD cases with frontotemporal lobar degeneration (FTLD) pathology from mimicking cases without it is not always easy, evaluation of the following features, which were noted in autopsy-confirmed FTLD cases and/or clinical bvFTD cases with circumscribed lobar atrophy, may often provide clues for the diagnosis. (i) The initial symptoms frequently develop at 65 years or younger, and (ii) 'socially inappropriate behaviors' can be frequently interpreted as contextually inappropriate behaviors prompted by environmental visual and auditory stimuli. Taking a detailed history usually reveals various kinds of such behaviors in various situations in everyday life rather than the repetition of a single kind of behavior (e.g., repeated shoplifting). (iii) A correlation between the distribution of cerebral atrophy and neurological and behavioral symptoms is usually observed, and the proportion of FTLD cases with right side-predominant cerebral atrophy may be higher in a psychiatric setting than a neurological setting. Finally, (iv) whether the previous course and the combination of symptoms observed at the first medical visit can be explained by major evolution patterns of clinical syndromes in pathologically confirmed FTLD cases should be considered. These views may provide clues to differentiate FTLD from Alzheimer's disease and to predict a subsequent clinical course and therapeutic interventions needed in the future.
额颞叶痴呆的行为变异型（bvFTD）是一种临床综合征，主要特征是由于额叶功能障碍导致的行为症状。bvFTD的主要神经退行性病变基础包括匹克病、伴有反式激活反应DNA蛋白43阳性包涵体的额颞叶变性、皮质基底节变性和进行性核上性麻痹。以社交不适当行为、礼仪丧失以及冲动、鲁莽和粗心行为为特征的早期去抑制是bvFTD最重要的临床特征。另一方面，据报道，一些阿尔茨海默病病例和精神疾病患者（如成瘾性障碍、赌博障碍和盗窃癖）的临床表现常常与bvFTD相似。虽然将具有额颞叶变性（FTLD）病理的“真正”bvFTD病例与无此病理的模仿病例进行临床鉴别并不总是容易，但对以下特征的评估可能常常为诊断提供线索，这些特征在尸检确诊的FTLD病例和/或具有局限性叶萎缩的临床bvFTD病例中被观察到。（i）初始症状通常在65岁或更年轻时出现，并且（ii）“社交不适当行为”常常可被解释为由环境视觉和听觉刺激引发的情境不适当行为。详细询问病史通常会发现日常生活中各种情况下的此类行为，而不是单一行为的重复（例如，反复行窃）。（iii）通常观察到脑萎缩分布与神经和行为症状之间的相关性，并且在精神科环境中右侧为主的脑萎缩FTLD病例的比例可能高于神经科环境。最后，（iv）应考虑首次就诊时观察到的既往病程和症状组合是否可以由病理确诊的FTLD病例中临床综合征的主要演变模式来解释。这些观点可能为区分FTLD与阿尔茨海默病以及预测未来所需的后续临床病程和治疗干预提供线索。
