Cerebral Function Unit, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Salford, UK.
Division of Neuroscience and Experimental Psychology, The University of Manchester, Manchester, UK.
J Neurol Neurosurg Psychiatry. 2020 Dec;91(12):1304-1311. doi: 10.1136/jnnp-2020-323969. Epub 2020 Oct 14.
The precise relationship between frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) is incompletely understood. The association has been described as a continuum, yet data suggest that this may be an oversimplification. Direct comparisons between patients who have behavioural variant FTD (bvFTD) with and without ALS are rare. This prospective comparative study aimed to determine whether there are phenotypic differences in cognition and behaviour between patients with FTD-ALS and bvFTD alone.
Patients with bvFTD or FTD-ALS and healthy controls underwent neuropsychological testing, focusing on language, executive functions and social cognition. Behavioural change was measured through caregiver interview. Blood samples were screened for known FTD genes.
23 bvFTD, 20 FTD-ALS and 30 controls participated. On cognitive tests, highly significant differences were elicited between patients and controls, confirming the tests' sensitivities to FTD. bvFTD and FTD-ALS groups performed similarly, although with slightly greater difficulty in patients with ALS-FTD on category fluency and a sentence-ordering task that assesses grammar production. Patients with bvFTD demonstrated more widespread behavioural change, with more frequent disinhibition, impulsivity, loss of empathy and repetitive behaviours. Behaviour in FTD-ALS was dominated by apathy. The repeat expansion was associated with poorer performance on language-related tasks.
Differences were elicited in cognition and behaviour between bvFTD and FTD-ALS, and patients carrying the repeat expansion. The findings, which raise the possibility of phenotypic variation between bvFTD and FTD-ALS, have clinical implications for early detection of FTD-ALS and theoretical implications for the nature of the relationship between FTD and ALS.
额颞叶痴呆（FTD）和肌萎缩侧索硬化症（ALS）之间的确切关系尚未完全阐明。这种关联被描述为一个连续体，但数据表明这可能过于简单化。患有行为变异型额颞叶痴呆（bvFTD）伴或不伴 ALS 的患者之间的直接比较很少。本前瞻性对照研究旨在确定 FTD-ALS 和单纯 bvFTD 患者之间在认知和行为方面是否存在表型差异。
bvFTD 或 FTD-ALS 患者和健康对照者接受神经心理学测试，重点关注语言、执行功能和社会认知。通过照顾者访谈测量行为变化。筛选血液样本以检测已知的 FTD 基因。
23 名 bvFTD、20 名 FTD-ALS 和 30 名对照者参与了研究。在认知测试中，患者与对照组之间存在显著差异，证实了这些测试对 FTD 的敏感性。bvFTD 和 FTD-ALS 组的表现相似，尽管 ALS-FTD 患者在类别流畅性和句子排序任务上的语法产生能力上稍显困难。bvFTD 患者表现出更广泛的行为变化，表现出更多的冲动、冲动、同理心丧失和重复行为。FTD-ALS 患者的行为以冷漠为主。重复扩展与语言相关任务的表现较差相关。
在 bvFTD 和 FTD-ALS 以及携带重复扩展的患者之间，在认知和行为方面存在差异。这些发现增加了 bvFTD 和 FTD-ALS 之间表型变异的可能性，对早期检测 FTD-ALS 具有临床意义，对 FTD 和 ALS 之间关系的本质具有理论意义。
