Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland; Department of Neurology, St James's Hospital, Dublin, Ireland.
Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland.
J Neurol Sci. 2022 May 15;436:120221. doi: 10.1016/j.jns.2022.120221. Epub 2022 Mar 8.
The clinical phenotypes of frontotemporal dementia (FTD) are defined by distinctive clinical features and associated with unique cortical atrophy patterns. Clinical manifestations in FTD however are not solely driven by cortical pathology, but stem from the selective dysfunction of corticobasal circuits, the majority of which are relayed through thalamic nuclei. The objective of this study is the systematic radiological characterisation of thalamic pathology across the clinical spectrum of FTD to describe phenotype-associated thalamic signatures.
170 participants were included in a multimodal, prospective neuroimaging study to evaluate thalamic degeneration at a nuclear, vertex, and morphometric level using a uniform imaging protocol and a multimodal analysis approach.
Patients with behavioural variant FTD (bvFTD), non-fluent variant primary progressive aphasia (nfvPPA), semantic variant primary progressive aphasia (svPPA) and amyotrophic lateral sclerosis-FTD (ALS-FTD) exhibit distinctive thalamic disease-burden profiles with the preferential degeneration of specific thalamic nuclei. While vertex analyses reveal largely overlapping thalamic atrophy patterns, morphometric analyses successfully capture focal intra-thalamic degeneration.
Mirroring selective cortical vulnerability, focal rather than global thalamic atrophy characterises the clinical subtypes of FTD. Thalamic degeneration is a likely contributor to the heterogeneity of clinical manifestations observed in FTD. As thalamic imaging techniques capture different facets of pathological change and differ in their sensitivity to detect distinguishing features, future studies should implement a multimodal approach with complementary MRI techniques.
额颞叶痴呆（FTD）的临床表型由独特的临床特征定义，并与独特的皮质萎缩模式相关。然而，FTD 的临床表现不仅受皮质病理驱动，还源于皮质基底回路的选择性功能障碍，其中大部分通过丘脑核传递。本研究的目的是系统地描述 FTD 临床谱中丘脑病理学的放射学特征，以描述与表型相关的丘脑特征。
170 名参与者纳入了一项多模态、前瞻性神经影像学研究，使用统一的成像方案和多模态分析方法，从核、顶点和形态学水平评估丘脑变性。
行为变异型额颞叶痴呆（bvFTD）、非流利型原发性进行性失语症（nfvPPA）、语义变异型原发性进行性失语症（svPPA）和肌萎缩侧索硬化症-额颞叶痴呆（ALS-FTD）患者表现出独特的丘脑疾病负担特征，特定丘脑核的选择性变性。虽然顶点分析显示出广泛重叠的丘脑萎缩模式，但形态学分析成功地捕捉到了局灶性丘脑内变性。
与选择性皮质易损性相似，局灶性而非全脑的丘脑萎缩是 FTD 临床亚型的特征。丘脑变性可能是 FTD 临床表现异质性的原因之一。由于丘脑成像技术捕捉到了不同的病理变化方面，并且在检测区分特征的敏感性上存在差异，未来的研究应该采用具有互补 MRI 技术的多模态方法。
