Meijboom R, Steketee R M E, de Koning I, Osse R J, Jiskoot L C, de Jong F J, van der Lugt A, van Swieten J C, Smits M
Radiology and Nuclear Medicine, Erasmus MC - University Medical Centre, Rotterdam, The Netherlands.
Neuropsychology, Erasmus MC - University Medical Centre, Rotterdam, The Netherlands.
Eur Radiol. 2017 Apr;27(4):1352-1360. doi: 10.1007/s00330-016-4490-4. Epub 2016 Jul 19.
Phenocopy frontotemporal dementia (phFTD) is a rare and poorly understood clinical syndrome. PhFTD shows core behavioural variant FTD (bvFTD) symptoms without associated cognitive deficits and brain abnormalities on conventional MRI and without progression. In contrast to phFTD, functional connectivity and white matter (WM) microstructural abnormalities have been observed in bvFTD. We hypothesise that phFTD belongs to the same disease spectrum as bvFTD and investigated whether functional connectivity and microstructural WM changes similar to bvFTD are present in phFTD.
Seven phFTD patients without progression or alternative psychiatric diagnosis, 12 bvFTD patients and 17 controls underwent resting state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI). Default mode network (DMN) connectivity and WM measures were compared between groups.
PhFTD showed subtly increased DMN connectivity and subtle microstructural changes in frontal WM tracts. BvFTD showed abnormalities in similar regions as phFTD, but had lower increased DMN connectivity and more extensive microstructural WM changes.
Our findings can be interpreted as neuropathological changes in phFTD and are in support of the hypothesis that phFTD and bvFTD may belong to the same disease spectrum. Advanced MRI techniques, objectively identifying brain abnormalities, would therefore be potentially suited to improve the diagnosis of phFTD.
• PhFTD shows brain abnormalities that are similar to bvFTD. • PhFTD shows increased functional connectivity in the parietal default mode network. • PhFTD shows microstructural white matter abnormalities in the frontal lobe. • We hypothesise phFTD and bvFTD may belong to the same disease spectrum.
表型模仿性额颞叶痴呆（phFTD）是一种罕见且了解甚少的临床综合征。phFTD表现出典型行为变异型额颞叶痴呆（bvFTD）症状，但无相关认知缺陷，传统MRI上无脑异常表现，且病情无进展。与phFTD不同，bvFTD中已观察到功能连接和白质（WM）微观结构异常。我们假设phFTD与bvFTD属于同一疾病谱，并研究phFTD中是否存在与bvFTD相似的功能连接和WM微观结构变化。
7例无病情进展或无其他精神疾病诊断的phFTD患者、12例bvFTD患者和17名对照者接受静息态功能MRI（rs-fMRI）和扩散张量成像（DTI）检查。比较各组间默认模式网络（DMN）连接性和WM测量值。
phFTD显示DMN连接性略有增加，额叶WM束有细微的微观结构变化。bvFTD在与phFTD相似的区域出现异常，但DMN连接性增加程度较低，WM微观结构变化更广泛。
我们的研究结果可解释为phFTD中的神经病理学变化，支持phFTD和bvFTD可能属于同一疾病谱的假设。因此，能够客观识别脑异常的先进MRI技术可能适合改善phFTD的诊断。
• phFTD显示出与bvFTD相似的脑异常。• phFTD在顶叶默认模式网络中显示功能连接增加。• phFTD在额叶显示微观结构白质异常。• 我们假设phFTD和bvFTD可能属于同一疾病谱。
