Cognition and Behavioural Neurology Section, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, 695011, India.
Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science Pilani, Hyderabad, 500078, India.
Brain Imaging Behav. 2018 Oct;12(5):1221-1228. doi: 10.1007/s11682-017-9784-x.
Fractal dimension (FD) is a quantitative parameter that can characterizes the complexity of human brain tissue. Extensive grey matter (GM) pathology has been previously identified in Frontotemporal dementia (FTD) and its variants. The aim of the present study was to investigate the GM morphometric abnormalities in the behavioral variant FTD (bvFTD) and primary progressive aphasia (PPA) using FD analysis. Twenty-seven bvFTD, 12 PPA and 20 controls were studied. SPM8 was used to segment the brain into GM tissue. Then the FD values were estimated for the GM skeleton, surface and general structure in patients and controls using our previously published algorithm. We found that patients with bvFTD had significant reduction in FD values of skeleton and general structure when compared to controls. In PPA, more significant decrease in FD was noted in the whole brain and left hemisphere skeleton along with left hemisphere general structure. Only the right hemisphere skeleton had a significant correlation with total score of Frontal Systems Behavior Scale (FrSBe). The results showed that the variants of FTD are associated with disease specific morphometric complexity patterns. These results indicate that FD can be used as a biomarker for the structural changes associated with neurodegenerative diseases.
分形维数（FD）是一种可以描述人脑组织结构复杂性的定量参数。在额颞叶痴呆（FTD）及其变体中，已经广泛发现了灰质（GM）病理学。本研究的目的是使用 FD 分析研究行为变异型额颞叶痴呆（bvFTD）和原发性进行性失语症（PPA）的 GM 形态异常。研究了 27 名 bvFTD 患者、12 名 PPA 患者和 20 名对照者。使用 SPM8 将大脑分割为 GM 组织。然后，使用我们之前发表的算法，为患者和对照组的 GM 骨骼、表面和整体结构估计 FD 值。我们发现，与对照组相比，bvFTD 患者的骨骼和整体结构 FD 值显著降低。在 PPA 中，整个大脑和左侧半球骨骼以及左侧半球整体结构的 FD 值下降更为显著。只有右侧半球骨骼与额叶系统行为量表（FrSBe）总分存在显著相关性。研究结果表明，FTD 的变体与特定疾病的形态复杂性模式有关。这些结果表明，FD 可作为与神经退行性疾病相关的结构变化的生物标志物。
