Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China.
Center of Interventional Radiology and Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China.
J Alzheimers Dis. 2023;94(4):1577-1586. doi: 10.3233/JAD-230048.
Cognitive impairment is the most common clinical manifestation of ischemic leukoaraiosis (ILA), but the underlying neurobiological pathways have not been well elucidated. Recently, it was thought that ILA is a "disconnection syndrome". Disorganized brain connectome were considered the key neuropathology underlying cognitive deficits in ILA patients.
We aimed to detect the disruption of network hubs in ILA patients using a new analytical method called voxel-based eigenvector centrality (EC) mapping.
Subjects with moderate to severe white matters hyperintensities (Fazekas score ≥3) and healthy controls (HCs) (Fazekas score = 0) were included in the study. The resting-state functional magnetic resonance imaging and the EC mapping approach were performed to explore the alteration of whole-brain network connectivity in ILA patients.
Relative to the HCs, the ILA patients exhibited poorer cognitive performance in episodic memory, information processing speed, and executive function (all ps < 0.0125). Additionally, compared with HCs, the ILA patients had lower functional connectivity (i.e., EC values) in the medial parts of default-mode network (i.e., bilateral posterior cingulate gyrus and ventral medial prefrontal cortex [vMPFC]). Intriguingly, the functional connectivity strength at the right vMPFC was positively correlated with executive function deficit in the ILA patients.
The findings suggested disorganization of the hierarchy of the default-mode regions within the whole-brain network in patients with ILA and advanced our understanding of the neurobiological mechanism underlying executive function deficit in ILA.
认知障碍是缺血性脑白质病（ILA）最常见的临床表现，但潜在的神经生物学途径尚未得到很好的阐明。最近，人们认为 ILA 是一种“连接中断综合征”。紊乱的脑连接组被认为是 ILA 患者认知缺陷的关键神经病理学基础。
我们旨在使用一种新的分析方法，即基于体素的特征向量中心度（EC）映射，检测 ILA 患者网络枢纽的中断。
纳入了中重度脑白质高信号（Fazekas 评分≥3）的患者和健康对照组（Fazekas 评分=0）。进行静息态功能磁共振成像和 EC 映射方法，以探讨 ILA 患者全脑网络连接的改变。
与 HCs 相比，ILA 患者在情景记忆、信息处理速度和执行功能方面表现出较差的认知表现（均 p<0.0125）。此外，与 HCs 相比，ILA 患者在默认模式网络的内侧部分（即双侧后扣带回和腹内侧前额叶皮质[vMPFC]）的功能连接（即 EC 值）较低。有趣的是，ILA 患者右侧 vMPFC 的功能连接强度与执行功能缺陷呈正相关。
这些发现表明 ILA 患者全脑网络中默认模式区域的层次结构紊乱，并深入了解了 ILA 患者执行功能缺陷的神经生物学机制。
