Bonakdarpour Borna, Rogalski Emily J, Wang Allan, Sridhar Jaiashre, Mesulam M M, Hurley Robert S
*Cognitive Neurology and Alzheimer's Disease Center †Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL ‡Department of Psychology, Cleveland State University, Cleveland, OH.
Alzheimer Dis Assoc Disord. 2017 Apr-Jun;31(2):101-106. doi: 10.1097/WAD.0000000000000193.
Primary progressive aphasia (PPA) is a clinical syndrome of language decline caused by neurodegenerative pathology. Although language impairments in PPA are typically localized via the morphometric assessment of atrophy, functional changes may accompany or even precede detectable structural alterations, in which case resting state functional connectivity (RSFC) could provide an alternative approach. The goal of this study was to determine whether language network RSFC is reduced in early-stage PPA when atrophy is not prominent. We identified 10 individuals with early-stage agrammatic variant of PPA with no prominent cortical thinning compared with nonaphasic controls. RSFC between 2 nodes of the language network and 2 nodes of the default mode network were compared between agrammatic variant of PPA and healthy control participants. Language network connectivity was comparable with controls among patients with milder agrammatism, but was significantly reduced in patients with more pronounced agrammatism. No group differences were observed in default mode network connectivity, demonstrating specificity of findings. In early stages of PPA when cortical atrophy is not prominent, RSFC provides an alternative method for probing the neuroanatomic substrates of language impairment. RSFC may be of particular utility in studies on early interventions for neurodegenerative disease, either to identify anatomic targets for intervention or as an outcome measure of therapeutic efficacy.
原发性进行性失语（PPA）是一种由神经退行性病变引起的语言功能衰退的临床综合征。尽管PPA中的语言障碍通常通过萎缩的形态学评估来定位，但功能变化可能伴随甚至先于可检测到的结构改变出现，在这种情况下，静息态功能连接（RSFC）可以提供一种替代方法。本研究的目的是确定在萎缩不明显的早期PPA中，语言网络RSFC是否降低。我们确定了10名PPA语法缺失变异型早期患者，与非失语对照相比，他们没有明显的皮质变薄。比较了PPA语法缺失变异型患者和健康对照参与者之间语言网络的两个节点与默认模式网络的两个节点之间的RSFC。在语法缺失较轻的患者中，语言网络连接性与对照组相当，但在语法缺失更明显的患者中显著降低。在默认模式网络连接性方面未观察到组间差异，表明研究结果具有特异性。在PPA的早期阶段，当皮质萎缩不明显时，RSFC为探究语言障碍的神经解剖学基础提供了一种替代方法。RSFC在神经退行性疾病早期干预研究中可能特别有用，既可以确定干预的解剖学靶点，也可以作为治疗效果的一项指标。
