Abbott Noelle T, Baker Carolyn J, Chen Conan, Liu Thomas T, Love Tracy E
San Diego State University and University of California San Diego Joint Doctoral Program in Language and Communicative Disorders, San Diego, CA 92182, USA.
Center for Functional MRI and Department of Radiology, University of California San Diego, San Diego, CA 92093, USA.
Brain Sci. 2021 Apr 13;11(4):491. doi: 10.3390/brainsci11040491.
Within the aphasia literature, it is common to link location of lesioned brain tissue to specific patterns of language impairment. This has provided valuable insight into the relationship between brain structure and function, but it does not capture important underlying alterations in function of regions that remain structurally intact. Research has demonstrated that in the chronic stage of aphasia, variable patterns of reduced cerebral blood flow (CBF; hypoperfusion) in structurally intact regions of the brain contribute to persisting language impairments. However, one consistent issue in this literature is a lack of clear consensus on how to define hypoperfusion, which may lead to over- or underestimation of tissue functionality. In the current study, we conducted an exploratory analysis in six individuals with chronic aphasia (>1 year post-onset) using perfusion imaging to (1) suggest a new, individualized metric for defining hypoperfusion; (2) identify the extent of hypoperfused tissue in perilesional bands; and (3) explore the relationship between hypoperfusion and language impairment. Results indicated that our individualized metric for defining hypoperfusion provided greater precision when identifying functionally impaired tissue and its effects on language function in chronic aphasia. These results have important implications for intervention approaches that target intact (or impaired) brain tissue.
在失语症文献中，通常将受损脑组织的位置与特定的语言障碍模式联系起来。这为大脑结构与功能之间的关系提供了宝贵的见解，但它没有捕捉到结构上保持完整的区域功能的重要潜在改变。研究表明，在失语症的慢性阶段，大脑结构完整区域中脑血流量（CBF；灌注不足）的可变模式导致语言障碍持续存在。然而，该文献中一个始终存在的问题是，对于如何定义灌注不足缺乏明确的共识，这可能导致对组织功能的高估或低估。在当前的研究中，我们对6名慢性失语症患者（发病后>1年）进行了一项探索性分析，使用灌注成像来（1）提出一种新的、个体化的灌注不足定义指标；（2）确定病灶周围带灌注不足组织的范围；以及（3）探索灌注不足与语言障碍之间的关系。结果表明，我们用于定义灌注不足的个体化指标在识别慢性失语症中功能受损组织及其对语言功能的影响时提供了更高的精度。这些结果对于针对完整（或受损）脑组织的干预方法具有重要意义。
