From IRCCS NEUROMED (A.B.), Pozzilli, IS, Italy; Departments of Neurology (N.V.M., G.L.S., M.C.), Radiology (M.C.), Anatomy & Neurobiology (M.C.), and Bioengineering (M.C.), Washington University in St. Louis School of Medicine, MO; Department of Neuroscience (M.C.), University of Padua; and Padua Neuroscience Center (M.C.), Italy.
Neurology. 2019 Jan 8;92(2):e125-e135. doi: 10.1212/WNL.0000000000006738. Epub 2018 Dec 5.
To investigate whether different language deficits are distinguished by the relative strengths of their association with the functional connectivity (FC) at rest of the language network (LN) and cingulo-opercular network (CON) after aphasic stroke.
In a group of patients with acute stroke and left-hemisphere damage, we identified 3 distinct, yet correlated, clusters of deficits including comprehension/lexical semantic, grapheme-phoneme knowledge, and verbal executive functions. We computed partial correlations in which the contributions of a behavioral cluster and network FC of no interest were statistically regressed out.
We observed a double dissociation such that impairment of grapheme-phoneme knowledge was more associated with lower FC of the LN within the left hemisphere than lower FC of the CON, whereas verbal executive deficits were more related to lower FC of the CON than the LN in the left hemisphere. Furthermore, the specific association between language deficits and FC was independent of the amount of structural damage to the LN and CON.
These findings indicate that after a left-hemisphere lesion, the type of language impairment is related to the abnormal pattern of correlated activity in different networks. Accordingly, they extend the concept of a neuropsychological double dissociation from structural damage to functional network abnormalities. Finally, current results strongly argue in favor of the behavioral specificity of intrinsic brain activity after focal structural damage.
探讨在失语症卒中后，不同的语言缺陷是否通过其与语言网络（LN）和扣带-顶叶网络（CON）静息功能连接（FC）的相对强度的关联来区分。
在一组患有急性卒中且左侧半球受损的患者中，我们确定了 3 个不同但相关的缺陷簇，包括理解/词汇语义、字母-音位知识和言语执行功能。我们计算了部分相关，其中行为簇和不感兴趣的网络 FC 的贡献被统计回归。
我们观察到一种双重分离，即字母-音位知识的损害与左侧 LN 的 FC 降低有关，而与 CON 的 FC 降低无关，而言语执行功能的缺陷与 CON 的 FC 降低有关，而与 LN 的 FC 降低无关。此外，语言缺陷与 FC 之间的特定关联独立于 LN 和 CON 的结构损伤程度。
这些发现表明，在左侧半球损伤后，语言损伤的类型与不同网络中相关活动的异常模式有关。因此，它们将神经心理学的双重分离概念从结构损伤扩展到功能网络异常。最后，目前的结果强烈支持在局灶性结构损伤后，内在大脑活动的行为特异性。
