From the Departments of Psychiatry and Neurology (A.S.A.), Boston Children's Hospital, Harvard Medical School, MA; Departments of Neurology (X.Y., J.S.M., E.J.F., M.K., W.D.G.) and Neuropsychology (L.N.S., M.M.B.), Children's National Hospital; and Department of Psychology (C.J.V.), Georgetown University, Washington, DC.
Neurology. 2022 Jan 18;98(3):e249-e259. doi: 10.1212/WNL.0000000000013071. Epub 2021 Nov 18.
Task fMRI is a clinical tool for language lateralization, but has limitations, and cannot provide information about network-level plasticity. Additional methods are needed to improve the precision of presurgical language mapping. We investigate language resting-state functional connectivity (RS fMRI; FC) in typically developing children (TD) and children with epilepsy. Our objectives were to (1) understand how FC components differ between TD children and those with epilepsy; (2) elucidate how the location of disease (frontal/temporal epilepsy foci) affects FC; and (3) investigate the relationship between age and FC.
Our sample included 55 TD children (mean age 12 years, range 7-18) and 31 patients with focal epilepsy (mean age 13 years, range 7-18). All participants underwent RS fMRI. Using a bilateral canonical language map as target, vertex-wise intrahemispheric FC map and interhemispheric FC map for each participant were computed and thresholded at top 10% to compute an FC laterality index (FCLI; [(L - R)/(L + R)]) of the frontal and temporal regions for both integration (intrahemispheric FC; FCLI) and segregation (interhemispheric FC; FCLI) maps.
We found FC differences in the developing language network based on disease, seizure foci location, and age. Frontal and temporal FCLI was different between groups (t[84] = 2.82, < 0.01; t[84] = 4.68, < 0.01, respectively). Frontal epilepsy foci had the largest differences from TD (Cohen frontal FCLI = 0.84, FCLI = 0.51; temporal FCLI = 1.29). Development and disease have opposing influences on the laterality of FC based on groups. In the frontal foci group, FCLI decreased with age ( = -0.42), whereas in the temporal foci group, FCLI increased with age ( = 0.40). Within the epilepsy group, increases in right frontal integration FCLI relates to increased right frontal task activation in our mostly left language dominant group ( = 0.52, < 0.01). Language network connectivity is associated with higher verbal intelligence in children with epilepsy ( = 0.45, < 0.05).
These findings lend preliminary evidence that FC reflects network plasticity in the form of adaptation and compensation, or the ability to recruit support and reallocate resources within and outside of the traditional network to compensate for disease. FC expands on task-based fMRI and provides complementary and potentially useful information about the language network that is not captured using task-based fMRI alone.
任务 fMRI 是一种用于语言侧化的临床工具，但存在局限性，无法提供关于网络水平可塑性的信息。需要额外的方法来提高术前语言映射的精度。我们研究了正常发育儿童（TD）和癫痫儿童的语言静息态功能连接（RS fMRI；FC）。我们的目标是：（1）了解 TD 儿童和癫痫儿童之间的 FC 成分有何不同；（2）阐明疾病的位置（额叶/颞叶癫痫病灶）如何影响 FC；（3）研究年龄与 FC 的关系。
我们的样本包括 55 名 TD 儿童（平均年龄 12 岁，范围 7-18 岁）和 31 名局灶性癫痫患者（平均年龄 13 岁，范围 7-18 岁）。所有参与者均接受 RS fMRI 检查。使用双侧标准语言图作为目标，对每位参与者进行顶点间半球内 FC 图和半球间 FC 图计算，并在顶部 10%处进行阈值处理，以计算额叶和颞叶区域的 FC 侧化指数（FCLI；[(L-R)/(L+R)])，用于整合（半球内 FC；FCLI）和分离（半球间 FC；FCLI）图。
我们根据疾病、癫痫灶位置和年龄发现了发育中语言网络的 FC 差异。组间 FC 存在差异（t[84] = 2.82， < 0.01；t[84] = 4.68， < 0.01，分别）。额叶和颞叶 FCLI 不同（t[84] = 2.82， < 0.01；t[84] = 4.68， < 0.01，分别）。与 TD 相比，额叶癫痫灶的差异最大（Cohen 额叶 FCLI = 0.84，FCLI = 0.51；颞叶 FCLI = 1.29）。发展和疾病对 FC 的偏侧性有相反的影响，这取决于组。在额叶病灶组中，FCLI 随年龄下降（ = -0.42），而在颞叶病灶组中，FCLI 随年龄增加（ = 0.40）。在癫痫组中，右额前整合 FCLI 的增加与我们以左侧语言优势为主的组中右额前任务激活的增加有关（ = 0.52， < 0.01）。癫痫儿童的语言网络连通性与较高的言语智力相关（ = 0.45， < 0.05）。
这些发现初步证明 FC 反映了网络可塑性的形式，即适应和补偿，或者是在传统网络内外招募支持和重新分配资源的能力，以补偿疾病。FC 扩展了基于任务的 fMRI，并提供了关于语言网络的补充且可能有用的信息，这些信息不能仅通过基于任务的 fMRI 获得。
