The loss and recovery of language functions are still incompletely understood. This longitudinal functional MRI study investigated the neural mechanisms underlying language recovery in patients with post-stroke aphasia putting particular emphasis on the impact of lesion site. To identify patterns of language-related activation, an auditory functional MRI sentence comprehension paradigm was administered to patients with circumscribed lesions of either left frontal (n = 17) or temporo-parietal (n = 17) cortex. Patients were examined repeatedly during the acute (≤1 week, t1), subacute (1-2 weeks, t2) and chronic phase (>6 months, t3) post-stroke; healthy age-matched control subjects (n = 17) were tested once. The separation into two patient groups with circumscribed lesions allowed for a direct comparison of the contributions of distinct lesion-dependent network components to language reorganization between both groups. We hypothesized that activation of left hemisphere spared and perilesional cortex as well as lesion-homologue cortex in the right hemisphere varies between patient groups and across time. In addition, we expected that domain-general networks serving cognitive control independently contribute to language recovery. First, we found a global network disturbance in the acute phase that is characterized by reduced functional MRI language activation including areas distant to the lesion (i.e. diaschisis) and subsequent subacute network reactivation (i.e. resolution of diaschisis). These phenomena were driven by temporo-parietal lesions. Second, we identified a lesion-independent sequential activation pattern with increased activity of perilesional cortex and bilateral domain-general networks in the subacute phase followed by reorganization of left temporal language areas in the chronic phase. Third, we observed involvement of lesion-homologue cortex only in patients with frontal but not temporo-parietal lesions. Fourth, irrespective of lesion location, language reorganization predominantly occurred in pre-existing networks showing comparable activation in healthy controls. Finally, we detected different relationships of performance and activation in language and domain-general networks demonstrating the functional relevance for language recovery. Our findings highlight that the dynamics of language reorganization clearly depend on lesion location and hence open new perspectives for neurobiologically motivated strategies of language rehabilitation, such as individually-tailored targeted application of neuro-stimulation. 10.1093/brain/awaa023_video1 awaa023media1 6133426067001.

中文翻译：

---

左颞顶叶和额叶卒中后语言重组的动态。

语言功能的丢失和恢复仍未完全了解。这项纵向功能性MRI研究研究了卒中后失语症患者语言恢复的神经机制，并特别强调了病变部位的影响。为了确定与语言相关的激活方式，对听觉功能性MRI句子理解范式施予了具有左额叶皮层（n = 17）或颞顶叶皮层（n = 17）局限性病变的患者。在卒中后的急性期（≤1周，t1），亚急性期（1-2周，t2）和慢性期（> 6个月，t3）重复检查患者；健康的年龄匹配的对照组（n = 17）进行了一次测试。分成两个有外伤的患者组可以直接比较不同的依赖病灶的网络成分对两组之间语言重组的贡献。我们假设左半球的剩余部分和病灶周围皮层以及右半球的病灶-皮质皮层的激活在不同患者组之间以及整个时间之间是不同的。此外，我们期望服务于认知控制的领域通用网络独立地有助于语言恢复。首先，我们发现了急性期的全球网络紊乱，其特征是功能性MRI语言的激活减少，包括远离病变的区域（即渗尿）和随后的亚急性网络重新激活（即渗尿的消退）。这些现象是由颞顶病变引起的。其次，我们确定了在亚急性期皮损周围皮层和双侧结构域-通用网络活动增加的病灶独立顺序激活模式，然后在慢性期重组左颞语言区域。第三，我们仅在额叶病变而不是颞顶叶病变的患者中观察到病变-同源皮层。第四，无论病变位置如何，语言重组都主要发生在现有网络中，在健康对照组中显示出可比的激活。最后，我们在语言和领域通用网络中检测到性能和激活的不同关系，证明了语言恢复的功能相关性。我们的研究结果突出表明，语言重组的动力显然取决于病变位置，因此为神经生物学驱动的语言康复策略（例如个性化的神经刺激目标应用）开辟了新的前景。10.1093 /大脑/ awaa023_video1 awaa023media1 6133426067001。