Left hemisphere regions are critical for language in the face of early left focal brain injury
Left hemisphere regions are critical for language in the face of early left focal brain injury
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DOI：
10.1093/brain/awq104
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发表时间：
2010-06-01
期刊：
影响因子：
14.5
通讯作者：
Small, Steven L.
中科院分区：
文献类型：
--
作者：
Raja Beharelle, Anjali;Dick, Anthony Steven;Small, Steven L.
关于早期中风及其对语言发育的影响的主要理论是，早期左半球损伤触发代偿过程，使右半球承担主导语言功能，这被认为是早期中风后观察到的接近正常的语言发育的基础。为了验证这一理论，我们使用功能性磁共振成像来检查参与者在类别流畅性过程中的大脑活动，这些参与者患有持续的产前或围产期左半球中风（n = 25）和神经学正常的兄弟姐妹（n = 27）。在发育正常的儿童中，类别流畅性任务的表现主要涉及左额叶和侧颞区，而右半球结构的参与较少。在我们的队列研究中，早期中风患者的语言发育参与者的表达和接受语言技能与支持神经正常儿童语言处理的相同左下额叶区域的活动相关。这与脑损伤的数量或损伤位于经典皮层语言处理区域的程度无关。在左侧和右侧上级颞下顶叶区域的双边激活的参与者有更好的语言功能比那些主要是左侧或右侧单侧激活。在我们的研究中，左下额叶和双侧颞叶受累所带来的优势支持了典型神经语言组织的强烈倾向，尽管存在介入性损伤，并反对表明右半球在早期损伤后完全适应语言功能的模型。
A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we used functional magnetic resonance imaging to examine brain activity during category fluency in participants who had sustained pre- or perinatal left hemisphere stroke (n = 25) and in neurologically normal siblings (n = 27). In typically developing children, performance of a category fluency task elicits strong involvement of left frontal and lateral temporal regions and a lesser involvement of right hemisphere structures. In our cohort of atypically developing participants with early stroke, expressive and receptive language skills correlated with activity in the same left inferior frontal regions that support language processing in neurologically normal children. This was true independent of either the amount of brain injury or the extent that the injury was located in classical cortical language processing areas. Participants with bilateral activation in left and right superior temporal-inferior parietal regions had better language function than those with either predominantly left- or right-sided unilateral activation. The advantage conferred by left inferior frontal and bilateral temporal involvement demonstrated in our study supports a strong predisposition for typical neural language organization, despite an intervening injury, and argues against models suggesting that the right hemisphere fully accommodates language function following early injury.