Language and cognition after perinatal stroke

项目总结 长期以来，人们一直认为，大脑在早期发育过程中最具可塑性，在脑损伤后， 儿童将皮质功能重组到健康的区域，但对这些过程知之甚少。 许多研究人员已经证明，当左半球(L H)受损时，语言可以被削弱 右半球(RH)。在这里，我们要问的是，语言功能是如何组织起来的 以及这种非典型组织对语言能力的支持程度。我们还调查了 关于RH损伤后这些功能是如何组织的补充问题。 我们将研究缺血性围产期卒中(IPS)后的长期结果，因为它相对干净 用于科学分析的属性。每4000名新生儿中就有1人发生iPS，是已知的脑性瘫痪的主要原因。 许多患有黄体生成素的围产期中风儿童的语言和认知能力发展接近正常，但 数字显示了后来的语言和认知障碍。大多数文献表明，在早期黄体生成素中风后， 语言“重组”到同伦的RH区域。我们的试点数据表明，在这种情况下， 典型的LH和RH语言功能以新的方式划分RH皮质区域。我们假设 当不同的语言功能找到不同的RH本地化时，这些功能发展得最好；重叠 语言功能会导致更多的表现受损。我们将通过调查来检验这一假设 黄体生成素围产期损伤后的语言。我们也会在RH围产期损伤后问同样的问题。 我们将招募30名患有黄体生成素围产期中风的青少年和年轻人。 30名有类似RH围产期中风的人与30名健康对照组进行比较 在年龄和社会地位上是匹配的。虽然IPS很少见，但我们的研究团队是成功招聘的理想选择。我们有 开发了我们的任务，并测试了16名围产期中风的儿童。我们将管理一系列行为 以及神经心理测试和5项功能磁共振任务。两个fMRI任务(检查命名和句子处理) 测试语言功能，激活健康对照组的黄体生成素语言区。两项功能磁共振任务(检查发声 情绪和语调)测试功能通常由RH控制。这些任务一起检查如何 语言能力在单侧大脑半球发育时会受到影响。另一项fMRI任务检查 特定对象识别(单词识别，通常在LHVWFA中，以及人脸识别，通常在RH中 FFA)询问当他们典型的神经基础完好无损但语言发生变化时，这些功能是否会发生变化。 我们的行为测试评估了当神经组织是非典型的时候，所有这些技能的运作情况。 这些研究将有助于我们理解早期大脑可塑性的灵活性和局限性。 在未来，我们的发现还有助于为开发技术来最大限度地刺激 早期脑损伤后成功的功能性组织类型。

PROJECT SUMMARY It has long been argued that the brain is most plastic during early development and that after brain injury, children reorganize cortical functions to healthy areas; but there is little understanding of these processes. Many investigators have shown that, when the left hemisphere (LH) is damaged, language can be subserved by the right hemisphere (RH). Here we ask how the linguistic functions of LH and RH are organized after LH injury and how well this atypical organization supports linguistic abilities. We also investigate the complementary questions regarding how these functions are organized after RH injury. We will study the long-term outcomes after ischemic perinatal stroke (IPS), due to its relatively clean properties for scientific analysis. IPS occurs in 1/4000 births and is the leading known cause of cerebral palsy. Many children with LH perinatal stroke develop near-normal language and cognitive abilities, but a substantial number show later language and cognitive impairments. Most literature shows that, after early LH stroke, language `reorganizes' to homotopic RH areas. Our pilot data suggest that, under these circumstances, typical LH and RH language functions divide up the RH cortical territory in new ways. We hypothesize that these functions develop best when different language functions find distinct RH localizations; overlap of linguistic functions will lead to more impaired performance. We will test this hypothesis by investigating language after LH perinatal injuries. We will also ask the same questions after RH perinatal injuries. We will recruit 30 teenagers and young adults who have had a LH perinatal stroke involving the middle cerebral artery and 30 who have had a similar RH perinatal stroke, compared with 30 healthy controls matched in age and SES. While IPS is rare, our research team is ideal for successful recruiting. We have developed our tasks and tested 16 children with perinatal strokes. We will administer a battery of behavioral and neuropsychological tests and 5 fMRI tasks. Two fMRI tasks (examining naming and sentence processing) test language functions that activate LH language areas in healthy controls. Two fMRI tasks (examining vocal emotion and intonation) test functions ordinarily controlled by the RH. Together these tasks examine how language abilities are affected when they develop in one hemisphere. An additional fMRI task examines specific object recognition (word recognition, ordinarily in LH VWFA, and face recognition, ordinarily in RH FFA) to ask if these functions are altered when their typical neural substrates are intact but language is shifted. Our behavioral tests assess how well all of these skills operate when neural organization is atypical. These studies will contribute to our understanding of the flexibility and limitations of early brain plasticity. In the future our findings can also help to provide a foundation for developing techniques to stimulate the most successful types of functional organization after early brain injuries.