NEUROBEHAVIORAL OUTCOME OF PEDIATRIC HEAD INJURY

本项目旨在评估创伤性脑损伤（TBI）儿童在认知、行为和运动等多个领域的神经行为结果。该假说认为，额叶损伤的性质和程度在年龄和损伤严重程度之外的结果中具有显著的可变性。基于MRI的发现，局灶性脑损伤与认知后遗症的关系，特别是执行功能，被调查。在美国，创伤性脑损伤是儿童最常见的死亡原因（病死率从3 /100到14/100不等）和获得性脑损伤（180/100,000住院病例的发生率），也是造成发育障碍的主要原因。据估计，美国每年有17000名儿童因头部受伤而残疾，原因包括解决问题和计划等执行功能缺陷，以及记忆、注意力、阅读、算术、运动、精神和适应性行为领域的障碍。尽管大多数严重闭合性脑损伤（CHI）患者在智力和语言功能的传统测试中恢复到正常范围，但我们发现EF缺陷在解决问题、计划、反应调节和口头和书面叙述的产生方面仍然存在。发展认知理论家认为，ef是(1)对未来目标的问题解决能力的维护；(2)行为随时间的组织；(3)有序处理问题；(4)策略运用熟练；(5)灵活有效的言语自我调节；(6)改变儿童后续反应可能性的反应或行动（即对反馈的反应）；并假设脑电图依赖于前额叶区域的成熟和完整。我们研究了EF缺陷与CHI病理生理之间的关系，发现61%的严重CHI患儿有前额叶病变。工作记忆和抑制（定义如下）是基本的、互动的过程，涉及到更复杂的技能，如解决问题、推理、计划、阅读和听觉理解、算术和自我调节，而元认知技能是综合能力，使儿童能够评估他们的知识、监控他们的认知活动和部署策略。我们假设这些功能的完整性对言语处理、学业成就和适应性行为的发展至关重要，而抑制和元认知技能与儿童CHI的精神结局有关。目的1探讨了包括工作记忆、抑制和元认知技能在内的特定EF缺陷与CHI急性严重程度、局灶性脑病变成像和年龄差异的关系。目的2和3代表了一个新的方向，即研究工作记忆、抑制和元认知技能完整性的变异性如何与CHI儿童的话语、学业成就、适应行为和精神结局相关。因此，该项目将认知结构与脑成像和结果领域结合起来，其中包括发育神经精神病学，目的是改善对脑损伤儿童的评估和干预。

The goals of this project are to evaluate neurobehavioral outcomes in multiple domains: cognitive, behavioral, and motoric, for children who sustain traumatic brain injury (TBI). The hypothesis is that the nature and extent of injury to the frontal lobes account for significant variability in outcome beyond age and injury severity. Based on MRI findings, the relationship of focal brain lesions to cognitive sequelae, particularly executive functions, are investigated. Traumatic brain injury is the most common cause of death (case fatality rate ranging from 3 to 14/100 cases) and acquired brain insult (incidence of 180/100,000 hospitalized cases) in children in the U.S. and a major contributor to developmental disability. An estimated 17,000 children are disabled by head injury each year in the U.S. due to deficient executive functions (EFs) such as problem solving and planning as well as impairments in memory, attention, reading, arithmetic, motor, psychiatric, and adaptive behavior domains. Despite recovery of most severe closed head injury (CHI) patients to the normal range on traditional tests of intellectual and language functions, we have found that EF deficits persist on measures of problem solving, planning, response modulation, and production of oral and written narratives. Developmental cognitive theorists view EFs as (1) maintenance of a problem solving set for future goals; (2) organization of behavior over time; (3) orderly approaches to problems; (4) skillful use of strategies; (5) flexible and effective verbal self-regulation; (6) responses or actions that function to alter the probability of a subsequent response of the child (i.e., responsiveness to feedback); and postulate that EFs depend on the maturation and integrity of the prefrontal region. We have examined the relationship between EF deficits and the pathophysiology of CHI and identified that 61% of children with severe CHI had prefrontal lesions. Working memory and inhibition (defined below) are fundamental, interactive processes involved in more complex skills such as problem solving, inferencing, planning, reading and aural comprehension, arithmetic, and self-regulation, whereas metacognitive skills are integrative abilities enabling children to assess their knowledge, monitor their cognitive activities, and deploy strategies. We hypothesize that the integrity of these components of EFs is crucial to the development of discourse processing, academic achievement, and adaptive behavior while inhibition and metacognitive skills are related to the psychiatric outcome of CHI in children. Aim 1 addresses the relationship of specific EF deficits involving working memory, inhibition, and metacognitive skills to the acute severity of CHI, imaging of focal brain lesions, and age differences. Aims 2 and 3 represent a new direction which investigates how variability in the integrity of working memory, inhibition, and metacognitive skills is related to discourse, academic achievement, adaptive behavior, and psychiatric outcomes of CHI in children. This project thus integrates cognitive constructs with brain imaging and outcome domains which include developmental neuropsychiatry with the goal of improving assessment and interventions for brain injured children.