NEUROBEHAVIORAL OUTCOME OF PEDIATRIC HEAD INJURY

点击翻译按钮获取中文摘要

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.