VASC MECHS OF SECONDARY INSULTS IN SEVERE BRAIN INJURY

这一建议的总体假设是，创伤性脑损伤(TBI)导致脑损伤后早期的CBF减少，这是通过两种机制造成的：1-如果CBF减少足够严重和持续足够长的时间，缺血性损伤(原发缺血；2-如果CBF减少较温和，可能不会发生缺血性损伤，但大脑更容易受到二次损伤(继发性缺血)。全球脑血流量的下降严重到足以导致缺血性损伤(脑血流量，18ml/100g/min)，发生在非常严重的损伤中，这一发现与高死亡率有关。局部脑血流减少严重到足以导致缺血性损伤(rCBF和lt；18ml/100g/min)更常见，通常见于脑挫伤和潜在的疏散的脑外血肿。更常见的是，脑血流量的适度减少可以通过增加脑氧摄取量来补偿，发生在脑损伤后的头几个小时。该项目将结合临床和实验室研究探讨创伤性脑损伤后血管变化的问题。计划项目中有3个项目和3个核心。项目1.创伤性脑损伤后脑血流的调节。项目2.创伤性脑损伤后血管阻力增加。项目3：L-精氨酸治疗颅脑损伤后脑血流量减少。核心A.管理核心B.统计和建模核心C.分析实验室核心

The overall hypothesis of this proposal is that traumatic brain injury (TBI) causes a reduction in CBF in the early post-injury period that contributes to the brain damage by 2-mechanisms: 1-if the reduction in CBF is severe enough and lasts long enough, ischemic injury (primary ischemia; occurs 2- if the reduction is CBF is more modest, ischemic injury may not occur, but the brain is more susceptible to secondary insults (secondary ischemia). Global reductions in CBF severe enough to result in ischemic injury (CBF,18 ml/100g/min) occur with very severe injuries and this finding is associated with a high mortality rate. Regional reductions in CBF severe enough to result in ischemic injury (rCBF<18 ml/100g/min) occur more commonly and are typically found in areas of brain contusion and underlying evacuated extracerebral hematomas. Even more commonly, a moderate reduction in CBF which is compensated by increased cerebral oxygen extraction occurs during the first few hours after TBI. This program projects will approach the problem of vascular changes after traumatic brain injury with both clinical and laboratory studies. There are 3 projects and 3 cores in the program project. Project 1. Regulation of Cerebral Blood Flow after Traumatic Brain Injury. Project 2. Increased Vascular Resistance after Traumatic Brain Injury. Project 3. L-arginine Treatment of a Reduced CBF after Traumatic Brain Injury. Core A. Administrative Core Core B. Statistical and Modeling Core Core C. Analytical Lab Core