VASC MECHS OF SECONDARY INSULTS IN SEVERE BRAIN INJURY

该建议的总体假设是，创伤性脑损伤（TBI）在损伤后早期引起脑血流减少，并通过两种机制导致脑损伤：1-如果脑血流减少足够严重且持续时间足够长，则发生缺血性损伤（原发性缺血）；2-如果脑血流减少较温和，则可能不会发生缺血性损伤，但大脑更容易发生继发性损伤（继发性缺血）。严重到足以导致缺血性损伤（CBF,18 ml/100g/min）的CBF全球减少发生在非常严重的损伤中，这一发现与高死亡率有关。区域性脑血流减少严重到足以导致缺血性损伤（rCBF< 18ml /100g/min）更为常见，通常发生在脑挫伤和潜在的空出性脑外血肿区域。更常见的是，在TBI后的最初几个小时内，CBF的适度减少被脑氧提取的增加所补偿。本项目将通过临床和实验室研究来探讨创伤性脑损伤后血管变化的问题。本项目有3个项目，3个核心。项目1。外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 -精氨酸治疗创伤性脑损伤后脑血流减少。核心A.行政核心B.统计与建模核心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