Neurometabolism and Outcome in Traumatic Brain Injury

创伤性脑损伤（TBI）是造成年轻健康人群死亡和发病的主要原因，并造成巨大的社会和经济代价。尽管在大型研究中，常用的临床标志物在统计上与总体功能相关，但它们在预测个体患者的认知功能方面用处不大。同样，尽管传统的神经影像学研究可以指导急性临床管理，但结果预测是不可靠的，特别是在损伤消退的早期阶段。我们实验室的初步数据表明，通过非侵入性磁共振波谱测量的脑细胞损伤的神经代谢物标志物与认知功能和结果密切相关。此外，我们的数据显示，某些解剖部位比其他部位损伤更严重（即，大脑前侧比后侧更严重），灰质神经代谢物比白质更可靠地预测认知结果，表明组织对TBI的反应存在异质性。我们还表明，这些神经代谢物的恢复暂时与认知改善有关。我们提出了一种评估和研究TBI的新方法，使用定量磁共振光谱成像（SI）和MRI来量化细胞脑损伤。这些N-乙酰天冬氨酸、含胆碱化合物和水松弛时间的测量是预测大脑功能和结果的有力新工具。利用这些正常表现（通过MRI）大脑损伤的神经代谢物标记物，我们旨在确定特定模式-解剖和/或组织类型的损伤是否与特定形式的认知功能障碍相关。磁共振波谱成像为研究脑损伤后神经元的代谢完整性提供了一个强大的新工具，并可能为临床管理、患者异质性、结果预测和治疗方案有效性的确定提供新的见解。

Traumatic brain injury (TBI) is the leading cause of death and morbidity in young, otherwise healthy populations and results in an enormous social and economic cost. Although commonly used clinical markers are statistically linked with gross functioning in large studies, they are less useful in predicting cognitive functioning in individual patients. Similarly, although conventional neuroimaging studies can guide acute clinical management, outcome prediction is unreliable, particularly at early stages of injury resolution. Preliminary data from our laboratory show that neurometabolite markers of brain cellular injury measured by non-invasive magnetic resonance spectroscopy are strongly correlated with cognitive function and outcome. Further, our data show that certain anatomic locations are more intensely injured than others (i.e., anterior brain more than posterior), and that gray matter neurometabolites predict cognitive outcome more reliably than white matter, suggesting tissue heterogeneity of response to TBI. We also show that recovery of these neurometabolites is temporarily associated with cognitive improvement. We propose a novel approach for assessment and study of TBI using quantitative magnetic resonance spectroscopic imaging (SI) and MRI to quantify cellular brain injury. These measurements of N- acetylaspartate, choline-containing compounds, and water relaxation times are a powerful new tool for prediction of brain function and outcome. Using these neurometabolite markers of injury in normal-appearing (by MRI) brain, we aim to determine whether specific patterns-anatomic and/or tissue-type of injury are associated with specific forms of cognitive dysfunction. Magnetic resonance spectroscopic imaging offers a robust new tool to investigate the metabolic integrity of the neuron following TBI, and may provide new insight into clinical management, patient heterogeneity, prediction of outcome, and the determination of effectiveness of therapeutic options.