Neural and Cognitive Sequelae of Blast-Induced Traumatic Brain Injury

描述(由申请人提供)： 摘要：颅脑损伤是伊拉克战争中最常见的损伤，随着简易爆炸装置的使用越来越多，与战争有关的脑损伤大多是闭合性爆炸伤。BTBI患者中与应激相关的精神疾病(尤其是创伤后应激障碍和抑郁)的高发生率为诊断提出了独特的挑战。轻度脑外伤和应激相关的精神症状导致相似的临床表现以及相似的认知神经心理损害。重叠的神经学和精神病学状况对神经心理和功能结果的影响尚不清楚，更好地了解它们各自的贡献和相互作用对于为遭受冲击伤的患者制定最佳干预策略至关重要。弥散张量成像(DTI)是一种测量白质功能完整性的神经成像技术，已被证明对轻度非冲击性脑损伤后的细微变化特别敏感。在这里，我们使用DTI作为一种量化冲击波暴露引起的神经损伤的手段，并评估其在区分轻度bTBI和精神共病对冲击伤军事人员认知和功能障碍星座的贡献方面的有效性。拟议研究的具体目标有四个方面。首先，这项研究的目的是描述与轻度脑外伤相关的白质异常，无论是来自一次冲击伤还是二次/三级损伤，并评估是否存在弥散异常是脑外伤而不是精神症状的唯一诊断标志的区域。其次，本研究旨在评价观察到的脑白质微结构异常的功能意义。我们假设，在注意力/执行功能、记忆和精神运动速度领域的表现将与脑外伤相关的扩散异常有关，认知表现和这些白质异常之间的关系将被精神疾病的存在所缓和。第三，这项研究旨在揭示bTBI后认知功能和生活质量的最佳预测因素，考虑到bTBI相关的扩散异常和精神共病的贡献可能随着爆炸负荷和其他损伤相关变量的不同而不同。最后，这项研究的目的是检查扩散异常和精神疾病共病与长期认知和功能结果的关系，在9个月的随访中进行评估。这项研究不仅有可能为bTBI相关的神经变化提供一个敏感的诊断标记物，而且还可以极大地提高我们对神经和精神异常在与冲击伤相关的认知和功能损害中的作用的理解。

DESCRIPTION (provided by applicant): Abstract: Traumatic brain injury (TBI) is the most common injury of the Iraq war, and with the increased use of improvised explosive devices, a majority of war-related brain injuries are closed head injuries that result from blast. The high incidence of stress-related psychiatric co-morbidities (in particular, PTSD and depression) in individuals with bTBI raises unique challenges for diagnosis. Mild TBI and stress-related psychiatric symptoms lead to similar clinical presentations as well as to similar cognitive neuropsychological impairments. The impact of overlapping neurologic and psychiatric conditions on neuropsychological and functional outcome remains unclear and a better understanding of their individual contributions and interactions is critical to the development of optimal intervention strategies for patients who suffered blast injury. Diffusion tensor imaging (DTI), a neuroimaging technique that measures the functional integrity of white matter, has proven to be especially sensitive to the subtle changes following mild non-blast TBI. Here we use DTI as a means of quantifying neural injury resulting from blast exposure and evaluate its utility in disentangling the contribution of mild bTBI and psychiatric co-morbidities to the constellation of cognitive and functional deficits seen in military personnel with blast injury. The specific goals of the proposed research are four-fold. First, this study aims to characterize the white matter abnormalities associated with mild bTBI, whether from primary blast or secondary/tertiary injury, and to evaluate whether there are regions in which diffusion abnormalities are unique diagnostic markers of TBI, and not of psychiatric symptoms. Second, this study aims to evaluate the functional significance of the observed microstructural white matter abnormalities. We hypothesize that performance in the domains of attention/executive function, memory, and psychomotor speed will be related to TBI-associated diffusion abnormalities, and that the relationship between cognitive performance and these white matter abnormalities will be moderated by the presence of psychiatric co-morbidities. Third, the study aims to uncover optimal predictors of cognitive functioning and quality of life following bTBI, taking into account that the contribution of bTBI-associated diffusion abnormalities and psychiatric co-morbidities may differ as a function of blast load and other injury-related variables. Finally, the study aims to examine how diffusion abnormalities and psychiatric co-morbidities are related to long-term cognitive and functional outcome, assessed at 9-month follow-up. This research has the potential not only to provide a sensitive diagnostic marker for neural changes associated with bTBI, but also to greatly enhance our understanding of the contributions of neural and psychiatric abnormalities to the cognitive and functional impairments associated with blast injury.