Brain fluid clearance and misfolded protein dynamics following traumatic brain injury

项目摘要/摘要 创伤性脑损伤是导致死亡和残疾的主要原因，也是以后发生脑损伤的危险因素。 阿尔茨海默病(AD)本项目的重点是脑、脑脊髓/间质液体系统 清除大脑中的废物和毒素，包括淋巴系统，对脑血管疾病的病理生理学很重要。 TBI和AD都是。我们将使用神经成像来测量脑外伤后脑液的清除情况。我们的预赛 结果表明，TBI导致清扫率显著降低。在这个项目中，我们将证实这些结果 使用其他清除测量方法，并确定是否与较低的损伤后清除相关 脑外伤后认知、功能和症状恢复较差。 我们还将使用神经成像(正电子发射断层扫描)来测量大脑淀粉样蛋白-β(Aβ)-a 颅脑损伤后应尽早标记AD的病理特征。对动物的研究和我们的初步数据 在人类中表明，Aβ在脑损伤后释放并迅速沉积在大脑中，但在一段可变的时间段后 时间，通常不再存在。我们假设脑液清除率可以预测这种变化。 颅脑损伤后一年以上的A脑β。较差的通过率和持续性的β可能(部分)解释了为什么脑外伤是一种风险 AD的因素。此外，在TBI之后监控这些流程将提供与以下内容相关的信息 大体上了解AD，因为同样的病理生理-清除不良导致β沉积- 发生在公元后，但在几十年内缓慢，使其更难研究。 我们将进行一项为期五年的纵向研究，在中等或中等水平后的几小时内招募受试者 复杂-来自繁忙的纽约市急诊室网络的轻微TBI。神经成像，脑外伤抽血 生物标志物和详细的认知/临床评估将在14天后尽快进行 损伤后1年复查。因为目前还没有测量脑液清除量的黄金标准 在人类身上，我们使用一组互补的PET和MRI神经成像方法来估计液体流量， 通过大脑中相互连接的充满液体的空间进行混合和清除。这包括我们的PET方法 开发了一种测量放射性示踪剂从脑室流出的速率的仪器。将这些措施整合起来 多模式方法将比使用任何方法更深入地了解人体体液的清除情况 单一模式，还将提供有关每项测量的相对准确性/预测能力的信息 这可以为设计人员提供未来研究的信息。 该项目的结果将提供有关脑外伤后脑液清除的新信息，这也是相关的 到AD，这可以为靶向治疗提供信息，以促进TBI的恢复并降低未来的风险 神经退行性变。

PROJECT SUMMARY/ABSTRACT Traumatic Brain Injury (TBI) is a leading cause of death and disability and a risk factor for later development of Alzheimer's Disease (AD.) This project focuses on brain cerebrospinal/interstitial fluid systems essential for clearing the brain of waste and toxins, including the glymphatic system, as important to the pathophysiology of both TBI and AD. We will use neuroimaging to measure brain fluid clearance after TBI. Our preliminary results suggest that TBI causes significant reduction in clearance. In this project, we will confirm these results using additional clearance measurement methods, and determine if lower post-injury clearance is associated with worse cognitive, functional and symptomatic recovery from TBI. We will also use neuroimaging (Positron Emission Tomography - PET) to measure brain amyloid-β (Aβ) – a hallmark pathologic feature of AD – as soon as possible after TBI. Studies in animals and our preliminary data in humans indicate that Aβ is released after TBI and deposits rapidly in the brain, but after a variable period of time, is usually no longer present. We hypothesize that the rate of brain fluid clearance will predict the change in brain Aβ over one year after TBI. Poor clearance and persistent Aβ may explain (in part) why TBI is a risk factor for AD. In addition, monitoring these processes after TBI will provide information relevant to understanding AD in general, since this same pathophysiology – poor clearance leading to Aβ deposition – occurs in AD, but slowly over decades, making it more difficult to study. We will conduct a five year longitudinal study which will recruit subjects within hours after moderate or complex-mild TBI from a network of busy NYC emergency rooms. Neuroimaging, blood draw for TBI biomarkers and detailed cognitive/clinical assessment will be performed as soon as possible (<14 days) after injury and repeated at one year. Because there is no current gold standard for measuring brain fluid clearance in humans, we use a panel of complementary PET and MRI neuroimaging methods to estimate fluid flow, mixing and clearance through interconnected fluid-filled spaces in the brain. This includes a PET method we developed that measures the rate of radiotracer egress from the ventricle. Integrating measures from these multimodal methods will provide greater insight into human fluid clearance than could be achieved with any single modality, and will also provide information about the relative accuracy/predictive ability of each measure that can inform design of future studies. Results from this project will provide novel information about brain fluid clearance after TBI that is also relevant to AD, and that can inform targeted therapies to enhance TBI recovery and reduce future risk of neurodegeneration.