Intracranial Pressure Latency as a Biomarker of Cerebral Vasculature Status

描述（由申请人提供）：颅内压（ICP）是各种神经/神经外科疾病患者广泛监测的生理信号。颅内压波形动力学包含了丰富的脑脊液（CSF）和脑血流（CBF）循环系统的病理生理学信息。然而，在目前的临床实践中，ICP测量的解释，在很大程度上，只考虑ICP的绝对值。我们的总体目标是开发一种临床友好的信号处理方法，用于从ICP波形中提取新的潜伏期测量，并证明其作为脑血管系统状态的定量生物标志物的有效性。了解脑血管系统状态（包括血管收缩、血管舒张和总体血管活性）对于治疗和管理脑血管疾病和脑损伤患者非常重要。然而，以连续的方式直接进入脑血管系统目前受到技术限制和伦理考虑的阻碍。我们的中心假设是ICP脉冲相对于颅外循环定时信号的潜伏期是脑血管系统中血压波传输的脉搏波速度（PWV）的指标。 我们提出了两个目的，研究两个ICP潜伏期措施，包括启动和P1潜伏期响应两个实验干预：CO2挑战和姿势变化的行为。所提出的实验程序将有助于确定使用ICP潜伏期指标指示脑血管变化的真阳性和假阳性方面。 如果得到验证，ICP潜伏期测量可用于连续监测脑血管系统变化，这些变化可能存在于脑血管痉挛的发展中，用于表征脑血管床的储备，并用于量化脑血流自动调节的效率。 公共卫生相关性本项目的目的是开发和验证一种新的ICP潜伏期测量方法，作为脑血管变化的替代。ICP潜伏期测量可用于连续监测脑血管系统的变化，可能存在于脑血管痉挛的发展，在表征储备的脑血管床，并量化脑血流自动调节的效率。

DESCRIPTION (provided by applicant): Intracranial pressure (ICP) is a widely monitored physiological signal for patients with various neurological / neurosurgical diseases. A wealth of pathophysiological information of cerebrospinal fluid (CSF) and cerebral blood flow (CBF) circulatory systems is embedded in ICP waveform dynamics. Nevertheless, interpretation of ICP measurement in current clinical practice, in large, considers only absolute value of ICP. Our overall goal is to develop a clinically friendly signal processing method for extracting a novel latency measure from ICP waveform and demonstrate its effectiveness as a quantitative biomarker of status of cerebral vasculature. Knowledge of cerebral vasculature status including vasoconstriction, vasodilatation, and overall vasomotor activity is important in treating and managing patients with cerebral vascular disorders and brain injury. However, direct access of cerebral vasculature in a continuous fashion is currently hindered by technical limits and by ethic considerations. Our central hypothesis is that latency of an ICP pulse relative to an extracranial circulatory timing signal is an indicator of pulse wave velocity (PWV) of blood pressure wave transmission in the cerebral vasculature. We propose two aims to study the behavioral of two ICP latency measures including the onset and the P1 latency in response to two experiment interventions: CO2 challenge and postural changes. The proposed experiment procedures will help determine the true positive and false positive aspect of using ICP latency measures for indicating cerebrovascular changes. If validated, the ICP latency measure could be useful in continuously monitoring cerebral vasculature changes that could be present in the development of cerebral vasospasm, in characterizing the reserve of cerebral vascular bed, and in quantifying the efficiency of cerebral blood flow autoregulation. PUBLIC HEALTH RELEVANCE The objectives of this project are to develop and validate a novel ICP latency measure as a surrogate of cerebrovascular changes. The ICP latency measure could be useful in continuously monitoring cerebral vasculature changes that could be present in the development of cerebral vasospasm, in characterizing the reserve of cerebral vascular bed, and in quantifying the efficiency of cerebral blood flow autoregulation.