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。丰富的脑脊液（CSF）和脑血流（CBF）循环系统的病理生理信息嵌入在ICP波形动力学。然而，在目前的临床实践中，对ICP测量的解释通常只考虑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定量生物标志物的有效性。了解脑血管状态，包括血管收缩、血管舒张和整体血管舒缩活动，对脑血管疾病和脑损伤患者的治疗和管理很重要。然而，由于技术限制和伦理考虑，以连续的方式直接进入脑血管系统目前受到阻碍。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血压波在脑血管系统中传递的脉搏波速度（PWV）的一个指标。

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.