Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada.
Department of Biomedical Engineering, University of Manitoba, Winnipeg, Canada.
J Neurotrauma. 2023 Jun;40(11-12):1098-1111. doi: 10.1089/neu.2022.0293. Epub 2022 Oct 21.
Impaired cerebrovascular reactivity has emerged as an important associate with poor long-term outcome after moderate/severe traumatic brain injury (TBI). However, our understanding of what drives or modulates the degree of impaired cerebrovascular function remains poor. Age and biological sex remain important modifiers of cerebrovascular function in health and disease, yet their impact on cerebrovascular reactivity after TBI remains unclear. The aim of this study was to explore subgroup responses based on age and biological sex on cerebral physiology. Data from 283 TBI patients from the CAnadian High Resolution TBI (CAHR-TBI) Research Collaborative were evaluated. Cerebrovascular reactivity was determined using high-frequency cerebral physiology for the derivation of three intracranial pressure (ICP)-based indices: 1) pressure reactivity index (PRx)-correlation between ICP and mean arterial pressure (MAP); 2) pulse amplitude index (PAx)-correlation between pulse amplitude of ICP (AMP) and MAP; and 3) RAC-correlation between AMP and cerebral perfusion pressure (CPP). Insult burden (% time above clinically defined thresholds) were calculated for these indices. These cerebral physiology indices were studied for their relationship with age via linear regression, age trichotomization (< 40, 40 - 60, > 60), and decades of age (< 30, 30-39, 40-49, 50-59, 60-69, > 69) schemes. Similarly, differences based on biological sex were assessed. A statistically significant positive linear correlation was found between PAx, RAC, and age. In corollary, a statistically significant relationship was found between increasing age on trichotomized and decades of age analysis with PAx and RAC measures. PRx failed to demonstrate such relationships to advancing age. There was no clear difference in cerebrovascular reactivity profiles between biological sex categories. These findings suggest that AMP-based cerebrovascular reactivity indices may be better positioned to detect impairment in TBI patients with advancing age. Further investigation into the utility of PAx and RAC is required, as they may prove useful for certain subgroups of patients.
脑血流反应性受损已成为中重度创伤性脑损伤（TBI）后预后不良的一个重要因素。然而，我们对导致或调节脑血管功能受损程度的因素仍知之甚少。年龄和生物学性别仍然是健康和疾病中脑血管功能的重要调节剂，但它们对 TBI 后脑血管反应性的影响尚不清楚。本研究旨在探讨基于年龄和生物学性别的亚组对脑生理的反应。评估了来自加拿大高分辨率 TBI（CAHR-TBI）研究协作组的 283 名 TBI 患者的数据。使用高频脑生理学来确定三个基于颅内压（ICP）的指数来评估脑血管反应性：1）压力反应性指数（PRx）-ICP 与平均动脉压（MAP）之间的相关性；2）脉搏幅度指数（PAx）-ICP 脉搏幅度（AMP）与 MAP 之间的相关性；3）RAC-AMP 与脑灌注压（CPP）之间的相关性。计算了这些指数的损伤负担（%时间超过临床定义的阈值）。通过线性回归、年龄三分位数（<40、40-60、>60）和年龄十年（<30、30-39、40-49、50-59、60-69、>69）方案研究了这些脑生理指数与年龄的关系。同样，也评估了基于生物学性别的差异。发现 PAx、RAC 与年龄之间存在显著的正线性相关。相应地，在三分位数和十年分析中，年龄增加与 PAx 和 RAC 测量值之间存在显著的关系。PRx 未能显示出与年龄相关的关系。在生物学性别类别之间，脑血管反应性谱没有明显差异。这些发现表明，基于 AMP 的脑血管反应性指数可能更适合检测年龄增长的 TBI 患者的损伤。需要进一步研究 PAx 和 RAC 的效用，因为它们可能对某些特定患者群体有用。
