School of Medicine, University of New Mexico (B.O.).
Department of Internal Medicine, University of Arizona College of Medicine (A.V.).
Stroke. 2022 Jun;53(6):1975-1983. doi: 10.1161/STROKEAHA.121.037184. Epub 2022 Feb 24.
Delayed cerebral ischemia remains one of the principal therapeutic targets after aneurysmal subarachnoid hemorrhage. While large vessel vasospasm may contribute to ischemia, increasing evidence suggests that physiological impairment through disrupted impaired cerebral autoregulation (CA) and spreading depolarizations (SDs) also contribute to delayed cerebral ischemia and poor neurological outcome. This study seeks to explore the intermeasure correlation of different measures of CA, as well as correlation with SD and neurological outcome.
Simultaneous measurement of 7 continuous indices of CA was calculated in 19 subjects entered in a prospective study of SD in aneurysmal subarachnoid hemorrhage undergoing surgical aneurysm clipping. Intermeasure agreement was assessed, and the association of each index with modified Rankin Scale score at 90 days and occurrence of SD was assessed.
There were 4102 hours of total monitoring time across the 19 subjects. In time-resolved assessment, no CA measures demonstrated significant correlation; however, most demonstrate significant correlation averaged over 1 hour. Pressure reactivity (PRx), oxygen reactivity, and oxygen saturation reactivity were significantly correlated with modified Rankin Scale score at 90 days. PRx and oxygen reactivity also were correlated with the occurrence of SD events. Across multiple CA measure reactivity indices, a threshold between 0.3 and 0.5 was most associated with intervals containing SD.
Different continuous CA indices do not correlate well with each other on a highly time-resolved basis, so should not be viewed as interchangeable. PRx and oxygen reactivity are the most reliable indices in identifying risk of worse outcome in patients with aneurysmal subarachnoid hemorrhage undergoing surgical treatment. SD occurrence is correlated with impaired CA across multiple CA measurement techniques and may represent the pathological mechanism of delayed cerebral ischemia in patients with impaired CA. Optimization of CA in patients with aneurysmal subarachnoid hemorrhage may lead to decreased incidence of SD and improved neurological outcomes. Future studies are needed to evaluate these hypotheses and approaches.
迟发性脑缺血仍然是蛛网膜下腔出血后主要的治疗靶点之一。虽然大血管血管痉挛可能导致缺血，但越来越多的证据表明，通过破坏受损的脑自动调节（CA）和传播性去极化（SD）导致的生理障碍也会导致迟发性脑缺血和不良神经结局。本研究旨在探讨 CA 的不同测量方法之间的相互关系，以及与 SD 和神经结局的相关性。
对 19 例接受手术夹闭动脉瘤的蛛网膜下腔出血患者进行前瞻性 SD 研究，同时计算了 CA 的 7 个连续指标。评估了测量间的一致性，并评估了每个指标与 90 天改良 Rankin 量表评分和 SD 发生的相关性。
19 例患者共监测了 4102 小时。在时间分辨评估中，没有 CA 指标显示出显著相关性；然而，大多数指标在 1 小时内的平均水平上显示出显著相关性。压力反应性（PRx）、氧反应性和氧饱和度反应性与 90 天改良 Rankin 量表评分显著相关。PRx 和氧反应性也与 SD 事件的发生相关。在多个 CA 测量反应性指标中，0.3 到 0.5 之间的阈值与包含 SD 的间隔最相关。
不同的连续 CA 指标在高度时间分辨的基础上彼此相关性不好，因此不应视为可互换的。PRx 和氧反应性是识别接受手术治疗的蛛网膜下腔出血患者预后不良风险的最可靠指标。SD 的发生与多种 CA 测量技术的 CA 受损相关，可能代表了 CA 受损患者迟发性脑缺血的病理机制。优化蛛网膜下腔出血患者的 CA 可能会降低 SD 的发生率和改善神经结局。需要进一步研究来评估这些假设和方法。
