Cerebral vasospasm (VS) and delayed cerebral ischemia (DCI) constitute major complications following subarachnoid hemorrhage (SAH). A few studies have examined the relationship between different indices of cerebrovascular dynamics with the occurrence of VS. However, their potential association with the development of DCI remains elusive. In this study, we investigated the pattern of changes of different transcranial Doppler (TCD)-derived indices of cerebrovascular dynamics during vasospasm in patients suffering from subarachnoid hemorrhage, dichotomized by the presence of delayed cerebral ischemia. A retrospective analysis was performed using recordings from 32 SAH patients, diagnosed with VS. Patients were divided in two groups, depending on development of DCI. Magnitude of slow waves (SWs) of cerebral blood flow velocity (CBFV) was measured. Cerebral autoregulation was estimated using the moving correlation coefficient Mxa. Cerebral arterial time constant (tau) was expressed as the product of resistance and compliance. Complexity of CBFV was estimated through measurement of sample entropy (SampEn). In the whole population (N = 32), magnitude of SWs of ipsilateral to VS side CBFV was higher during vasospasm (4.15 ± 1.55 vs before: 2.86 ± 1.21 cm/s, p < 0.001). Ipsilateral SWs of CBFV before VS had higher magnitude in DCI group (N = 19, p < 0.001) and were strongly predictive of DCI, with area under the curve (AUC) = 0.745 (p = 0.02). Vasospasm caused a non-significant shortening of ipsilateral values of tau and increase in SampEn in all patients related to pre-VS measurements, as well as an insignificant increase of Mxa in DCI related to non-DCI group (N = 13). In patients suffering from subarachnoid hemorrhage, TCD-detected VS was associated with higher ipsilateral CBFV SWs, related to pre-VS measurements. Higher CBFV SWs before VS were significantly predictive of delayed cerebral ischemia.

中文翻译：

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蛛网膜下腔出血患者经颅多普勒血流速度慢波与延迟性脑缺血的关系

脑血管痉挛（VS）和迟发性脑缺血（DCI）构成蛛网膜下腔出血（SAH）后的主要并发症。一些研究检查了脑血管动力学的不同指标与VS发生之间的关系。但是，它们与DCI的发展之间的潜在联系仍然难以捉摸。在这项研究中，我们调查了蛛网膜下腔出血患者脑血管动态变化过程中不同经颅多普勒（TCD）衍生的脑血管动力学指数的变化模式，该现象被延迟性脑缺血的存在所分割。回顾性分析使用了32例经确诊为VS的SAH患者的记录进行。根据DCI的发展，将患者分为两组。测量脑血流速度（CBFV）的慢波（SWs）的大小。使用运动相关系数Mxa估计大脑的自动调节。脑动脉时间常数（tau）表示为阻力和顺应性的乘积。CBFV的复杂性是通过测量样本熵（SampEn）来估算的。在整个人群中（N = 32），在血管痉挛期间同侧至VS侧CBFV的SW幅度更高（4.15±1.55 vs之前：2.86±1.21 cm / s，p <0.001）。VS之前，CBFV的同侧SW在DCI组中具有更高的大小（N = 19，p <0.001），并且强烈预测DCI，曲线下面积（AUC）= 0.745（p = 0.02）。血管痉挛导致与VS前测量相关的所有患者的tau同侧值无明显缩短，SampEn升高，与非DCI组相关的DCI中Mxa无明显升高（N = 13）。在患有蛛网膜下腔出血的患者中，TCD检测到的VS与同侧CBFV SW增高相关，与VS前的测量有关。VS之前较高的CBFV SW显着预测了脑缺血延迟。