Tseng Ming-Yuan, Czosnyka Marek, Richards Hugh, Pickard John D, Kirkpatrick Peter J
Department of Neurosurgery, Addenbrooke's Hospital, University of Cambridge, United Kingdom.
Neurosurg Focus. 2006 Sep 15;21(3):E10. doi: 10.3171/foc.2006.21.3.10.
The authors previously have demonstrated that acute treatment with pravastatin after aneurysmal subarachnoid hemorrhage (SAH) can ameliorate vasospasm-related delayed ischemic neurological deficits (DINDs). In the current study, they test the hypothesis that these effects are associated with improvement in indices describing autoregulation of cerebral blood flow.
In this double-blind study, 80 patients between the ages of 18 and 84 years who had aneurysmal SAH were randomized equally to receive either 40 mg of oral pravastatin or placebo once daily for up to 14 days (medication was started 1.8 x 1.3 days after ictus). Autoregulation was measured using a daily transient hyperemic response test (THRT) on transcranial Doppler ultrasonography (800 measurements in 80 patients), and data were compared between the pravastatin and placebo groups and between patients with or without vasospasm, DINDs, or unfavorable outcome. Measurement of autoregulation also was performed using the pressure-reactivity index, a moving correlation coefficient between mean arterial and intracranial pressures (Days 0-5, 132 measurements in 32 patients). There was no difference in baseline autoregulation indices between the trial groups. The members of the pravastatin group not only had a shorter duration of impaired autoregulation but also had stronger transient hyperemic response ratios (THRRs) bilaterally. A negative correlation existed between the mean flow velocity in the middle cerebral artery and THRRs. Onset of DINDs occurred when bilateral autoregulation failed. On Days 3, 4, and 5, the pressure-reactivity index correlated significantly with ipsilateral impaired autoregulation.
The neuroprotective effects of acute treatment with pravastatin following aneurysmal SAH are associated with enhancement of autoregulation. A routine and daily assessment of cerebral autoregulation by using the THRT may help identify patients at high risk of DINDs.
作者之前已经证明，动脉瘤性蛛网膜下腔出血（SAH）后急性使用普伐他汀治疗可改善血管痉挛相关的迟发性缺血性神经功能缺损（DINDs）。在当前研究中，他们检验了这样一种假设，即这些效应与描述脑血流自动调节的指标改善有关。
在这项双盲研究中，80例年龄在18至84岁之间的动脉瘤性SAH患者被平均随机分为两组，一组每天口服40 mg普伐他汀，另一组服用安慰剂，持续14天（发病后1.8×1.3天开始用药）。使用经颅多普勒超声的每日短暂充血反应试验（THRT）测量自动调节功能（80例患者进行了800次测量），并在普伐他汀组和安慰剂组之间以及有或无血管痉挛、DINDs或不良预后的患者之间比较数据。还使用压力反应指数（平均动脉压与颅内压之间的移动相关系数）测量自动调节功能（第0至5天，32例患者进行了132次测量）。试验组之间的基线自动调节指标没有差异。普伐他汀组的患者不仅自动调节受损的持续时间较短，而且双侧的短暂充血反应率（THRRs）更强。大脑中动脉的平均流速与THRRs之间存在负相关。当双侧自动调节功能失败时，DINDs开始出现。在第3、4和5天，压力反应指数与同侧自动调节功能受损显著相关。
动脉瘤性SAH后急性使用普伐他汀治疗的神经保护作用与自动调节功能增强有关。通过使用THRT对脑自动调节功能进行常规每日评估可能有助于识别有DINDs高风险的患者。
