Lan Linfang, Leng Xinyi, Ip Vincent, Leung Thomas, Soo Yannie, Abrigo Jill, Wong Ka Sing
Department of Medicine and Therapeutics, Division of Neurology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China.
Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, 999077, China.
Curr Neurovasc Res. 2017;14(2):149-157. doi: 10.2174/1567202614666170413143203.
Intracranial arterial stenosis (ICAS) is the dominant cause for ischemic stroke worldwide, with hemodynamic compromise as a crucial contributor. Prolonged perfusion is commonly observed in ICAS patients on CT perfusion (CTP) maps, while the clinical significance of this perfusion pattern has not been elucidated.
Patients having symptomatic ICAS of 50-99% stenosis with sustained downstream cerebral blood flow (CBF) were enrolled in this study. Prolonged perfusion was defined as increased mean transit time (MTT) in vascular territories of the target ICAS on CTP maps. The primary clinical outcome was recurrence of ipsilateral ischemic stroke, and secondary outcome was any ipsilateral ischemic events at 2 years follow-up.
Of the 95 patients (median age 61y; 70% males) with symptomatic ICAS, 29 patients (30.5%) had prolonged perfusion. Such delayed perfusion was persistent in a majority of patients according to the 1-year imaging follow-up. The prolongation of cerebral perfusion was associated with subsequent risk for ipsilateral ischemic stroke (HR 7.01; 95% CI 1.86-26.46; p = 0.004), but not for any ipsilateral ischemic events (HR 1.52; 95% CI 0.63-3.68; p = 0.348). Further comparison of perfusion measures showed lower CBF (p = 0.034) and higher MTT (p = 0.064) in patients with recurrent ischemic stroke, but not in those with recurrent transient ischemic attack (TIA). Among patients with recurrent stroke, a majority had multiple infarcts along the borderzone regions.
In patients with symptomatic ICAS, persistent prolonged cerebral perfusion might contribute to the relapse of ischemic stroke, but not TIA.
颅内动脉狭窄（ICAS）是全球缺血性卒中的主要病因，血流动力学障碍是其关键因素。在CT灌注（CTP）图上，ICAS患者常出现灌注时间延长的情况，但其临床意义尚未阐明。
本研究纳入了症状性ICAS狭窄率为50%-99%且下游脑血流量（CBF）持续存在的患者。灌注时间延长定义为CTP图上目标ICAS血管区域的平均通过时间（MTT）增加。主要临床结局为同侧缺血性卒中复发，次要结局为2年随访时的任何同侧缺血事件。
在95例症状性ICAS患者（中位年龄61岁；70%为男性）中，29例（30.5%）出现灌注时间延长。根据1年影像学随访，大多数患者的这种延迟灌注持续存在。脑灌注延长与随后同侧缺血性卒中的风险相关（HR 7.01；95%CI 1.86-26.46；p = 0.004），但与任何同侧缺血事件无关（HR 1.52；95%CI 0.63-3.68；p = 0.348）。灌注指标的进一步比较显示，复发性缺血性卒中患者的CBF较低（p = 0.034），MTT较高（p = 0.064），而复发性短暂性脑缺血发作（TIA）患者则不然。在复发性卒中患者中，大多数患者在边缘区有多处梗死。
在症状性ICAS患者中，持续性脑灌注时间延长可能导致缺血性卒中复发，但不会导致TIA复发。
