颅内蛛网膜囊肿占位诱发癫痫的影像及血流动力学研究

Imaging and hemodynamic study of epilepsy induced by space-occupying intracranial arachnoid cyst

目的探讨颅内蛛网膜囊肿(intracranial arachnoid cyst,IAC)与癫痫的相关性和IAC导致癫痫的可能机制。方法纳入2009年1月-2019年1月于四川大学华西医院就诊的IAC患者,根据是否伴发癫痫分为IAC伴癫痫组和IAC不伴癫痫组。建立所有受试者MRI图像的三维空间坐标系,统计IAC位置信息;采用计算流体力学技术对受试者增强CT图像建立囊肿区域血管模型,进行血流动力学分析。结果共纳入患者72例,其中IAC伴癫痫组24例,IAC不伴癫痫组48例。两组患者性别、年龄、IAC位置、IAC体积、IAC最大径比较,差异均无统计学意义(P>0.05)。IAC伴癫痫组发现的7个高危区域点形成的连续区域位于颞区,这7个点在IAC伴癫痫组同时出现5次,在IAC不伴癫痫组同时出现1次,其差异有统计学意义(χ^(2)=5.114,P=0.024)。比较两组血管模型的血流动力学参数,发现两者的压力变化和血压参数相似,IAC伴癫痫组的血流量更低、血管平均壁切应力更大。结论IAC可通过其占位效应使得邻近血管狭窄、血管壁切应力增高,从而引起癫痫;伴发癫痫的IAC最常出现的位置是颞区,IAC伴癫痫的患者在行手术治疗前,致痫灶定位应考虑IAC的占位效应。

Objective To investigate the correlation of intracranial arachnoid cyst(IAC)with epilepsy and the possible mechanism of seizure induced by IAC.Methods Patients with IAC,who were treated in West China Hospital of Sichuan University between January 2009 and January 2019,were included and divided into IAC with epilepsy group and IAC without epilepsy group according to whether they were diagnosed with epilepsy.We collected the IAC location information of all subjects after the establishment of a three-dimensional spatial coordinate system of MRI images.Computational fluid dynamics technology was used to establish a blood vessel model in cyst area and perform hemodynamic analysis basing on contrast-enhanced CT images.Results A total of 72 patients were enrolled,including24 in the IAC with epilepsy group and 48 in the IAC without epilepsy group.There was no significant difference between the two groups in terms of sex,age,IAC location,the volumes or the maximum diameters of IAC(P>0.05).Consecutive areas formed by the seven high-risk areas found in the IAC with epilepsy group were located in the temporal area.The seven high-risk areas were simultaneous IAC location in 5 patients in the IAC with epilepsy group and in 1 patient in the IAC without epilepsy group,and the difference was statistically significant(χ^(2)=5.114,P=0.024).Comparison of the hemodynamic parameters between the two types of vascular models revealed similar pressure changes and blood pressure parameters,with lower blood flow and higher mean vascular wall shear stress in the IAC with epilepsy group.Conclusions IAC may cause epilepsy by increasing adjacent blood vessel stenosis and blood vessel wall shear stress through cyst space-occupying effect.The most common location of IAC with epilepsy is the temporal area.The occupying effect of IAC should be considered in the location of epileptogenic foci before surgery for IAC patients with epilepsy.