Sturge-Weber综合征癫痫发作与脑血流动力学的相关性研究

目的应用动态磁敏感增强MR灌注成像(DSC-PI)技术对Sturge-Weber综合征(SWS)受累白质区的血流灌注进行定量测量,并和各种癫痫状态指标进行相关性分析,以期合理的解释SWS血流动力学与癫痫状态的关系。材料与方法 14例临床确诊为SWS的患儿进行MRI检查,其中男6例,女8例,平均年龄4.0岁(0.8～10.0岁)。所有患儿的病变部位均为单侧大脑半球。MR扫描序列包括:矢状面及轴面T1WI、轴面FSET2WI、DSC-PI及增强后轴面T1WI。观察所有图像以确认脑内病变位置及范围;利用SPIN(signal process in neuroimage)软件分别测量病变白质区域及相应对侧位置的脑血流量(CBF)、脑血容量(CBV)和平均通过时间(MTT),并计算出灌注比值(CBFr、CBVr及MTTr)。根据CBFr值将患儿分为高灌注组(HP)及低灌注组(LP)。记录每例患儿的临床资料,尤其有无癫痫发作以及反映发作的各项参数:首次癫痫发作年龄、癫痫发作频率(SSF)及癫痫持续时间。对高、低灌注组病变侧与对侧的CBF、CBV及MTT值进行配对秩和检验;对癫痫状态的各临床参数与各项灌注参数进行Spearman相关分析。结果 14例SWS患者中,9例受累白质区CBF及CBV较对侧明显减低(CBFr值为-0.37±0.24,CBVr=-0.22±0.25,P值均<0.01),为LP组;5例脑内病变侧白质区CBF及CBV较对侧显著增高(CBFr值为0.31±0.05,CBVr值为0.40±0.17,P值均<0.01),为HP组。LP组年龄及癫痫发作频率得分(SSF)较HP组有增大趋势(年龄=63.80月,48.83月;SSF=2.50,1.33),但这差异缺乏统计学意义(P值分别为0.36、0.12)。病变侧CBFr值和CBV值与癫痫持续时间呈明显负相关(CBFr:r=-0.58;CBV:r=-0.55,P值均<0.05)。CBFr和CBVr与癫痫发作频率呈负相关,即癫痫发作越频繁,CBFr和CBVr越低(CBFr:r=-0.56;CBVr:r=-0.63,P值均<0.05)。结论 SWS受累白质区域的血流灌注并非持续降低,而存在相对高灌注状态;灌注异常与癫痫发作的频率和癫痫持续时间有关。

The correlation study of seizure and cerebral hemodynamics in Sturge-Weber syndrome

Objective： To evaluate the perfusion status of involved white matter in Sturge-Weber syndrome （SWS） using dynamical susceptibility contrasted perfusion imaging （DSC-PI）, and then to compare the perfusion data and seizure variables, including age of first seizure, seizure frequency （score of seizure frequency, SSF） and duration of epilepsy, for reasonable explaining the hemodynamics and seizure variables in SWS. Materials and Methods： 14 patients （8 girls and 6 boys; age range, 0.8-10.0 years; median age, 4.0 years） with Sturge-Weber syndrome were recruited and performed MR! examination. All patients with unilateral lesions were located in one side of the cerebral hemispheres. MR protocols included axial and sagittal Tl-weighted, axial fast spin-echo （FSE） T2-weighted, DSC-PI and contrasted TI- weighted. All raw data of DSC-PI were processed through the SPIN software （signalprocess in neuroimage）. After determining the location and realm of SWS lesions, the CBF, CBV and MTT value of the affected and contralateral white matter were measured, and then the ratio of perfusion data, including CBFr, CBVr and MTTr were calculated. According to the CBFr values, all cases were divided into hyperperfusion group （HP） and hypoperfusion group （LP）. The comparison of CBF, CBV and MTT values between the affected and contralateral hemispheres was tested by Mann-Whitney＇ U analysis. The correlations of all perfusion data and seizure variables （age of first seizure, SSF and duration of epilepsy） were analyzed by Spearman correlation analysis. Results： In all, nine cases belonged to the LP group according to the significantly decreased CBF and CBV in the affected white matter compared to those in the contralateral＇s （CBFr =--0.37~0.24, CBVr=-- 0.22___0.25, P〈0.01）, and the other 5 cases were in the HP group based on the significantly increased CBF and CBV of affected white matter （CBFr =0.31 _ 0.05; CBVr=0.40 -＋- 0.17, P〈0.01）. The age and SSF of LP group were slightly higher than HP group （age were 63.80 months ＆ 48.83 months; SSF were 2.50 ＆ 1.33）, but no significant difference was present respectively （P=0.36, 0.12）. Longer duration of epilepsy was related to lower CBF （more negative CBFr, r=-0.58, P〈0.05） and low CBV （r=-0.55, P〈0.05） on the affected side. Lower perfusion was associated with more frequent seizures （CBFr： t-=-0.56, CBVr： r=-0.63, P〈0.05）. Conclusions： The perfusion of affected white matter in Sturge-Weber syndrome did not decrease continuously as illustrated by previous studies, whiles the relatively hyperperfusion was considered as a common phenomena. There are relationshios between brain oerfusion status and seizure severity in SWS.