前庭阵发症神经血管压迫影像学分析

MRI analysis of vestibulocochlear neurovascular compression in 28 patients with vestibular paroxysmia

目的 分析前庭阵发症神经血管压迫的MRI表现特点,并对血管压迫部位和程度在发病中的影响进行探讨.方法 收集28例前庭阵发症（vestibular paroxysmia,VP）患者,以28例其他眩晕病患者作为对照组,经三维-磁共振血管成像技术扫描,对两组患者前庭蜗神经周围有无神经血管交互压迫（neurovascular cross-compression,NVCC）、NVCC类型、责任血管来源及血管压迫部位至脑干的距离进行回顾性分析.结果 VP组NVCC阳性率（27/28,96.4％）显著高于对照组（13/28,46.4％,x2=17.15,P＜0.01）.VP组中最常见NVCC类型为血管襻形式压迫（15/35,42.9％）,最常见的责任血管为小脑前下动脉（25/35,71.4％）,VP组与对照组NVCC分型、责任血管来源差异均无统计学意义.血管严重压迫前庭蜗神经致其变形和（或）移位在VP组为12.5％ （7/56）,对照组为0,差异有统计学意义（P =0.013）.NVCC距脑干距离VP组为（8.57 ±5.08） mm,对照组为（8.93±4.64） mm,两组差异无统计学意义,但VP组中单侧NVCC距脑干的距离全部小于15 mm,对照组中为7/10,差异有统计学意义（P=0.033）.结论 VP患者NVCC的发生率较高,责任血管多为小脑前下动脉,以血管襻形式压迫前庭蜗神经多见,NVCC多发生在前庭蜗神经的中枢髓鞘部;血管压迫部位及程度与VP发病可能相关.

Objective To analyze the MRI characteristics of vestibulocochlea neurovascular compression in patients with vestibular paroxysmia （VP） and to investigate the effect of the compression,its site and degree,on the occurrence of VP.Methods Twenty-eight cases of VP （VP group） and 28 cases of vertiginous patients other than VP （control group） were retrospectively reviewed.Three dimensional magnetic resonance angiography （3D-MRA） was performed and the data were used for neurovascular crosscompression （NVCC） analysis.The frequency and type of NVCC,the origin of the offending vessel and the distance between compression site and brainstem were compared between the two groups.Results The frequency of NVCC was 96.4％ （27/28） in VP group,with a significant difference compared with control group （13/28,46.4％ ;x2 =17.15,P ＜0.01）.The most common NVCC type was vascular loop compression at vestibulocochlear nerve （15/35,42.9％）.Anterior inferior cerebellar artery was the most common offending vessel （25/35,71.4％） in VP group.There were no significant differences between the two groups in the type of NVCC or the origin of the offending vessel.The frequency on the distortion and （or） displacement of vestibulocochlear nerve which was severely compressed by vessel in VP group （7/56,12.5％） was significantly higher than that in control group （0; P =0.013）.The distance between compression site and brainstem was （8.57 ± 5.08） mm in VP group,and （8.93 ± 4.64） mm in control group,showing no significant difference.The ratio that the distance was less than 15 mm between compression site and brainstem in unilateral NVCC of VP group （100％） was significantly higher than unilateral NVCC of control group （7/10,P =0.033）.Conclusions The VP patients have higher NVCC incidence and the most common NVCC type is vascular loop compression at vestibulocochlear nerve which is mainly caused by anterior inferior cerebellar artery.NVCC in VP patients mostly occurs in the central myelin portion of vestibulocochlear nerve.The site and degree of neurovascular compression may relate to the occurrence of VP.