原发性三叉神经痛:三叉神经微观结构与神经脑桥夹角的相关性

Correlation analysis between the changes of trigeminal nerve microstructure and the trigeminal-pontine angle in primary trigeminal neuralgia patients

目的:探讨原发性三叉神经痛患者(PTN)三叉神经的微观结构改变与三叉神经-脑桥夹角之间的相关性。方法:将25例经微血管减压术(MVD)证实存在神经血管压迫(NVC)的单侧PTN患者和25例健康志愿者(对照组)纳入本研究,两组受试者均采用3D-FIESTA及DTI序列行MRI扫描,测量双侧三叉神经脑池段的长度、三叉神经-脑桥夹角、桥小脑角池横截面积以及NVC部位的扩散参数(FA、ADC)值,并分别对神经-脑桥夹角与扩散参数值及二者与视觉模拟评分(VAS)和病程等临床指标进行相关性分析。结果:PTN组患侧神经-脑桥夹角明显小于健侧和对照组[患侧:(39.11±5.76)°,健侧:(49.00±7.59)°,对照组:(45.20±5.76)°;F=15.26,P<0.001];且当责任血管为小脑上动脉(SCA)时,患侧神经-脑桥夹角显著小于其它责任血管时的夹角[SCA:(36.69±4.90)°,非SCA:(43.42±4.65)°;U=156.5,P=0.002]。与健侧及对照组比较,患侧桥小脑角池的横截面积和脑池段神经长度的差异均无统计学意义(P>0.05),患侧三叉神经的FA值明显减小、ADC值明显增加(P均>0.05)。患侧神经-脑桥夹角与FA值呈正相关(r=0.56,P<0.01),与ADC值呈负相关(r=-0.62,P<0.01);FA值与VAS评分呈负相关(r=-0.53,P<0.01)。结论:三叉神经与脑桥的夹角可作PTN的临床诊断指标之一,FA值亦可作为一种评估PTN患者临床症状严重程度的指标。

Objective: The purpose of this study was to explore the correlation between the microstructural changes of trigeminal nerve and the trigeminal-pontine angle in patients with primary trigeminal neuralgia (TN). Methods: 25 TN patients with unilateral neurovascular compression (NVC) confirmed by microvascular decompression (MVD) and 25 healthy controls (HC) were enrolled in this study.All subjects underwent MRI examination using three-dimensional fast imaging employing steady- state acquisition (3D-FIESTA) sequence and diffusion tensor imaging (DTI).The length of the cisternal segments of trigeminal nerve,the trigeminal-pontine angle (TPA),areas of cerebellopontine angle cistern (ACAC),and FA and ADC at the site of NVC were measured on the post-processed images.Correlation analyses were performed between the TPA and the diffusion metrics (FA and ADC) and clinical variables including disease duration and visual analogy scale (VAS). Results: The TPA on the symptomatic side were smaller than that of the asymptomatic side and the control group [lesion side:(39.11±5.76)°,contralateral side:(49.00±7.59)°,HC:(45.20±5.76)°;F =15.26,P <0.001].When the conflicting vessels taken into consideration,the angle affected by the superior cerebellar artery (SCA) was statistically smaller than that affected by other vessels [SCA:(36.69±4.90)°,other vessel:(43.42±4.65)°;U =156.5,P =0.002].The mean values of FA were significantly decreased and the values of ADC were significantly increased at the site of NVC in patients.Correlation analysis showed that the TPA positively correlated with FA ( P <0.01,r =0.56),and negatively correlated with ADC ( P <0.01,r =-0.62);FA negatively correlated with VAS ( P <0.01,r =-0.53). Conclusion: Trigeminal-pontine angle may be a possible facilitating factor for PTN,thus may be used as a clinical diagnosis marker.In addition,FA can be used as a potential MRI biomarker to evaluate clinical severity of trigeminal neuralgia (TN).