血管压迫性三叉神经痛的扩散张量成像研究

The study of diffusion tensor imaging of trigeminal neuralgia with vascular compression

目的研究血管压迫性三叉神经痛(TN)患者三叉神经根部扩散张量成像(DTI)的磁共振表现及临床应用。方法 49例经手术证实的血管压迫引起单侧TN患者行常规MRI检查和横轴面DTI成像,根据血管与神经相互关系分为A组(接触,22例)、B组(移位,11例)、C组(压迫,16例),分别测量患侧及健侧三叉神经根部的横截面积(CSA)、平均扩散系数(MD)值、部分各向异性分数(FA)值、轴向扩散系数(AD)值和径向扩散系数(RD)值,比较患侧及健侧三叉神经以及TN患者组间患侧三叉神经各参数值的差异。结果患侧三叉神经CSA、FA值明显低于健侧,患侧MD值及RD值明显高于健侧,且差异均有统计学意义(P<0.05),患侧AD值与健侧比较差异无统计学意义(P>0.05)。A、B和C组的CSA、FA值、RD值之间差异有统计学意义,其中A组CSA和FA值高于C组,RD值低于C组;B组FA值高于C组,差异有统计学意义(P<0.05)。结论磁共振DTI序列可以反映三叉神经微观结构的改变,提示三叉神经脱髓鞘是由血管压迫引起的,为揭示TN的发病机制以及评估TN严重程度提供了可靠的依据。

Objective To study the findings and clinical application of the diffusion tensor imaging(DTI) of thetrigeminal nerve root in patients with trigeminal neuralgia(TN).MethodsForty-nine patients with unilateral TN caused byvascular compression and surgically confirmed were collected in this study. The subjects were divided into group A(contact,n=22), group B(displacement, n=11) and group C(atrophy, n=16), according to the relationship between blood vessels andnerves. Conventional MRI and horizontal DTI were performed to measure cross-sectional area(CSA), mean diffusivity(MD)value, fractional anisotropy(FA) value, axial diffusivity(AD) value and radial diffusivity(RD) value in nerve roots of affectedside and unaffected side. The trigeminal indexes of both affected and unaffected trigeminal nerves and data of the affectedtrigeminal indexes of TN patients were compared between the groups.ResultsThe CSA and FA values were significantlylower, MD and RD values of trigeminal nerves were significantly higher in affected side than those of unaffected side(P<0.05). But there was no significant difference in AD value between affected side and unaffected side of TN patients(P>0.05). Values of CSA and FA were significantly higher in group A than those of group C. The value of RD was significantlylower in group A than that of group C. FA value was significantly higher in group B than that of group C(P<0.05).ConclusionThe magnetic resonance DTI sequence can reflect changes in trigeminal nerve microstructure, suggesting thattrigeminal demyelination is caused by vascular compression, and altered diffusion indexes of trigeminal nerve are reliablebasis for the pathogenesis and the severity evaluation of TN.