BACKGROUND Morphological and microstructural changes of the trigeminal nerve due to neurovascular compression (NVC) have been reported in primary trigeminal neuralgia (PTN) patients. This investigation was to examine the relationship between the trigeminal-pontine angle and nerve microstructural changes. METHODS Twenty-five patients underwent microvascular decompression (MVD) for trigeminal neuralgia, and 25 age- and sex-matched controls were studied. The two groups underwent high-resolution three-dimensional MRI and diffusion tensor imaging (DTI). Bilateral trigeminal-pontine angle, cross-sectional area of cerebellopontine angle (CPA) cistern, and the length of trigeminal nerve were evaluated. The mean values of fractional anisotropy and apparent diffusion coefficient at the site of NVC were also measured. Correlation analyses were performed for the trigeminal-pontine angle and the diffusion metrics (FA and ADC) in PTN patients. RESULTS The mean trigeminal-pontine angle and FA value on the affected side was significantly smaller than the unaffected side and the control group (p < 0.001), while the mean ADC value was significantly increased (p < 0.01). When taking the conflicting vessel types into consideration, the angle affected by the superior cerebellar artery (SCA) was statistically sharper than when affected by other vessels (p < 0.01). However, there were no significant changes in the area of the CPA cistern or the length of the trigeminal nerve between the groups. Correlation analyses showed that the trigeminal-pontine angle was positively correlated with FA and negatively correlated with ADC. CONCLUSIONS A sharp trigeminal-pontine angle may increase the chance of NVC and exacerbate nerve degeneration, which may be one of the supplementary factors that contribute to the pathogenesis of trigeminal neuralgia.

中文翻译：

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三叉神经的微结构变化与三叉-桥脑角度特征之间的相关性。

背景技术在原发性三叉神经痛（PTN）患者中已经报道了由于神经血管压迫（NVC）引起的三叉神经的形态和微结构改变。这项研究是要检查三叉神经桥角与神经微结构变化之间的关系。方法25例因三叉神经痛而接受微血管减压术（MVD）的患者，对25位年龄和性别相匹配的对照者进行了研究。两组均接受了高分辨率三维MRI和扩散张量成像（DTI）。评价双侧三叉神经-桥脑角，小脑桥脑角（CPA）池的横截面积和三叉神经的长度。还测量了NVC部位的分数各向异性和表观扩散系数的平均值。对PTN患者的三叉－桥脑角和扩散指标（FA和ADC）进行了相关分析。结果患侧平均三叉－桥脑角和FA值显着小于未患侧和对照组（p <0.001），而平均ADC值则显着增加（p <0.01）。考虑到冲突的血管类型时，小脑上动脉（SCA）影响的角度在统计学上比其他血管影响的角度更锐利（p <0.01）。但是，两组之间CPA池的面积或三叉神经的长度没有明显变化。相关分析表明，三叉神经-桥脑角与FA呈正相关，与ADC呈负相关。