摘要
目的采用3．0TMRI显示三叉神经及周围血管的解剖关系，分析产生原发性三叉神经痛（TN）的血管压迫特点。方法选择50例TN患者（50支TN患侧和50支TN对侧三叉神经；其中23例行微血管解压术）和50名没有面部疼痛的志愿者（100支非TN三叉神经），在3．0TMR采用三维快速稳态梯度回波序列（3DTRU．FISP）及3D三维时间飞跃（TOF-MRA）扫描。若判断TN患者为静脉病变，并行增强3D快速小角度反转序列（3DFLASH）扫描。以上图像融合重建成虚拟脑池图，评价神经血管压迫程度分级（1级无压迫，2级静脉性压迫，3级神经与动脉接触，4级有动脉压痕，5级动脉压迫导致神经明显移位），以及血管接触神经的方位（三叉神经的上侧或其他侧）、血管神经接触点的位置（近：位于三又神经脑池段近脑干1／3长度区域，远：位于三叉神经脑池段远脑干2／3长度区域）。3DTRU-FISP序列重建的冠、矢状面图像用于测量神经长度、神经横截面及脑池面积。采用卡方检验观察2组的三叉神经：血管压迫神经引起神经切迹或移位（4级和5级）、血管神经压迫点和神经出脑干处距离、血管压迫神经的位置位于神经上侧方的发生率。采用t检验观察测量数值的统计学意义，并用Logistic回归分析三叉神经痛的发病因素。结果两序列及融合图像可以清晰显示神经血管的关系，与23例微血管解压术中所见吻合度高，术后症状消失或明显减轻21例。血管压迫或接触三叉神经的发生率在志愿者组（1级79支，2级5支，3级8支，4级8支）、TN对侧（1级27支，2级6支，3级9支，4级8支）及TN患侧（1级4支，2级12支，3级12支，4级7支，5级15支）分别为21．0％（21／100）、46．0％（23／50）、92．0％（46／50）。TN患侧三叉神经较志愿者三又神经血管受压迫程度4、5级者差异有统计学意义（X^2=27．0，P〈0．01）；血管接触点的位置在TN患侧近32支、远14支，在志愿者近4支、远17支（X^2=14．8，P〈0．01）；压迫血管位置中，TN患侧位于神经上侧36支、其他侧10支，志愿者中位于神经上侧5支、其他侧16支（X^2=18．0，P〈0．01）；所在层面脑桥池面积，TN患侧为（183．9±52．5）mm^2、对侧为（217．8±58．8）mm^2（t=-3．04，P〈0．01）；脑池段神经中点截面积，TN患侧为（6．3±1．3）mm^2、对侧为（7．7±1．6）mm。（t=-4．8，P〈0．0）；脑池段神经长度，TN患侧为（8．0±1．9）mm、对侧为（9．0±2．0）mm（t=-2．64，P〈0．05），差异均有统计学意义。结论MR可以清楚显示TN患者血管与三叉神经的关系，受压迫神经位置更靠神经近端及头侧、神经所在层面脑桥池面积较小者，均是较强的手术指征。
Objective To identify anatomical characteristics of neurovascular compression associated with trigeminal newralgia（TN）. Methods Fifty patients with TN （23 of 50 patients underwent mierovascular decompression） and 50 patients without facial pain underwent 3.0 T MRI scanning for analysis of 50 trigeminal nerves ipsilateral to TN symptoms, 50 eontralateral to TN symptoms, and 100 in asymptomatic patients. MRI sequences included balanced fast-field echo and 3D MR angiography. Imageswere fused and reconstructed into virtual cisternoscopy images to determine the degree （severity of compression was defined as follows ： 1 = no compression ; 2 = compressed by a vein; 3 = contacted by an artery; 4 = indented by an artery; and 5 = nerve displaced or distorted by an artery） and site of neurovascular compression （ the point of each offending vascular structure ： proximal was defined as located in 1/3 length of the cisternal segment of the trigeminal nerve near root entry zone; the place of superior was defined as above the cisternal segment of the trigeminal nerve）. Reconstructed MPR images were used to measure nerve length and cross sectional area. The ehi-square test was used for all 2 x 2 contingency tables. The t-test was used for dependent samples. The Logistic regression was used for prediction of occurrence of the event of TN. Results Twenty-three of 50 patients with TN underwent microvascular decompression, which confirmed predicted neurovascular relationships in all cases, and 21 of 23 patients were pain free after the operation. The incidence of neurovascular compression on asymptomatic nerves （ no. of level 1 = 79, level 2 = 5, level 3 = 8, level 4 = 8 ） , on nerves contralateral to TN symptoms （ no. of level 1 = 27, level 2 = 6, level 3 =9, level 4 =8） , and on nerves ipsilateral to TN symptoms（no, of level 1 =4, level 2 = 12, level 3 = 12, level 4 =7, level 5 = 15） was 21.0% （21/100）, 46. 0% （23/50）, and 92. 0% （46/50）, respectively. The difference between symptomatic and asymptomatie nerves was significant regarding nerve distortion （ level 4 and 5, X^2 = 27.0 ,P 〈 0. 01 ） , the point of compression （ no. of proximal of symptomatic nerves = 32, not proximal of symptomatic nerves = 14, proximal of asymptomatic nerves = 4, not proximal of asymptomatic nerves = 17, X^2 = 14. 8, P 〈 0.01 ） , the place of vascular compression （no. of superior of symptomatic nerves = 36, not superior of symptomatic nerves =10, superior of asymptomatie nerves = 5, not superior of asymptomatic nerves = 16, X^2 = 18.0 ,P 〈 0. 01 ） and the mean cross-sectional area of the CPA cistern [ ipsilateral： （ 183.9 ± 52. 5 ） mm^2 , contralateral： （217.8 ± 58.8 ）mm^2 , t = - 3.04, P 〈 0.01 ]. Decreased nerve size was observed in patients with TN [ the section area of ipsilateral nerve （ 6. 3 ± 1.3） mm2, contralateral （7. 7 ± 1.6） mm^2, t = - 4. 80, P 〈 0. 01 ; length of ipsilateral nerve： （ 8.0 ± 1.9 ） mm, contralateral： （9.0 ± 2. 0） mm,t = - 2. 64,P 〈 0. 05 ]. Conclusions Trigeminal neurovascular compression can occur in asymptomatic patients, but is more severe, more proximal, more superior and with smaller size of cross-sectional area of the CPA cistern in patients with TN. This information may help identify patients who are likely to benefit from microvascular decompression.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2012年第6期494-499,共6页
Chinese Journal of Radiology
关键词
三叉神经痛
血管
磁共振成像
Trigeminal neuralgia
Blood vessels
Magnetic resonance imaging
