基于多模态磁共振、伤害感受评定及神经肽的三叉神经痛纵向性研究

Trigeminal neuralgia (TN), which is considered as the most common category of cranial neuralgia, usually demonstrate unbearable unilateral facial pain with progressive aggravation. In spite of definite etiology, there are wide individual variations in terms of curative effect and relapse, therefore, it is essential for us to evaluate treatment effectiveness with imaging methods on TN. In this project, the multi-modality MR techniques, including voxel based morphometry (VBM), diffusion tensor imaging (DTI), functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (MRS), are adopted to acquire the various image data on the patients with primary trigeminal neuralgia before and after gamma knife radiosurgery (GKRS), respectively. Then, the MR data are postprocessed with statistical parametric mapping 8 (SPM8) to acquire the volume, microstructure of whiter matter, activation characteristics and metabolism of the whole brain. Furthermore, visual analogue scale (VAS), short-form McGill questionnaire (SF-MPQ), as well as pain related neuropeptides, will be combined to analyze the dynamic correlation between the nociceptive clinical indicator (VAS, SF-MPQ, neuropeptides) and MR data in the effective treatment group and ineffective treatment group with GKRS. Results of the study will offer useful informations on pathogenetic condition, therapeutic effect, prognosis of TN in both the general and molecular level. Successful accomplishment of the study will help to quantitively evaluate the changes of brain of TN patients in pre-treament and post-treatment conditions with MRI techniques. Meanwhile, combination of the imaging data with nociceptive scales and biochemical index probably reflect the pain intensity more accurately, and also provide objective theoretical evidence for the efficacy evaluation using GKRS.

三叉神经痛(TN)是最常见的颅神经疼痛，临床症状常进行性加重。尽管其病因基本明确，但在疗效和复发方面个体差异很大，如何应用影像学评估三叉神经痛的治疗效果和复发情况有待于深入研究。本课题采用基于体素的形态学(VBM)、弥散张量成像(DTI)、功能磁共振成像(fMRI)、磁共振波谱(MRS)技术，在进行γ刀治疗前后分别获取原发性三叉神经痛患者的多模态MRI数据、痛觉主观指标(VAS和McGill评分)及客观指标(痛觉相关性神经肽含量)，揭示治疗有效组和无效组之间痛觉相关脑区灰白质容积、白质微结构、激活特性、代谢水平的差异，并与患者疼痛改善程度及痛觉相关性神经肽含量变化进行动态相关性分析，为三叉神经痛的病情、疗效和预后提供整体水平的资料。本课题将促进影像学对三叉神经痛的定量分析，并与VAS、McGill评分和痛觉相关神经肽相结合，更加真实地反映患者的痛觉水平，为γ刀治疗效果的评估提供客观依据。

背景：.特发性三叉神经痛(ITN)是最常见的颅神经痛，表现为三叉神经支配区的突发性电击样疼痛，可能与变异血管压迫桥池段三叉神经(NVC)有关。然而，约有40%的健康人群同样存在NVC，30%的患者解除NVC后2年内疼痛复发。应用磁共振数据可以揭示ITN患者脑结构、功能和代谢的异常特征，为其辅助诊断、优化治疗方案和疗效评估提供客观依据。.研究内容：.1、定量测定ITN患者与对照组桥池段三叉神经的最小横截面积(CSA)和体积(V)，比较组间三叉神经的形态学差异，并与疼痛评分(VAS)进行相关分析；.2、检测患者与对照组丘脑各亚区NAA/Cr及NAA/Cho的差异，并与病情和认知能力进行相关分析；.3、测定患者与对照组痛觉相关脑区灰质体积、白质完整性和功能连接强度，并与VAS、抑郁和焦虑评分进行相关分析。.重要结果：.1、ITN患者受累侧三叉神经的CSA和V均小于对照组，提示其存在萎缩征象。患者三叉神经萎缩程度与VAS呈显著负相关，与抑郁和焦虑评分也存在相关性；.2、与对照组相比，ITN患者患侧丘脑部分亚区的NAA/Cr、Cho/Cr有所下降。丘脑后内侧部 NAA/Cr与病程和VAS呈负相关，板内区Cho/Cr与认知能力呈正相关。.3、与对照组相比，ITN患者全脑灰质体积出现普遍性萎缩，累及扣带回前部及中部(ACC, MCC)、岛叶前部等脑区。同时，患者组胼胝体、放射冠FA值低于对照组，MD值高于对照组。最后，患者组右侧岛叶与ACC、扣带回后部(PCC)、双侧前额叶背外侧皮质(dlPFC)的功能连接均强于对照组，且岛叶-ACC功能连接与VAS及焦虑、抑郁评分均呈线性负相关。.关键数据：.1、桥池段三叉神经的CSA和V；.2、丘脑各亚区的NAA/Cr和Cho/Cr；.3、ACC、MCC、岛叶前部等脑区的灰质体积；胼胝体、放射冠等白质纤维束的FA和MD；岛叶-ACC、岛叶-PCC、岛叶-dlPFC的功能连接强度。.科学意义：.1、3D-FIESTA联合TOF-MRA是检测责任血管与三叉神经关系的可靠序列，ITN患者三叉神经萎缩可作为预测疼痛水平的重要影像学依据。.2、ITN患者患侧丘脑后内侧部NAA/Cr 降低程度对评估疼痛水平有重要作用，板内区Cho/Cr下降提示患者认知能力发生障碍。.3、右侧岛叶-ACC功能连接对预测ITN患者疼痛水平和情绪障碍程度具有重要意义。