Department of Radiology, Chi-Mei Medical Center, Tainan, Taiwan.
Graduate Institute of Medical Sciences, Chang Jung Christian University, Tainan, Taiwan.
BMC Neurosci. 2021 Dec 11;22(1):77. doi: 10.1186/s12868-021-00681-w.
Trigeminal neuralgia (TN) is the most common type of chronic neuropathic facial pain, but the etiology and pathophysiological mechanisms after treatment are still not well understood. The purpose of this study was to investigate the longitudinal changes of the cisternal segment of the trigeminal nerve and brain pain-related regions in patients with TN before and after treatment using readout segmentation of long variable echo-train (RESOLVE) diffusion tensor imaging (DTI) and transverse relaxation (T2)-weighted sampling perfection with application-optimized contrast at different flip angle evolutions (T2-SPACE).
Twelve patients with TN and four healthy controls were enrolled in this study. All patients underwent assessment of the visual analog scale (VAS), and acquisition of RESOLVE DTI and T2-SPACE images before and at 1, 6, and 12 months after treatments. Regions-of-interest were placed on the bilateral anterior, middle, and posterior parts of the cisternal segment of the trigeminal nerve, the bilateral root entry zone (REZ), bilateral nuclear zone, and the center of pontocerebellar tracts, respectively. Voxel-based morphometry (VBM) analysis was conducted with T2-SPACE images, and gray matter volumes (GMV) were measured from brain pain-matrix regions.
The results demonstrated that the VAS scores, the axial diffusivity of the middle part of the affected cisternal trigeminal nerve, the fractional anisotropy of the bilateral nuclear zones, and the mean diffusivity of the center of pontocerebellar tract significantly changed over time before and after treatment. The changes of GMV in the pain-matrix regions exhibited similar trends to the VAS before and after treatment.
We conclude that magnetic resonance imaging with RESOLVE DTI and VBM with T2-SPACE images were helpful in the understanding of the pathophysiological mechanisms in patients with TN before and after treatment.
三叉神经痛（TN）是最常见的慢性神经性面部疼痛类型，但治疗后的病因和病理生理机制仍未得到很好的理解。本研究旨在使用读出分割长变量回波列车（RESOLVE）扩散张量成像（DTI）和横向弛豫（T2）加权采样完美应用优化对比在不同翻转角演化（T2-SPACE）下，研究 TN 患者治疗前后三叉神经池段的纵向变化和与脑痛相关的区域。
本研究纳入了 12 例 TN 患者和 4 名健康对照者。所有患者均进行了视觉模拟评分（VAS）评估，并在治疗前、治疗后 1、6 和 12 个月采集 RESOLVE DTI 和 T2-SPACE 图像。在双侧三叉神经池段的前、中、后部分、双侧神经根入口区（REZ）、双侧核区和桥脑小脑束中心分别放置感兴趣区。使用 T2-SPACE 图像进行基于体素的形态计量学（VBM）分析，从脑痛基质区域测量灰质体积（GMV）。
结果表明，VAS 评分、受影响的三叉神经池段中部的轴向弥散度、双侧核区的各向异性分数和桥脑小脑束中心的平均弥散度在治疗前后随时间变化显著。疼痛基质区域 GMV 的变化与治疗前后的 VAS 相似。
我们得出结论，RESOLVE DTI 磁共振成像和 T2-SPACE 图像的 VBM 有助于理解治疗前后 TN 患者的病理生理机制。
