Willsey Matthew S, Collins Kelly L, Conrad Erin C, Chubb Heather A, Patil Parag G
1Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
2Department of Neurosurgery, University of Washington, Seattle, Washington.
J Neurosurg. 2019 Jul 19;133(2):573-579. doi: 10.3171/2019.4.JNS19299. Print 2020 Aug 1.
Trigeminal neuralgia (TN) is an uncommon idiopathic facial pain syndrome. To assist in diagnosis, treatment, and research, TN is often classified as type 1 (TN1) when pain is primarily paroxysmal and episodic or type 2 (TN2) when pain is primarily constant in character. Recently, diffusion tensor imaging (DTI) has revealed microstructural changes in the symptomatic trigeminal root and root entry zone of patients with unilateral TN. In this study, the authors explored the differences in DTI parameters between subcategories of TN, specifically TN1 and TN2, in the pontine segment of the trigeminal tract.
The authors enrolled 8 patients with unilateral TN1, 7 patients with unilateral TN2, and 23 asymptomatic controls. Patients underwent DTI with parameter measurements in a region of interest within the pontine segment of the trigeminal tract. DTI parameters were compared between groups.
In the pontine segment, the radial diffusivity (p = 0.0049) and apparent diffusion coefficient (p = 0.023) values in TN1 patients were increased compared to the values in TN2 patients and controls. The DTI measures in TN2 were not statistically significant from those in controls. When comparing the symptomatic to asymptomatic sides in TN1 patients, radial diffusivity was increased (p = 0.025) and fractional anisotropy was decreased (p = 0.044) in the symptomatic sides. The apparent diffusion coefficient was increased, with a trend toward statistical significance (p = 0.066).
Noninvasive DTI analysis of patients with TN may lead to improved diagnosis of TN subtypes (e.g., TN1 and TN2) and improve patient selection for surgical intervention. DTI measurements may also provide insights into prognosis after intervention, as TN1 patients are known to have better surgical outcomes than TN2 patients.
三叉神经痛（TN）是一种罕见的特发性面部疼痛综合征。为了辅助诊断、治疗和研究，当疼痛主要为阵发性和发作性时，TN常被分类为1型（TN1）；当疼痛主要为持续性时，则被分类为2型（TN2）。最近，扩散张量成像（DTI）揭示了单侧TN患者有症状的三叉神经根及神经根入区的微观结构变化差异。在本研究中，作者探讨了TN的亚类，特别是TN1和TN2在三叉神经束脑桥段的DTI参数差异。
作者纳入了8例单侧TN1患者、7例单侧TN2患者和23例无症状对照者。患者接受DTI检查，并在三叉神经束脑桥段的感兴趣区域测量参数。对各组之间的DTI参数进行比较。
在脑桥段，TN1患者的径向扩散率（p = 0.0049）和表观扩散系数（p = 0.023）值高于TN2患者和对照者。TN2患者的DTI测量值与对照者相比无统计学意义。在比较TN1患者有症状侧和无症状侧时，有症状侧的径向扩散率增加（p = 0.025），分数各向异性降低（p = 0.044）。表观扩散系数增加，有统计学意义的趋势（p = 0.066）。
对TN患者进行无创DTI分析可能有助于改善TN亚型（如TN1和TN2）的诊断，并改善手术干预的患者选择。DTI测量还可能为干预后的预后提供见解，因为已知TN1患者的手术效果优于TN2患者。
