Chen Shu-Tian, Yang Jen-Tsung, Yeh Mei-Yu, Weng Hsu-Huei, Chen Chih-Feng, Tsai Yuan-Hsiung
Department of Diagnostic Radiology, Chang Gung Memorial Hospital at Chiayi, Chiayi, Taiwan.
Department of Neurosurgery, Chang Gung Memorial Hospital at Chiayi, Chiayi, Taiwan.
PLoS One. 2016 Dec 20;11(12):e0167584. doi: 10.1371/journal.pone.0167584. eCollection 2016.
Trigeminal neuralgia is characterized by facial pain that may be sudden, intense, and recurrent. Our aim was to investigate microstructural tissue changes of the trigeminal nerve in patients with trigeminal neuralgia resulting from neurovascular compression by diffusion tensor imaging, and to test the predictive value of diffusion tensor imaging for determining outcomes after radiofrequency rhizotomy. Forty-three patients with trigeminal neuralgia were recruited, and diffusion tensor imaging was performed before radiofrequency rhizotomy. By selecting the cisternal segment of the trigeminal nerve manually, we measured the volume of trigeminal nerve, fractional anisotropy, apparent diffusion coefficient, axial diffusivity, and radial diffusivity. The apparent diffusion coefficient and mean value of fractional anisotropy, axial diffusivity, and radial diffusivity were compared between the affected and normal side in the same patient, and were correlated with pre-rhizotomy and post-rhizotomy visual analogue scale pain scores. The results showed the affected side had significantly decreased fractional anisotropy, increased apparent diffusion coefficient and radial diffusivity, and no significant change of axial diffusivity. The volume of the trigeminal nerve on affected side was also significantly smaller. There was a trend of fractional anisotropy reduction and visual analogue scale pain score reduction (P = 0.072). The results suggest that demyelination without axonal injury, and decreased size of the trigeminal nerve, are the microstructural abnormalities of the trigeminal nerve in patients with trigeminal neuralgia caused by neurovascular compression. The application of diffusion tensor imaging in understanding the pathophysiology of trigeminal neuralgia, and predicting the treatment effect has potential and warrants further study.
三叉神经痛的特点是面部疼痛，可能突发、剧烈且反复发作。我们的目的是通过扩散张量成像研究因神经血管压迫导致三叉神经痛的患者三叉神经的微观结构组织变化，并测试扩散张量成像对确定射频神经根切断术后结果的预测价值。招募了43例三叉神经痛患者，并在射频神经根切断术前进行了扩散张量成像。通过手动选择三叉神经的脑池段，我们测量了三叉神经的体积、分数各向异性、表观扩散系数、轴向扩散率和径向扩散率。比较了同一患者患侧和正常侧的表观扩散系数以及分数各向异性、轴向扩散率和径向扩散率的平均值，并将其与神经根切断术前和术后视觉模拟评分疼痛分数相关联。结果显示，患侧分数各向异性显著降低，表观扩散系数和径向扩散率增加，轴向扩散率无显著变化。患侧三叉神经的体积也显著减小。存在分数各向异性降低和视觉模拟评分疼痛分数降低的趋势（P = 0.072）。结果表明，无轴突损伤的脱髓鞘以及三叉神经大小减小是神经血管压迫所致三叉神经痛患者三叉神经的微观结构异常。扩散张量成像在理解三叉神经痛的病理生理学以及预测治疗效果方面的应用具有潜力，值得进一步研究。
