Explore White Matter Myelin Integrity By Using Diffusion Tensor Imaging In Patients With Right Trigeminal Neuralgia

Background:Trigeminal neuralgia(TN)is a chronic painful condition characterized by intermittent pain attacks.The reasons of TN include nerve vascular compression(NVC),multiple sclerosis,tumors,arteriovenous malformations,and facial injuries,NVC considered as the most common cause.NVC can lead to chronic demyelination and abnormal conduction of the trigeminal nerve,which leads to structural disorder,abnormal discharge and atrophy.And pain comes along with it.In recent years,some studies have reported that TN may lead to white matter changes,but the etiology and mechanism of CNS changes in TN are not totally known.In response to this problem,our study apply DTI and TBSS method to study the secondary changes of white matter in TN patients.Methods:Visual Analogue Scale/Score(VAS)and diffusion tensor imaging were performed on 29 patients with right TN and 35 matched healthy individuals.Voxel-wise analyses were performed with TBSS using multiple diffusion metrics,including fractional anisotropy(FA),mean diffusivity(MD),axial diffusivity(AD)and radial diffusivity(RD).White matter brain regions were found with significant differences between groups.Correlations between the ROI and disease duration and VAS in right TN patients were assessed.Results:The right TN patients showed significantly lower FA and higher RD in most left white matter(p < 0.05,FWE corrected).Moreover,we found significantly negative correlations between disease duration and the FA values of left corona radiata,genu of corpus callosum,left external capsule and left cerebral peduncle,and significantly negative correlations between VAS and the FA values of left corona radiata,left external capsule and left cerebral peduncle.In addition,we also found significantly positive correlations between disease duration and the RD values of left corona radiata,right external capsule,left fornix cerebri and left cerebral peduncle,and significantly positive correlations between VAS and the RD values of left corona radiata and left external capsule.Conclusion:There was a significant difference in white matter integrity between right TN patients and healthy controls,indicating that white matter damage was present in TN patients.The TBSS method demonstrated that the main mechanism of white matter damage may be white matter demyelination and nerve inflammation.In addition,our study also shows that white matter damage becomes more and more serious as the disease develops and the pain increases.