Abnormal brain white matter in patients with right trigeminal neuralgia: a diffusion tensor imaging study

Abstract Background Idiopathic or classical trigeminal neuralgia (TN) is a chronic painful condition characterized by intermittent pain attacks. Enough evidence demonstrates classical TN is related to neurovascular compression (NVC) at the trigeminal root entry zone (REZ), but white matter change secondary to TN are not totally known. Methods Visual Analogue Scale (VAS) and diffusion tensor imaging were performed on 29 patients with right TN and 35 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). Group differences in these parameters were compared between right TN patients and controls using TBSS and correlations between the white matter change and disease duration and VAS in right TN patients were assessed. Multiple comparison correction were applied to test significant correlations. Results The right TN patients showed significantly lower FA and higher RD in most left white matter (P < 0.05, FWE corrected). Moreover, negative correlations were observed between disease duration and the FA values of left corona radiata, genu of corpus callosum, left external capsule and left cerebral peduncle, and between VAS and the FA values of left corona radiata, left external capsule and left cerebral peduncle (P < 0.05). Positive correlations were observed for disease duration and the RD values of left corona radiata, right external capsule, left fornix cerebri and left cerebral peduncle, and for VAS and the RD values of left corona radiata and left external capsule (P < 0.05). However, once Bonferroni corrections were applied, these correlations were not statistically significant. Conclusion These findings suggest that TN selectively impairs widespread white matter, especially contralateral hemisphere, which may be the hallmark of disease severity in TN patients