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

Quan Zhang,Junpeng Liu,Jiajia Zhu,Xuejun Zhang,Fei Yuan

doi:10.1186/s10194-018-0871-1

Abstract

BackgroundIdiopathic 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.MethodsVisual 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.ResultsThe 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.ConclusionThese findings suggest that TN selectively impairs widespread white matter, especially contralateral hemisphere, which may be the hallmark of disease severity in TN patients.

Highlights

Idiopathic or classical trigeminal neuralgia (TN) is a chronic painful condition characterized by intermittent pain attacks
Correlations between clinical variables and altered Diffusion tensor imaging (DTI) metrics In the TN patients, negative correlations were observed between disease duration and the fractional anisotropy (FA) values of left anterior corona radiata (r = 0.211, P = 0.012), genu of corpus callosum (r = 0.166, P = 0.028), left external capsule (r = 0.190, P = 0.018), left cerebral peduncle (r = 0.192, P = 0.017), and between Visual Analogue Scale (VAS) and the FA values of left anterior corona radiata (r = 0.221, P = 0.010), left external capsule (r = 0.218, P = 0.011), left cerebral peduncle (r = 0.168, P = 0.027) (Fig. 2)
Positive correlations were observed for disease duration and the radial diffusivity (RD) values of left anterior corona radiata (r = 0.190, P = 0.018), right external capsule (r = 0.170, P = 0.026), left fornix cerebri (r = 0.168, P = 0.027), left cerebral peduncle

Summary

Introduction

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. Trigeminal neuralgia (TN) is the most common form of facial neuropathic pain with an annual incidence of 4 to 5 new patients per 100,000 [1]. It is characterized by recurrent episodes of unilateral brief electric shock-like pains localized to the sensory supply areas of trigeminal. Neurovascular compression may result in focal demyelination of the trigeminal nerve at the REZ, which generates ectopic discharges and pathological. Diffusion tensor imaging (DTI) based on magnetic resonance imaging (MRI) has been considered as a useful and effective examination of the trigeminal nerve system in great detail [8, 12, 17]

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Discussion

Conclusion