Application of diffusion tensor imaging in detecting microstructural alteration of the trigeminal nerve root in patients with classical trigeminal neuralgia without neurovascular compression

Abstract Background Diffusion tensor imaging (DTI) was used to detect microstructural alteration and influence of surgical intervention of the trigeminal nerve root (TR) in patients with classical trigeminal neuralgia (CTN) without neurovascular compression (woNVC) who had undergone internal neurolysis (IN). Methods Overall, 21 patients with CTN woNVC who underwent IN and 20 healthy controls were included prospectively. The differences in the means, kurtosis and skewness of each of the diffusivity metrics between the affected and unaffected nerves in patients and both nerves in controls, were then analyzed using the independent t test. Data from the affected side and the unaffected side before and 1 years after IN were compared. Results There were significantly different mean and kurtosis values for both FA and ADC of the affected side TR, compared to the unaffected side and control group respectively before IN. 1 year after surgery, most of these differences significantly reduced in comparison between the affected side and unaffected side, the affected side and control group, and these trends were also in accordance with the relief of pain. The Pearson correlation coefficient showed a strong negative correlation between decrease of ADC in the affected side compared to the surgical outcome in BNI total score. Conclusions The changes of diffusive property of TR could explain the efficiency of IN. The pretreatment DTI metrics could be an effective prognostic factor for providing potential noninvasive, brain-based biomarkers to support an optimal treatment selection for individual patients with CTN woNVC.