Prumary trigeminal neuralgia (PTN) is supposedly caused by an ectatic blood vessel affecting the trigeminal nerve at the root entry zone of the brain stem, i.e. a neurovascular conflict (NVC). Recent evidence suggests an additional central component within trigeminal pain-processing in the pathophysiology of PTN. Consistently with this hypothesis structural grey and white matter alterations and functional cerebral changes in PTN patients have been described. In this study, we aim at investigating the link between NVC, trigeminal nerves and brain changes in PTN patients (TRI) compared to healthy controls (HC). Moreover, we will explore the association with clinical variables. Fifty patients with PTN will be enrolled in this study. Fifty matched HC will be also included. All subjects will undergo a complete neuropsychological assessment and MRI scan with a 3T system (Verio, Siemens). The MRI exam will include conventional sequences to identify neurovascular conflict, 3D-T2-weighted CISS sequences to obtain a quantitative evaluation of nerve volume, T1-FSPGR sequences to perform calculation of grey matter volumes using, BOLD fMRI sequences to evaluate functional brain connectivity. Data analysis will consist in evaluation of severity of neurovascular conflict (NVC: grade 0 no contact between nerve and vessel, grade 1 contact, grade 2 distortion or dislocation of nerve) quantitative evaluation of nerve volume and nerve volume asymmetry using MIPAV, quantification of grey matter volumes using voxel-based morphometry (VBM), surface based morphometry (SBM) and regional based morphometry (RBM) (CAT, SPM12), analysis of functional connectivity using both seed analysis and independent component analysis (CONN, SPM12). Statistical analysis will be conducted to investigate the relationship between clinical variables (age, duration of disease, pain intensity, duration and frequency of attacks) and MR imaging data (SPSS 25).
