Study on the MR imaging characteristics of primary trigeminal neuralgia

Objective To analyze the imaging characteristics of vascular nerve compression(NVC)with trigeminal neuralgia(TN) through the two sequences imaging of MR 3D-FIESTA and 3D-TOF.Methods 50 cases of patients of the type Ⅰ TN and 25 cases of normal patients were scanned by the two sequences imaging of MR 3D-FIESTA and 3D-TOF on each 1 mm,and the extent and location of the NVC were statistically analyzed with the applications of the sequences.Results That NVC was shown by MR had 45 cases among the 50 cases of TN,and 5 cases did not display NVC.Both of them were confirmed by the operation.NVC were not detected through interoperation in the two cases of the eight cases with mild NVC;37 cases with moderate or severe oppression had been confirmed,and 1 case existed in NVC in the 5 cases with no NVC during surgery.The difference of moderate and severe NVC existed in difference statistically between symptoms side and the normal side(P0.01),while the difference was not statistically significant in simple NVC(P0.05).The distance from maximum compression of NVC to nerve root which entries into the brainstem was analyzed about the aspect of symptoms side and the normal side,and which revealed higher appearance on the symptoms side when the distance was proximal and less than 3.75 mm.Conclusions It suggested that TN would be activated if NVC existed in the severe oppressions or more proximal and less than 3.75 mm from the root entry zone(REZ).