Structural changes of trigeminal nerve after microvascular decompression by magnetic resonance diffusion tensor imaging

doi:10.3969/j.issn.1009-6574.2016.04.004

Abstract：Objective To evaluate the microstructural changes of trigeminal nerve by using mag-netic resonance diffusion tensor imaging (DTI) sequence in patients with trigeminal neuralgia (TN) after microvascular decompression (MVD) .Methods Nine patients with primary TN were evaluated by DTI before and after MVD .The FA ,MD ,AD ,RD and difference ratio of the bilateral dispersion parameters were calculated .Patients were divided into two groups according to final results of MVD :cure group and not cure group .The changes of parameters of DTI were compared between bilateral before and after MVD .Results Six male and three women were included .The mean age was 52 .1 years ,and mean course of disease was 5 .1 years .DTI was used at the first review (average 12 .3 months) ,the average follow -up was 66 months after operation .Six patients were complete recovery (all had obvious vascular com-pression ,the trigeminal nerve was compressive deformation) ,while 3 patients remaining suffered TN (2 patients had vascular compression ,1 patients had severe subarachnoid adhesions and without vascular compression) .In the cure group ,the decreased FA and increased MD and RD were all recovered after MVD .In the not cure group ,there was no significant differences in all the DTI parameters before and af-ter MVD .Conclusions The changes of demyelination of ipsilateral trigeminal nerve are recovered to be normal in the patients with pain disappeared after MVD ;while the changes of demyelination of ipsilateral trigeminal nerve still existe in the patients with pain after MVD .The relationship between the changes of demyelination of trigeminal nerve and TN is closely related .