[The role of MR angiography in predicting operative results of microvascular decompression in patients with trigeminal neuralgia].

INTRODUCTION AND OBJECTIVES: The results of medium-term outcome of microvascular decompression (MVD) for trigeminal neuralgia are presented. The authors compare the preoperative 3-dimension magnetic resonance angiography (MRA) results with the surgical findings during MVD. Information, provided by MRA, are evaluated regarding to the prognostic significance in typical TN, atypical TN and persistent idiopathic facial pain (PIFP). The significance of clinical symptoms and the type of neurovascular compression (NC) are investigated in respect of the postoperative success and recurrent symptoms.

METHODS AND RESULTS: MRA was performed in 310 consecutive patients with TN and PIFP. The MRA image was positive in 179 (58%) of the 310 cases. 68.2% of the typical TN group, 49.2% of the atypical TN group and 3.2% of the PIFP group were positive. MVD was performed in 116 of the MRA positive cases. Four years following the MVD, 69% of the patients gave an excellent and 23% a good result. The surgical findings corresponded with the MRA images. NC could be ruled out in the background of PIFP. The rate of recurrent symptoms following MVD is 21% in the typical TN group while it is 41% in the atypical TN group. The pure venous compression showed 57% pain-recurrence rate following MVD.

CONCLUSIONS: The clinical symptoms and preoperative MRA carry considerable information, which can predict the outcome of the MVD and the rate of recurrent symptoms. Atypical TN and venous compression are bad prognostic factors.