Trigeminal Neuralgia due to Compression of the Trigeminal Root by a Basilar Artery Trunk

Report of 45 Cases

Abstract

The authors report their personal experience of the surgical treatment of trigeminal neuralgia with special reference to the results of microvascular decompression (MVD) in cases with basilar artery (BA) trunk compression. In the past 7 years, 730 patients with trigeminal neuralgia were surgically treated in their institute. These included 595 patients with genuine tic douloureux (Group 1), 42 with atypical trigeminal neuralgia (Group II), and 8 with atypical facial pain (Group III). In the Group I tic patients, typical neurovascular compression was observed in 582 cases (97.8%). In this series of 582 cases, 45 patients had vascular compressions by the elongated BA. Among these, simple BA compression was rare (4 cases, 8.9%) and the majority had multiple vessel compression along with anterior inferior cerebellar artery, superior cerebellar artery, petrosal vein, vertebral artery, or a combination of these vessels. Clinical features of these 45 cases, operative technique to mobilize tortuous and enlarged BA, and the surgical results are presented. The importance of enhanced computed tomography scan in predicting BA compression preoperatively is stressed. The vertebrobasilar artery was visualized as a linear enhancement crossing the prepontine cistern in all cases of BA compression. The postoperative follow-up period ranged from 6 to 50 months (mean: 19 months). Complete pain relief was obtained in 43 cases (95.6%). In 2 cases (4.4%), tic pain recurred at 2 and 3 months postoperatively. Because of the tremendous tortuousity, hypertrophy, and sclerosis of the BA, it was extremely difficult in all cases to transpose the BA sufficiently off the nerve root. As many as 23 cases (51%) had a total of 41 neurological symptoms and signs after surgery, although most of them were only temporary and disappeared within 1 to 3 months. The most frequent neurological complications were facial hypesthesia and diplopia due to the fourth or sixth cranial nerve paresis. There were six permanent neurological deficits in 5 patients (11%).
The authors are convinced that MVD, though it involves some technical difficulties, should be attempted, and that the procedure will lead to a satisfactory result.