[Trigeminal neuralgia: how often are trigeminal nerve-vessel contacts found by MRI in normal volunteers].

PURPOSE

To assess prospectively how often contacts are found between the trigeminal nerve and arteries or veins in the perimesencephalic cistern via MRI in normal volunteers.

MATERIALS AND METHODS

48 volunteers without a history of trigeminal neuralgia were examined prospectively (MRI at 1.5 T; T2-CISS sequence, coronal orientation, 0.9 mm slice thickness). Two radiologists decided by consensus whether there was a nerve-vessel contact in the perimesencephalic cistern.

RESULTS

In 27 % of the volunteers, no contact was found between the trigeminal nerve and regional vessels, while in 73 %, such a contact was present. In 61 % of the cases, the offending vessel was an artery, in 39 %, it was a vein. In 2 volunteers, a deformation of the nerve was noted.

CONCLUSION

Contrary to what has been suggested by retrospective studies, the majority of normal volunteers, if studied prospectively, do show a contact between the trigeminal nerve and local vessels. A close proximity between the nerve and regional vessels is thus normal and is not necessarily proof of a pathological nerve-vessel conflict.