RESUMEN
Trigeminal neuralgia is a cranial rhizopathy characterized by paroxysms of hyperactivity strictly limited to the anatomical distributions of the fifth cranial nerve. One of a documented cause is vascular cross-compression at the root entry zone of the fifth cranial nerve near the brain stem. The offending vessels are the superior cerebellar artery, anterior inferior cerebellar artery, small arteriole, vein only, and vertebrobasilar artery in order of frequency. When trigeminal neuralgia and hemifacial spasm occur together in the same patient in rare occasions, they are termed "tic convulsif" We have recently experienced three cases of trigeminal neurlgia caused by unusual offending vessels and one case of tic convulsif. They were treated by microvascular decompression using Teflon felt. Post-operative courses were uneventful and marked symptomatic improvement had been achieved.