Trigeminal neuralgia: compression of the trigeminal nerve by an elongated and dilated basilar artery.

A patient with trigeminal neuralgia caused by direct compression by an elongated basilar artery of the 5th nerve at the zone of entry of its sensory root into the pons is presented. Rhizotomy of the portio major is a treatment of choice in such a case instead of simple microsurgical decompression. The elongated basilar artery is very firm and not readily movable with manipulation.