trigeminal neuralgia, a neurological condition of the trigeminal facial nerve, characterized by paroxysms of flashing, stablike pain radiating along the course of a branch of the nerve from the angle of the jaw. It is caused by degeneration of the nerve or by pressure on it. Any or all of the three branches of the nerve may be affected. Neuralgia of the first branch results in pain around the eyes and over the forehead; of the second branch, in pain in the upper lip, nose, and cheek; of the third branch, in pain on the side of the tongue and the lower lip. The momentary bursts of pain recur in clusters lasting many seconds. Paroxysmal episodes of the pains may last for hours. Also called prosopalgia, tic douloureux.
