Trigeminal Neuralgia (TN), also known as Tic douloureux, is a painful twitch.
Trigeminal neuralgia (TN), also known as tic douloureux, is divided into two types: primary and secondary, and is characterized by recurrent episodes of transient paroxysmal severe pain in the trigeminal distribution of the face. Foreign epidemiological surveys have shown an incidence of about 5/100,000 population/year. Secondary trigeminal neuralgia has a clear cause, such as tumor, vascular lesion or skull base malformation, which compresses and stimulates the trigeminal nerve and causes facial pain, and needs to be treated for the primary lesion. There are various theories on the etiology of primary trigeminal neuralgia. The widely accepted one is the microvascular compression theory, in which some nerve fibers in the sensory afferent pathway of the trigeminal nerve undergo demyelinating lesions due to vascular compression, resulting in short-circuiting of the afferent nerve impulses and causing non-injurious sensory impulses to trigger an injurious pain response. In a section of the trigeminal nerve about 1 cm anterior and posterior to the pontine brain, myelinated afferent nerve fibers gradually change to unmyelinated nerve fibers. There is evidence that blood vessels passing through this area, especially tortuous arteries, can compress the trigeminal nerve into the pontine area and cause demyelinating changes in the nerve fibers, which is thought to be the main cause of trigeminal neuralgia. Other theories include the nucleus accumbens degeneration theory and the epileptiform central sensory discharge circuit theory.