Trigeminal neuralgia (TN or TGN), also called Fothergill disease, tic douloureux, trifacial neuralgia, is a long-term pain disorder that affects the trigeminal nerve,[6][1] the nerve responsible for sensation in the face and motor functions such as biting and chewing.

[1] The typical form results in episodes of severe, sudden, shock-like pain in one side of the face that lasts for seconds to a few minutes.

[5][1] It is estimated that trigeminal neuralgia affects around 0.03% to 0.3% of people around the world with a female over-representation around a 3:1 ratio between women and men.

It affects lifestyle as it can be triggered by common activities such as eating, talking, shaving and brushing teeth.

The attacks are said, by those affected, to feel like stabbing electric shocks, burning, sharp, pressing, crushing, exploding or shooting pain that becomes intractable.

[13] The severity of the pain makes it difficult to wash the face, shave, and perform good oral hygiene.

[16] In these instances there is also a more prolonged lower severity background pain that can be present for over 50% of the time and is described more as a burning or prickling, rather than a shock.

Herpes zoster oticus typically presents with inability to move many facial muscles, pain in the ear, taste loss on the front of the tongue, dry eyes and mouth, and a vesicular rash.

[18] The trigeminal nerve is a mixed cranial nerve responsible for sensory data such as tactition (pressure), thermoception (temperature), and nociception (pain) originating from the face above the jawline; it is also responsible for the motor function of the muscles of mastication, the muscles involved in chewing but not facial expression.

This type of injury may rarely be caused by an aneurysm (an outpouching of a blood vessel); by an AVM (arteriovenous malformation);[21] by a tumor; such as an arachnoid cyst or meningioma in the cerebellopontine angle;[22] or by a traumatic event, such as a car accident.

Chronic nerve entrapment results in demyelination primarily, with progressive axonal degeneration subsequently.

[4] It is, "therefore widely accepted that trigeminal neuralgia is associated with demyelination of axons in the Gasserian ganglion, the dorsal root, or both.

"[24] It has been suggested that this compression may be related to an aberrant branch of the superior cerebellar artery that lies on the trigeminal nerve.

Trigeminal neuralgia is diagnosed via the result of neurological and physical tests, as well as the individual's medical history.

[1] Magnetic resonance angiography can be used to detect vascular compression of the trigeminal nerve and refer patients to surgery.

[32] Even suspected TN patients who experience brief attacks of sharp pain have had their symptoms resolve after being treated for TMD.

[13] One quick test a dentist might perform is a conventional inferior dental local anesthetic block.

[citation needed] Microvascular decompression provides freedom from pain in about 75% of patients presenting with drug-resistant trigeminal neuralgia.