What is Trigeminal neuralgia?
Trigeminal neuralgia (tic douloureux) is a very painful disorder of the fifth cranial nerve (trigeminal nerve) located in the face. Because the sudden, sharp pain often causes the individual to wince, the condition is also known as tic douloureux (in French) or painful twitch.
Trigeminal neuralgia occurs in two different forms. The typical (idiopathic) form occurs almost exclusively in persons over the age of 50. It affects women more frequently than men in a 3:1 ratio. The symptomatic form can occur in any age group. It may be caused by a tumor of the trigeminal nerve or pressure on the nerve root by a blood vessel (vascular anomaly). Trigeminal neuralgia has been long recognized as a disease, being described in medical writings from the first century AD.
How is it diagnosed?
History: Individuals will report pain affecting one side of the face that comes in lightning-like stabs that spread from the angle of the jaw. A classic symptom of this disorder is that the pain can be initiated by trigger points on the face that are stimulated by touch. Even such innocuous activities like washing the face, brushing the teeth, shaving, eating, drinking, or even talking can set off a painful attack.
It lasts only seconds, but the pain is so intense that the individual is incapacitated for the duration of the attack. Attacks occur in bouts that may last for weeks at a time. Then, there are pain-free intervals also lasting weeks/months. As time goes on, the pain-free interval between attacks becomes shorter.
Physical exam: A thorough examination of the teeth, jaw, and sinuses is performed to exclude other causes of the pain. The neurological exam will include an assessment of the pain pathway in association with trigeminal nerve branch. The trigeminal nerve divides into three main branches. If it is the first branch that is affected, shock-like pain is felt along the eye and back over the forehead. The middle nerve branch sends pain along the upper lip, nose, and cheek under the eye. Pain from the third branch is felt in the lower lip and outer edge of the tongue. If the individual is examined during an episode of pain, involuntary twitching of the muscles of the face along the nerve branch can be seen.
Tests: MRI may be done to exclude the possibility of a space-occupying lesion affecting the trigeminal nerve. Cerebral angiograms can outline vascular anomalies.
How is trigeminal neuralgia treated?
- The initial treatment is with certain anticonvulsant drugs that suppress the pain and may shorten attacks or encourage remission. However, some people become resistant to the drug or are unable to tolerate a dose high enough to relieve the pain.
- When medications lose their effectiveness surgical intervention is an alternative. The least invasive procedures are done with a needle or probe and involve injecting the nerve with alcohol providing temporary relief from symptoms, but pain may return as the nerve regenerates.
- The next steps would involve attempts to destroy the nerve root using high-frequency currents (thermocoagulation), removing part of the nerve (percutaneous ablation), or by injecting the nerve root with a substance such as alcohol.
- If other treatments fail, neurosurgery can be done to attempt to relieve pressure on the nerve (microvascular decompression) or to do nerve sectioning (partial rhizotomy).
Tegretol (Carbamazepine), Trileptal (Oxcarbazepine)
What might complicate it?
The drugs used to control the disease must be carefully monitored as they can have side effects on the liver and bone marrow.
Medication frequently provides relief from symptoms. The outcome of the various surgical approaches is unpredictable, but the pain is so great that the individual must be informed of any operations that may provide relief. Individuals who have frequent and ongoing attacks may be significantly disabled by the condition.
Migraine headaches and infection of the maxillary sinus can mimic the pain to a degree, but trigeminal neuralgia has rather classic symptoms that are hard to confuse with other disorders. When the typical symptoms of this disorder are experienced in young adults, or if it affects both sides of the face, it should raise the suspicion of multiple sclerosis.
Neurologist and neurosurgeon.
Last updated 6 April 2018