Trigeminal Neuralgia

What is the trigeminal nerve?

The trigeminal nerve (also called the fifth cranial nerve) is one of the main nerves of the face. There is one on each side. It comes through the skull from the brain, in front of the ear. It is called trigeminal as it splits into three main branches. Each branch divides into many smaller nerves.

The nerves from the first branch go to your scalp, forehead and the area around your eye. The nerves from second branch go to the area around your cheek. The nerves from the third branch go to the area around your jaw.

The branches of the trigeminal nerve take sensations of touch and pain to the brain from all areas of your face, teeth and mouth. The trigeminal nerve also controls the muscles used in chewing, and the production of saliva and tears.

Neuralgia means pain coming from a nerve. In TN you have sudden, and usually severe, pains coming from one or more branches of the trigeminal nerve. The second and third branches are the most commonly affected. Therefore, the pain is usually around your cheek, jaw or both. The first branch is less commonly affected so pain over your forehead and around your eye is less common. It usually affects one side of your face. Rarely, both sides are affected.

The pain is stabbing ("like electric shocks"), piercing, sharp, or knife like. It usually lasts a few seconds but can last up to two minutes. The pain can be so sudden and severe that you may jerk or grimace with pain. The time between each pain may be minutes, hours, or days. Sometimes several pains repeat in quick succession. After an attack of pain you may have a dull ache and tenderness over the affected area which soon eases. However, constant pain in the face is not a feature of TN.

You may have 'trigger points' on your face where touch or even a draught of air can trigger a pain. These are often around the nose and mouth. Because of these, some people do not wash or shave for fear of triggering a pain. Eating, talking, smoking, brushing teeth, or swallowing may also trigger a pain.

Between attacks of pain, there are no other symptoms, the nerve works normally, and a doctors examination would find no abnormality.

What causes trigeminal neuralgia?

In many cases it is thought that blood vessels press on the root of the nerve where the nerves comes out from the brain. However, it is not known why blood vessels should start to press on the trigeminal nerve in later life. Rarely, TN is a symptom of multiple sclerosis. (But note: most people with TN do not have multiple sclerosis.) In some people the cause is not known.

Who gets trigeminal neuralgia?

TN is uncommon. About 5 people in 100,000 develop it each year. It mainly affects older people, and it usually starts in your 60s or 70s. It is rare in younger adults. Women are more commonly affected than men.

Do I need any tests?

There is no test that can confirm TN. However, no test is needed as the diagnosis is made from the typical symptoms.

How does trigeminal neuralgia progress?

A first attack of pain usually occurs 'out of the blue' for no apparent reason. Further pains then come and go. The frequency of pains varies from up to a hundred times a day, to just an occasional pain every now and then. This first 'bout' or 'episode' of pains may last days, weeks, or months, and then typically the pains stop for a while.

Further bouts of pain usually develop sometime in the future. However, several months or even years may pass between bouts of pains. It is impossible to predict when the next bout of pains will occur, or how often the bouts will recur. Bouts of pains tend to become more frequent as you become older.

Are there any complications?

The pain itself can be severe and distressing. If left untreated, this may make you depressed or anxious. You may neglect to clean your teeth, or not eat for fear of triggering the pain. This can lead to weight loss and poor mouth hygiene. However, there are no complications of the trigeminal nerve itself or of the brain.

What are the treatments for trigeminal neuralgia?

Carbamazepine is the usual treatment
Carbamazepine is classed as an anticonvulsant medicine. It is normally used to treat epilepsy. TN is not epilepsy. However, the effect of carbamazepine is to quieten nerve impulses and works well for TN. Carbamazepine eases symptoms of TN within 24 hours in about 7 in 10 cases, and within two days in over 9 in 10 cases. A low dose is started and built up gradually until a dose is reached that stops the pains. You should then take it regularly to prevent pains from returning. The dose of carbamazepine needed to control the pains varies from person to person.

It is common to take carbamazepine until about a month after the pains have stopped. The dose may then be reduced gradually, and stopped if possible. After this there is often a period when pains do not occur for some time (remission). However, the pains are likely to return sometime in the future. Treatment can then be restarted. Some people find that carbamazepine works well at first but less well over the years.

Side-effects occur in about 1 in 10 people who take carbamazepine. Side-effects are more likely if higher doses are needed, but even low doses cause side-effects in some people. Read the medicine packet leaflet for a full list of possible side-effects. The most common include: drowsiness, feeling sick, tiredness, and dizziness. Quite often these are only temporary, so it is worth persisting with the medicine if the pains ease and side-effects are not too bad.

Rarely, carbamazepine can cause serious blood or liver problems. Therefore, tell your doctor if you develop any of the following whilst taking this medicine: fever, sore throat, ulcers in your mouth, easy bruising, or a rash - particularly if the rash is of small purple spots. (These symptoms may be due to blood problems caused by medication.)

Other medicines
Other medicines may be tried if carbamazepine does not work well or causes bad side-effects. These include other anticonvulsants such as gabapentin, and amitriptyline. A combination of two medicines is occasionally tried if one alone does not help.

Normal painkillers such as paracetamol or codeine do not work for TN.

Surgery
An operation is an option if medication does not work or causes bad side-effects. Basically, the aim of surgery is to ease any pressure at the root of the trigeminal nerve (which is often caused by pressure from nearby blood vessels). There are various techniques, each with their pros and cons. The advice from a specialist is essential. The chance of a cure from surgery is very good, but there is a small risk that surgery can affect normal sensation to parts of your face or eye.

Further help and advice

Trigeminal Neuralgia Association UK
PO Box 413, Bromley, BR2 9XS
Web: www.tna.org.uk

© EMIS and PIP 2006   Updated: July 2006   PRODIGY Validated