Trigeminal neuralgia

Trigeminal neuralgia is a sudden, severe pain in the face. People describe it as sharp, shooting, or like an electric shock.

The pain usually comes in short attacks that last from a few seconds to about two minutes, and then stop just as abruptly. In the vast majority of cases it affects part or all of one side of the face, and it is most often felt in the lower part. Very occasionally it affects both sides of the face, but not normally at the same time.

Attacks can come regularly for days, weeks or months at a time. In severe cases, they may happen hundreds of times a day.

The pain can improve, or even go away altogether, for several months or years at a time. This is called a period of remission, though these periods tend to get shorter as time goes on. Some people then go on to develop a more continuous aching, throbbing and burning feeling, sometimes with the sharp attacks on top of it.

Attacks are typically brought on by anything that lightly touches the face, such as washing, eating and brushing the teeth. Wind can also trigger them (even a slight breeze or air conditioning), and so can movement of the face or head. Sometimes the pain comes without any trigger at all.

Living with trigeminal neuralgia can be very difficult. It can affect a person's quality of life in a big way, causing problems such as weight loss, isolation and depression.

See a doctor if you have facial pain that keeps coming back or won't go away. This matters most if ordinary painkillers such as paracetamol and ibuprofen don't help and a dentist has ruled out any problem with your teeth.

The doctor will ask about your symptoms and try to rule out other conditions that could be causing the pain. Diagnosing trigeminal neuralgia can be difficult, though, and it can take a few years before the diagnosis is confirmed.

In most cases, trigeminal neuralgia is caused by pressure on the trigeminal nerve. This is the largest nerve inside the skull, and it carries sensations of pain and touch from your face, teeth and mouth to your brain.

The pressure usually comes from a blood vessel lying close to the nerve and pressing on part of it inside the skull.

Rarely, trigeminal neuralgia happens because the nerve has been damaged by an underlying condition, such as multiple sclerosis (MS) or a tumour.

Trigeminal neuralgia is usually a long-term condition, and the periods of remission often get shorter over time. Still, most cases can be controlled to at least some degree with treatment.

The first treatment you're offered will usually be an anticonvulsant medicine called carbamazepine (it's normally used to treat epilepsy). For it to work, you need to take it several times a day. The dose is raised gradually over a few days or weeks, so that enough of the medicine can build up in your bloodstream.

Unless your pain starts to fade or goes away altogether, the medicine is usually continued for as long as is necessary, sometimes for many years. If you're entering a period of remission and the pain goes away, stopping the medicine should always be done slowly, over days or weeks, unless a doctor advises you otherwise.

Carbamazepine wasn't originally made to treat pain, but it can help relieve nerve pain. It slows down electrical impulses in the nerves and reduces their ability to transmit pain messages.

If this medicine doesn't work, isn't suitable for you or causes too many side effects, you may be referred to a specialist to discuss other medicines or surgical procedures that may help.

There are a number of minor surgical procedures that can be used to treat trigeminal neuralgia, usually by damaging the nerve so it stops sending pain signals. But these are generally only effective for a few years.

Or your specialist may recommend surgery to open up your skull and move away any blood vessels pressing on the trigeminal nerve. Research suggests this operation gives the best results for long-term pain relief. But it is a major operation and carries a risk of potentially serious complications, such as hearing loss, facial numbness or, very rarely, a stroke.

The main symptom of trigeminal neuralgia is a sudden attack of severe, sharp, shooting pain in the face. Each attack lasts anywhere from a few seconds to about two minutes.

People often describe the pain as excruciating, like an electric shock. An attack can be so bad that you can't do anything while it lasts, and sometimes the pain can bring you to your knees.

Trigeminal neuralgia usually affects only one side of your face. In rare cases it can affect both sides, though not at the same time. The pain can be in the teeth, the lower jaw, the upper jaw or the cheek, and less commonly in the forehead or the eye.

You may feel an attack coming, but most of the time they arrive without warning.

Once the main, severe pain has eased, you may be left with a slight ache or a burning feeling. Some people also have a constant throbbing, aching or burning sensation between attacks.

The pain can come regularly for days, weeks or months at a time. It may then disappear completely and not return for several months or years (this period is called "remission"). In severe cases, though, attacks may happen hundreds of times a day, and there may be no periods of remission at all.

Attacks of trigeminal neuralgia can be set off by certain actions or movements, such as:

• talking
• smiling
• chewing
• brushing your teeth
• washing your face
• a light touch
• shaving or putting on make-up
• swallowing
• kissing
• a cool breeze or air conditioning
• head movements
• vibrations, such as walking or a car journey

But the pain can also come on by itself, with no trigger at all.

Living with trigeminal neuralgia can be extremely difficult, and it can affect your quality of life a great deal.

You may feel like avoiding things such as washing, shaving or eating, because they can set off the pain. The fear of pain may also make you stay away from social activities. But try to live as normally as you can, and be aware that becoming undernourished or dehydrated can make the pain far worse.

Having repeated episodes of pain puts a heavy strain on you emotionally, and this can lead to psychological problems such as depression. During periods of extreme pain, some people may even consider suicide. Even when you're pain-free, you may live in fear of the pain coming back.

You should see a doctor if you have facial pain that comes often or won't go away. This matters even more if ordinary painkillers such as paracetamol and ibuprofen don't help, and a dentist has already ruled out any problem with your teeth.

The doctor will ask about your symptoms and try to rule out other conditions that could be causing the pain. Trigeminal neuralgia can be hard to diagnose, so try to describe your symptoms as accurately and in as much detail as you can.

Doctors don't know the exact cause of trigeminal neuralgia. It's often thought to come from pressure on the trigeminal nerve, or from an underlying condition that affects this nerve.

The trigeminal nerve (also called the fifth cranial nerve) is the largest nerve inside the skull. You have two of them, one on each side of your face. Small branches from different parts of the face join up into three major nerve branches. These are:

• the upper branch (ophthalmic), which carries sensory information from the skin above the eye, forehead and front of the head
• the middle branch (maxillary), which carries sensory information from the skin through the cheek, side of the nose, upper jaw, teeth and gums
• the lower branch (mandibular), which carries sensory information from the skin through the lower jaw, teeth and gums

These branches enter the skull by three different routes. They then join together in what is called the Gasserian ganglion, before connecting to the brainstem in the part of the skull called the posterior fossa.

Trigeminal neuralgia can involve one or more branches of the trigeminal nerve. The maxillary and mandibular branches are affected most often, and the ophthalmic branch is the least commonly affected.

Studies suggest that in up to 95% of cases, trigeminal neuralgia is caused by pressure on the trigeminal nerve. The pressure happens close to where the nerve enters the brain stem (the lowest part of the brain, which merges with the spinal cord), just past the Gasserian ganglion.

In most people, an artery or a vein is pressing on the nerve. Nobody knows why this happens.

It's also unclear exactly why the pressure leads to painful attacks, since not everyone with a compressed trigeminal nerve feels pain. One possibility is that in some people the pressure wears away the nerve's protective outer layer, called the myelin sheath. This may let uncontrollable pain signals travel along the nerve.

But this doesn't fully explain two things. One is why periods of remission (periods without symptoms) can occur. The other is why pain relief is immediate after a successful operation to move the blood vessels away from the nerve.

The trigeminal nerve can also become compressed or damaged for other reasons, including:

• a tumour (a growth or lump)
• a cyst (a fluid-filled sac)
• arteriovenous malformation (an abnormal tangle of arteries and veins)
• multiple sclerosis (MS), a long-term condition that affects the central nervous system (the brain and spinal cord)

The pain of trigeminal neuralgia is often felt in the jaw, teeth or gums, so many people go to their dentist first, not their doctor.

If you do see your dentist, they will ask about your symptoms. They will also look into your facial pain with a dental X-ray and other checks, to rule out more common causes such as a dental infection or a cracked tooth.

If the dentist can't find a cause, you should not go through unnecessary treatment such as a root canal filling or an extraction, even if you feel sure it's a tooth problem. And if your dentist finds nothing wrong, don't try to persuade them to remove a particular tooth, because this will not solve the problem.

A dentist can often make the diagnosis of trigeminal neuralgia. But if you have already seen your dentist and they have not found an obvious cause for your pain, visit your doctor.

There's no specific test for trigeminal neuralgia, so the diagnosis mostly rests on your symptoms and how you describe the pain.

If you've had facial pain, the doctor will ask you about it. They'll want to know how often the attacks come, how long each one lasts and which parts of your face are affected. The more detail you can give about your pain, the better.

The doctor will also think about other possible causes for the pain. They may examine your head and jaw as well, to find out which parts are painful.

Part of diagnosing trigeminal neuralgia is making sure the pain isn't coming from something else, because other conditions can also cause facial pain.

By asking about your symptoms and examining you, your doctor may be able to rule out conditions such as:

• migraine
• joint pain in the lower jaw
• giant cell arteritis (temporal arteritis), a condition in which medium and large arteries in the head and neck become inflamed and cause pain in the jaw and temples
• a possible injury to one of the facial nerves

Your medical, personal and family history will also need to be taken into account when working out what could be causing your pain.

For example, trigeminal neuralgia is less likely if you are under 40 years old. Multiple sclerosis (MS) may be more likely if you have a family history of the condition, or if you have some other form of it. Even so, trigeminal neuralgia is very unlikely to be the first symptom of MS.

If your doctor isn't sure about your diagnosis, or if your symptoms are unusual, you may be sent for a magnetic resonance imaging (MRI) scan of your head.

An MRI scan uses strong magnetic fields and radio waves to make detailed pictures of the inside of your head. It can help find possible causes of your facial pain, such as sinusitis (inflammation of the lining of the sinuses), tumours on one of the facial nerves, or nerve damage caused by MS.

An MRI can also sometimes show whether a blood vessel in your head is pressing on one of the trigeminal nerves. This is one of the main causes of trigeminal neuralgia. But very sophisticated MRI scans may be needed to show it accurately, and even then it may not be especially helpful, because not everyone with a compressed trigeminal nerve has trigeminal neuralgia.

Several treatments can give some relief from the pain of trigeminal neuralgia, and it also helps to work out what sets the pain off and then avoid those triggers.

Most people with trigeminal neuralgia are given medicine to control the pain. If the medicine doesn't work, or it causes too many side effects, doctors may consider surgery as a longer-term option.

Several things can set off the painful attacks of trigeminal neuralgia, or make them worse. So alongside your medical treatment, it may help to stay away from these triggers where you can.

If wind or even a draught in a room brings on your pain, try not to sit near open windows or the air conditioning. In windy weather, a scarf wrapped around your face may help. A transparent dome-shaped umbrella can also shield your face from the weather.

Hot, spicy or cold food and drink can trigger pain too, so avoiding them can help. If you drink something warm or cold, a straw may keep the liquid away from the painful areas of your mouth. You still need to eat nourishing meals, though. If chewing is difficult, you could try mushy foods or liquidise your meals.

Some foods seem to trigger attacks in certain people, so you may want to think about avoiding things like caffeine, citrus fruits and bananas.

Ordinary painkillers such as paracetamol don't work for trigeminal neuralgia. So your doctor will normally prescribe a different kind of medicine, often an anticonvulsant (these are usually used to treat epilepsy), to help control the pain.

Anticonvulsants were not originally made to treat pain. But they can ease nerve pain because they slow down the electrical impulses in the nerves and make them less able to carry pain signals.

You need to take them regularly, not just when an attack of pain comes. You can stop them when the episodes of pain end and you are in remission. Unless your doctor or specialist tells you otherwise, build up the dose slowly, and bring it down again gradually over a few weeks. Taking too much too soon, or stopping the medicine too quickly, can cause serious problems.

At first, your doctor will probably prescribe an anticonvulsant called carbamazepine. A number of other medicines are available if carbamazepine doesn't work or isn't suitable for you.

The anticonvulsant carbamazepine is the only medicine licensed for treating trigeminal neuralgia in the UK. It can work very well at first, but it may become less effective over time.

You will usually start with a low dose, taken once or twice a day. The dose is then raised slowly, up to four times a day, until the pain is relieved satisfactorily.

Carbamazepine often causes side effects, and for some people these make it hard to keep taking it. They include:

• tiredness and sleepiness
• dizziness (lightheadedness)
• difficulty concentrating and memory problems
• confusion
• feeling unsteady on your feet
• feeling sick and vomiting
• double vision
• a reduced number of infection-fighting white blood cells (leukopenia)
• allergic skin reactions, such as urticaria (hives)

If any side effect lasts or becomes troublesome while you are taking carbamazepine, speak to your doctor. Do this especially for allergic skin reactions, as these could be dangerous.

Carbamazepine has also been linked to a number of less common but more serious side effects, including thoughts of self-harm or suicide. If you have any suicidal feelings, report them to your doctor immediately.

Carbamazepine may stop working over time. If that happens, or if the side effects become significant, you should be referred to a specialist who can consider other medicines or procedures.

You may be referred to one of several specialists for further treatment. These include neurologists who specialise in headaches, neurosurgeons and pain medicine specialists (for example, at a pain clinic).

Besides carbamazepine, a number of other medicines have been used to treat trigeminal neuralgia, including:

• oxcarbazepine
• lamotrigine
• gabapentin
• pregabalin
• baclofen

None of these is specifically licensed for treating trigeminal neuralgia. This means they haven't been through rigorous clinical trials to find out whether they are effective and safe for the condition.

The reason is largely that trigeminal neuralgia is a rare condition, and trials are hard to carry out when the pain is so severe. Giving some people an inactive "dummy" medicine (a placebo) to compare against would be unethical and impractical.

Even so, many specialists will prescribe an unlicensed medicine if they think it is likely to work and the benefits outweigh the risks.

If your specialist is thinking of prescribing an unlicensed medicine for trigeminal neuralgia, they should tell you it is unlicensed and talk through the possible risks and benefits with you.

With most of these medicines, the side effects can be quite hard to cope with at first. Not everyone gets them, but if you do, try to persevere. They tend to ease with time, or at least until the next increase in dose, when you may need another period of adjustment. Talk to your doctor if you find the side effects unbearable.

If your medicine doesn't control the pain well enough, or it causes side effects that keep bothering you, your doctor may refer you to a specialist. The specialist can talk with you about the surgical and non-surgical options that could relieve the pain of trigeminal neuralgia.

Several procedures have been used to treat trigeminal neuralgia, so you will need to go through the possible benefits and risks of each one with your specialist before you decide. It's wise to be as well informed as you can, and to choose what is right for you as a person.

There is no guarantee that any one of these procedures will work for you. But once a procedure has worked, you won't need your pain medicine unless the pain comes back. If one procedure doesn't work, you can try another, or you can stay on your medicine for a while or for good.

Some of the procedures used for people with trigeminal neuralgia are outlined below.

There are several procedures that can ease trigeminal neuralgia pain, at least for a while. A needle or thin tube is put through the cheek and into the trigeminal nerve inside the skull.

These are called "percutaneous" (through the skin) procedures. X-rays guide the needle or tube to the right place, and you are either heavily sedated with medicine or under a general anaesthetic (where you are asleep).

The percutaneous procedures used to treat trigeminal neuralgia include:

• glycerol injections, where a medicine called glycerol is injected around the Gasserian ganglion (the place where the three main branches of the trigeminal nerve join together)
• radiofrequency lesioning, where a needle is used to apply heat directly to the Gasserian ganglion
• balloon compression, where a tiny balloon is passed along a thin tube inserted through the cheek and is inflated around the Gasserian ganglion to squeeze it, and then the balloon is removed

These procedures work by deliberately injuring or damaging the trigeminal nerve. This is thought to disrupt the pain signals travelling along it. You can usually go home the same day after your treatment.

All of these procedures are similarly effective at relieving the pain. Each one can cause complications, though, and these vary with the procedure and from person to person. The pain relief usually lasts only a few years, and sometimes only a few months. Sometimes the procedures do not work at all.

The major side effect is numbness in part or all of one side of the face. It can range from very numb to just pins and needles. The feeling is often similar to what you get after an injection at the dentist, and it can be permanent. Very rarely, people get a mix of numbness and continuous pain called anesthesia dolorosa, which is virtually untreatable.

The procedures also carry a risk of other short- and long-term side effects and complications, including bleeding, facial bruising, eye problems and problems moving the facial muscles.

Stereotactic radiosurgery is another way to relieve trigeminal neuralgia pain by damaging the trigeminal nerve, and nothing has to be inserted through the skin. It's a fairly new treatment. A concentrated beam of radiation is used to deliberately damage the nerve at the point where it enters the brainstem.

You don't need a general anaesthetic for stereotactic radiosurgery, and no cuts (incisions) are made in your cheek.

A metal frame is attached to your head with four pins placed around your scalp (a local anaesthetic numbs the areas where the pins go in). Your head, with the frame still attached, is then held in a large machine for an hour or two while the radiation is given, and this may make you feel claustrophobic. Afterwards the frame and pins are removed, and you can go home after a short rest.

The treatment can take a few weeks, or sometimes many months, to take effect. For some people it then brings pain relief for several months or years. Studies of this treatment have shown similar results to the other procedures mentioned above.

The most common complications are facial numbness and pins and needles (paraesthesia) in the face. This can be permanent and, in some cases, very troublesome.

Microvascular decompression (MVD) is an operation that can relieve trigeminal neuralgia pain without deliberately damaging the trigeminal nerve. What it does instead is take the pressure off the nerve, pressure that comes from blood vessels touching it or wrapped around it.

This is a major operation. The skull has to be opened, and a neurosurgeon carries it out under general anaesthetic.

The surgeon makes a cut in your scalp, behind your ear, and removes a small circular piece of skull bone. They then either remove the blood vessel(s) or move them away, and keep them separated from the trigeminal nerve using an artificial pad or a sling made from nearby tissue.

For many people, this surgery eases the pain of trigeminal neuralgia or stops it completely. It gives the longest lasting relief, and some studies suggest the pain comes back in only about 30% of cases within 10-20 years of the operation. At present, it is the closest thing to a cure for trigeminal neuralgia.

But it is an invasive procedure, and it carries a risk of serious complications, such as facial numbness, hearing loss, stroke and even death (in around 1 in every 200 cases).