Trigeminal neuralgia is a sudden, severe facial pain, described as sharp, shooting or like an electric shock.
It usually occurs in sudden short attacks lasting from a few seconds to about two minutes, which stop just as abruptly.
In the vast majority of cases it affects part or all of one side of the face, with the pain most commonly felt in the lower part of the face. Very occasionally it affects both sides of the face, but not normally at the same time.
People with the condition may experience attacks of pain regularly for days, weeks or months at a time. In severe cases, attacks may occur hundreds of times a day.
It's possible for the pain to improve or even disappear altogether for several months or years at a time (known as a period of remission), although these periods of remission tend to get shorter with time. Some people may then go on to develop a more continuous aching, throbbing and burning sensation, sometimes accompanied by the sharp attacks.
Typically, the attacks of pain are brought on by activities that involve lightly touching the face, such as washing, eating and brushing the teeth, but they can also be triggered by wind (even a slight breeze or air conditioning) or movement of the face or head. Sometimes, the pain can occur without any trigger whatsoever.
Living with trigeminal neuralgia can be very difficult and it can have a significant impact on a person's quality of life, resulting in problems such as weight loss, isolation and depression.
When to seek medical advice
You should see your GP if you experience frequent or persistent facial pain, particularly if standard painkillers such as paracetamol andibuprofen do not help and a dentist has ruled out any dental causes.
Your GP will try to identify the problem by asking about your symptoms and ruling out conditions that could be responsible for your pain.
However, diagnosing trigeminal neuralgia can be difficult, and it can take a few years for a diagnosis to be confirmed.
What causes trigeminal neuralgia?
In the vast majority of cases, trigeminal neuralgia is caused by compression of the trigeminal nerve. This is the largest nerve inside the skull, which transmits sensations of pain and touch from your face, teeth and mouth to your brain.
This compression is usually caused by a nearby blood vessel pressing on part of the nerve inside the skull.
In rare cases, trigeminal neuralgia can occur as a result of damage to the trigeminal nerve, caused by an underlying condition such as multiple sclerosis (MS) or a tumour.
Who is affected
It's not clear exactly how many people are affected by trigeminal neuralgia, but the condition is thought to be rare.
Some studies have suggested that around 27 in every 100,000 people are diagnosed with the condition in the UK each year, although this figure is probably too high as the condition tends to be over-diagnosed by doctors. Other estimates have suggested that there are about 6,500 new cases diagnosed each year in the UK.
The condition affects women more often than men and is rare in people under the age of 40, although it can occur in younger people. Most cases are first seen in people between the ages of 50 and 60.
How trigeminal neuralgia is treated
Trigeminal neuralgia is usually a long-term condition, and the periods of remission often get shorter over time. However, most cases can be controlled to at least some degree with treatment.
The first treatment offered will usually be with an anticonvulsant medication (usually used to treat epilepsy) called carbamazepine. To be effective, this medication needs to be taken several times a day, with the dose gradually increased over the course of a few days or weeks so that high enough levels of the medication can build up in your bloodstream.
Unless your pain starts to diminish or disappears altogether, the medication is usually continued for as long as is necessary, sometimes for many years. If you are entering a period of remission and your pain goes away, stopping the medication should always be done slowly over days or weeks, unless you are advised otherwise by a doctor.
Carbamazepine was not originally designed to treat pain, but it can help relieve nerve pain by slowing down electrical impulses in the nerves and reducing their ability to transmit pain messages.
If this medication is ineffective, unsuitable or causes too many side effects, you may be referred to a specialist to discuss alternative medications 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 to stop it sending pain signals – but these are generally only effective for a few years.
Alternatively, your specialist may recommend having surgery to open up your skull and move away any blood vessels compressing the trigeminal nerve. Research suggests this operation offers the best results in terms of 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.
This article focuses on trigeminal neuralgia, a rare type of neuralgia most commonly seen in people between the ages of 50 and 60.
Postherpetic neuralgia is a more common type of neuralgia that usually develops after a previous shingles infection.
Symptoms of trigeminal neuralgia
The main symptom of trigeminal neuralgia is sudden attacks of severe, sharp and shooting facial pain that last from a few seconds to about two minutes.
The pain is often described as an excruciating sensation, similar to an electric shock. The attacks can be so severe that you are unable to do anything during them, and the pain can sometimes bring you to your knees.
Trigeminal neuralgia usually only affects one side of your face. In rare cases it can affect both sides, although not at the same time. The pain can be in the teeth, the lower jaw, upper jaw, cheek and, less commonly, in the forehead or the eye.
You may feel aware of an impending attack of pain, though these usually come unexpectedly.
After the main, severe pain has subsided, you may experience a slight ache or burning feeling. There may also be a constant throbbing, aching or burning sensation between attacks.
You may have episodes of pain lasting regularly for days, weeks or months at a time. It is possible for the pain to then disappear completely and not recur for several months or years (a period known as "remission"). However, in severe cases, attacks may occur hundreds of times a day, and there may be no periods of remission.
Attacks of trigeminal neuralgia can be triggered by certain actions or movements, such as:
brushing your teeth
washing your face
a light touch
shaving or putting on make-up
a cool breeze or air conditioning
vibrations, such as walking or a car journey
However, pain can occur spontaneously with no triggers whatsoever.
Living with trigeminal neuralgia can be extremely difficult, and your quality of life can be significantly affected.
You may feel like avoiding activities such as washing, shaving or eating to avoid triggering pain, and the fear of pain may mean you avoid social activities. However, it's important to try to live a normal life, and be aware that becoming undernourished or dehydrated can make the pain far worse.
The emotional strain of living with repeated episodes of pain can lead to psychological problems, such as depression. During periods of extreme pain, some people may even consider suicide. Even when pain-free, you may live in fear of the pain returning.
When to see your GP
You should see your GP if you experience frequent or persistent facial pain, particularly if standard painkillers such as paracetamol andibuprofen do not help and a dentist has ruled out any dental causes.
Your GP will try to identify the problem by asking about your symptoms and ruling out conditions that could be responsible for your pain. Trigeminal neuralgia can be a difficult condition to diagnose, so it’s important to try to describe your symptoms as accurately and in as much detail as possible.
Causes of trigeminal neuralgia
Although the exact cause is not known, trigeminal neuralgia is often thought to be caused by compression of the trigeminal nerve or an underlying condition affecting this nerve.
The trigeminal nerve
The trigeminal nerve (also called the fifth cranial nerve) is the largest nerve inside the skull. You have two trigeminal nerves, one in each side of your face. Small branches from different parts of the face join into three major nerve branches. These are:
the upper branch (ophthalmic) – which carries sensory information from the skinabove 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 through three different routes and 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.
Pressure on the trigeminal nerve
Evidence suggests that in up to 95% of cases, the cause of trigeminal neuralgia is pressure on the trigeminal nerve close to where it enters the brain stem (the lowest part of the brain that merges with the spinal cord), past the Gasserian ganglion.
In most cases, this pressure seems to be caused by an artery or vein compressing the trigeminal nerve, although it's not known why this happens.
It's also not clear exactly why this pressure can cause painful attacks, as not everyone with a compressed trigeminal nerve will experience pain. It may be that, in some people, the pressure on the nerve wears away its protective outer layer called the myelin sheath, which may cause uncontrollable pain signals to travel along the nerve.
However, this does not fully explain why periods of remission (periods without symptoms) can occur and why pain relief is immediate after a successful operation to move the blood vessels away from the nerve.
Other underlying causes
Other reasons why the trigeminal nerve can become compressed or damaged include:
a tumour (a growth or lump)
a cyst (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)
Diagnosing trigeminal neuralgia
As the pain caused by trigeminal neuralgia is often felt in the jaw, teeth or gums, it is common for people to visit their dentist initially, rather than their GP.
If you visit your dentist, they will ask you questions about your symptoms and investigate your facial pain using a dental X-ray and other means to look for other more common causes, such as a dental infection or cracked tooth.
If the dentist cannot find a cause, it is important not to undergo unnecessary treatment such as a root canal filling or an extraction, even though you may be convinced that it is a tooth problem. If your dentist cant find anything wrong, do not try to persuade them to remove a particular tooth, as this will not solve the problem.
Often, the diagnosis of trigeminal neuralgia is made by a dentist, but if you have already seen your dentist and they have not been able to find an obvious cause of your pain, visit your GP.
Seeing your GP
There is no specific test for trigeminal neuralgia, so a diagnosis is largely based on your symptoms and your description of the pain.
If you have experienced facial pain, your GP will ask you questions about your symptoms, such as how often they occur, how long the pain attacks last and which areas of your face are affected. The more details about your pain you can provide, the better.
Your GP will consider other possible causes of your pain and may also examine your head and jaw to identify which parts are painful.
Ruling out other conditions
An important part of the process of diagnosing trigeminal neuralgia involves ruling out other conditions that can also cause facial pain.
By asking about your symptoms and carrying out an examination, your GP may be able to rule out other conditions, such as:
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 consideration when determining possible causes of your pain.
For example, trigeminal neuralgia is less likely if you are under 40 years old, and multiple sclerosis (MS) may be more likely if you have a family history of the condition or if you have some other form of this condition. However, trigeminal neuralgia is very unlikely to be the first symptom of MS.
If your GP is not sure about your diagnosis, or if you have unusual symptoms, they may refer you for a magnetic resonance imaging (MRI) scan of your head.
An MRI scan uses strong magnetic fields and radio waves to create detailed images of the inside of your head. It can help identify potential 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 detect whether a blood vessel in your head is compressing one of the trigeminal nerves, which is one of the main causes of trigeminal neuralgia. However, highly sophisticated MRI scans may be needed to show this accurately, although this may not necessarily be helpful, because not everyone with a compressed trigeminal nerve has trigeminal neuralgia.
Treating trigeminal neuralgia
There are a number of treatments available that can offer some relief from the pain caused by trigeminal neuralgia.
Identifying triggers and avoiding them can also help.
Most people with trigeminal neuralgia will be prescribed medication to help control their pain, although surgery may be considered for the longer term in those cases where medication is ineffective or causes too many side effects.
The painful attacks associated with trigeminal neuralgia can sometimes be triggered or made worse by a number of different things. Therefore, in addition to your medical treatment, it may help to try to avoid these triggers, if possible.
For example, if your pain is triggered by wind or even a draught in a room, it may help to avoid sitting near open windows or the source of air conditioning, and wearing a scarf wrapped around your face in windy weather. A transparent dome-shaped umbrella can also protect your face from the weather.
Hot, spicy or cold food or drink may also trigger your pain, so avoiding these can help. Using a straw to drink warm or cold drinks may also help prevent the liquid coming into contact with the painful areas of your mouth. It is important to eat nourishing meals, however, so if you are having difficulty chewing, consider eating mushy foods or liquidising your meals.
Certain foods seem to trigger attacks in some people, so you may want to consider avoiding things such as caffeine, citrus fruits and bananas.
As normal painkillers such as paracetamol are not effective in treating trigeminal neuralgia, you will normally be prescribed an alternative medication, such as an anticonvulsant medication (usually used to treat epilepsy) to help control your pain.
These medications were not originally designed to treat pain, but they can help relieve nerve pain by slowing down electrical impulses in the nerves and reducing their ability to transmit pain.
They need to be taken regularly, not just when the pain attacks occur, but can be stopped when the episodes of pain cease and you are in remission. Unless otherwise instructed by your GP or specialist, it is important to build up the dosage slowly and reduce it again gradually over a few weeks. Taking too much too soon and stopping the medication too quickly can cause serious problems.
Initially, your GP will probably prescribe a type of anticonvulsant called carbamazepine, although a number of alternatives are available if this is ineffective or unsuitable.
The anticonvulsant carbamazepine is currently the only medication licensed for the treatment of trigeminal neuralgia in the UK. It can be very effective initially, but may become less effective over time.
You will usually need to take this medicine at a low dose once or twice a day, with the dose slowly increasing up to four times a day until it provides satisfactory pain relief.
Carbamazepine often causes side effects, which may make it difficult for some people to take. These include:
tiredness and sleepiness
difficulty concentrating and memory problems
feeling unsteady on your feet
feeling sick and vomiting
a reduced number of infection-fighting white blood cells (leukopenia)
allergic skin reactions, such as urticaria (hives)
You should speak to your GP if you experience any persistent or troublesome side effects while you are taking carbamazepine, especially 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.
Carbamazepine may stop working over time. If this occurs, or if you experience significant side effects while taking it, you should be referred to a specialist to consider alternative medications or procedures.
There are a number of specialists you may be referred to for further treatment, including neurologists specialising in headaches, neurosurgeons and pain medicine specialists (for example, at a pain clinic).
In addition to carbamazepine, there are a number of other medications that have been used to treat trigeminal neuralgia, including:
None of these medications are specifically licensed for the treatment of trigeminal neuralgia, which means they have not undergone rigorous clinical trials to determine whether they are effective and safe to treat the condition.
However, this is largely only because trigeminal neuralgia is a rare condition, and clinical trials are difficult to carry out on such a painful condition because giving some people an inactive, "dummy" medication (placebo) to compare these medications to would be unethical and impractical.
However, many specialists will prescribe an unlicensed medication if they think it is likely to be effective and the benefits of treatment outweigh any associated risks.
If your specialist is considering prescribing an unlicensed medication to treat trigeminal neuralgia, they should inform you that it is unlicensed and discuss possible risks and benefits with you.
With most of these medications, the side effects can be quite difficult to cope with initially. Not everyone experiences side effects, but if you do, try to persevere because they do tend to diminish with time or at least until the next dosage increase, when you may find a further period of adjustment is necessary. Talk to your GP if you are finding the side effects unbearable.
Surgery and procedures
If medication does not adequately control your symptoms or is causing persistently troublesome side effects, you may be referred to a specialist to discuss the different surgical and non-surgical options available to relieve your pain.
There a number of procedures that have been used to treat trigeminal neuralgia, so you will need to discuss the potential benefits and risks of each treatment with your specialist before making a decision. It is wise to be as informed as possible and to make the choice that it right for you as an individual.
There is no guarantee that one or any of these procedures will work for you but, once you have had a successful procedure, you won’t need to take your pain medications unless the pain returns. If one procedure does not work, you can always try another or remain on your medication temporarily or permanently.
Some of the procedures that can be used to treat people with trigeminal neuralgia are outlined below.
There are a number of procedures that can offer some relief from trigeminal neuralgia pain, at least temporarily, by inserting a needle or thin tube through the cheek and into the trigeminal nerve inside the skull.
These are known can "percutaneous" (through the skin) procedures, and they are carried out using X-rays to guide the needle or tube into the correct place while you are heavily sedated with medication or under a general anaesthetic (where you are asleep).
Percutaneous procedures that can be carried out to treat people with trigeminal neuralgia include:
glycerol injections – where a medication called glycerol in injected around the Gasserian ganglion (where the three main branches of the trigeminal nerve join together)
radiofrequency lesioning – where a needle is used to apply heat directly to the 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; the balloon is then removed
These procedures work by deliberately injuring or damaging the trigeminal nerve, which is thought to disrupt the pain signals travelling along it. You are usually able to go home the same day, following your treatment.
Overall, all of these procedures are similarly effective in relieving trigeminal neuralgia pain, although there can be complications with each, and these vary with the procedure and the individual. The pain relief will usually only last a few years, and sometimes only a few months. Sometimes these procedures do not work at all.
The major side effect of these procedures is numbness of part or all the side of the face, and this can vary in severity from being very numb or just pins and needles. The sensation, which can be permanent, is often similar to that following an injection at the dentist. Very rarely, you can get a combination 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.
An alternative way to relieve pain by damaging the trigeminal nerve that doesn't involve inserting anything through the skin is stereotactic radiosurgery. This is a fairly new treatment that uses a concentrated beam of radiation to deliberately damage the trigeminal nerve where it enters the brainstem.
Stereotactic radiosurgery does not require a general anaesthetic and no cuts (incisions) are made in your cheek.
A metal frame is attached to your head with four pins inserted around your scalp (a local anaesthetic is used to numb the areas where these are inserted) and your head, complete with the frame attached, is held in a large machine for an hour or two (which may make you feel claustrophobic) while the radiation is given. The frame and pins are then removed, and you are able to go home after a short rest.
It can take a few weeks – or sometimes many months – for this procedure to take effect, but it can offer pain relief for some people for several months or years. Studies into this treatment have shown similar results to the other procedures mentioned above.
The most common complications associated with stereotactic radiosurgery include 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 help relieve trigeminal neuralgia pain without damaging the trigeminal nerve. Instead, the procedure involves relieving the pressure placed on the nerve by blood vessels that are touching the nerve or wrapped around it.
This is a major procedure that involves opening up the skull, and is carried out under general anaesthetic by a neurosurgeon.
During MVD, the surgeon will make an incision in your scalp, behind your ear, and remove a small circular piece of skull bone. They will then either remove or relocate the blood vessel(s), separating them from the trigeminal nerve using an artificial pad or a sling constructed from adjoining tissue.
For many people, this type of surgery is effective in easing or completely stopping the pain of trigeminal neuralgia. It provides the longest lasting relief, with some studies suggesting that pain only recurs in about 30% of cases within 10-20 years of surgery. Currently, this is the closest possible cure for trigeminal neuralgia.
However, it is an invasive procedure and carries a risk of potentially serious complications, such as hearing loss, stroke and even death (in around 1 in every 200 cases) – although it only rarely causes facial numbness.
More information and support
Living with a long-term and painful condition such as trigeminal neuralgia can be very difficult.
You may find it useful to contact local or national support groups, such as the Trigeminal Neuralgia Association UK, for more information and advice about living with the condition, and to get in touch with other people who have the condition to talk to them about their experiences.
Research has shown that groups that have support from health care professionals provide high-quality help, which can significantly improve your ability to manage this rare condition. Learning from others how to cope can help remove the fear of more pain and reduce the risk of depression.
However, you need to be wary of potentially unreliable information you may find elsewhere, especially if offering “cures” for the condition. There is a great deal of misinformation on the internet, so do your research only on reliable websites, not on open forums or on social media.
There are a number of research projects running both in the UK and abroad to determine the cause of this condition and to find new treatments, including new medications, so there is always hope on the horizon