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Face pain
A guide for patients and carers
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Trigeminal neuralgia
What are the symptoms?
The pain usually only affects one side of the face. It can be felt on the skin or in the mouth and teeth. It comes and goes suddenly and unpredictably. Words often used to describe this sort of pain are: stabbing, lacerating, electric shock-like and shooting, and it can range in severity from a mild to a violent and excruciating pain. Each burst of pain lasts for only a few seconds, but there can be many of these bursts of pain in quick succession. The pain commonly affects the jaw and cheek area, but it may cover the whole of one side of the face. There are frequently “trigger points” on the skin, which if touched will bring on a violent spasm of pain. The pain may be brought on by cleaning the teeth, washing the face, shaving, hot or cold drinks, talking, or even the wind.
Attacks of pain may come and go at first with long periods of relief occurring between them. People may experience pain every day for weeks or months and then it may disappear completely for months or even years. For many, these attacks become more frequent and last longer as time goes on. For some, the pain shoots continuously.
Trigeminal neuralgia will not clear up of its own accord, and whilst there may be long pain-free periods in the early stages, the condition is a permanent one unless effective treatment is received.
The early symptoms can take many different forms, so trigeminal neuralgia can be difficult to identify at first. Many people have extensive treatment from their dentist or others, before the diagnosis eventually becomes apparent. However, the condition is not caused by dental treatment.
What does it affect?
Trigeminal neuralgia can affect people of all ages, though it very rarely
occurs in children. It is more common in the older age groups than in young adults and it is twice as common in women as men. It affects the right side of the face twice as frequently as it does the left and it very rarely affects both sides. It is not hereditary. It is estimated that one in every 1,000 people may be affected by or have had trigeminal neuralgia.
What causes trigeminal neuralgia?
The cause of the majority of cases of trigeminal neuralgia has not been conclusively established. Different theories suggest that the underlying problem lies within the brain, the nerves inside the head or the nerve as it passes through the face. Currently, the most popular theory is that a blood vessel presses on the trigeminal nerve as it emerges from the base of the brain inside the skull. This is known as vascular compression. The compression causes the insulating material, called myelin, around the nerves to be broken down, so that the brain thinks that a light touch on the face is a painful sensation. Many neurosurgeons believe that this is the most widespread cause of trigeminal neuralgia, but there are others who
disagree.
Of the less than five per cent of cases of trigeminal neuralgia where a clear cause is confirmed, a tumour (which is nearly always benign), or infected tissue is found to be pressing on the nerve. The condition occasionally affects people with established multiple sclerosis, though it is virtually never their first symptom. In other words, if you have trigeminal neuralgia there is no reason to suspect that you may be developing multiple sclerosis or any other serious condition.
How is it diagnosed?
Because the nerves function normally and there is no test which can prove that the condition is trigeminal neuralgia, the doctor has to rely totally on an accurate description of the symptoms and a careful examination. They also need to rule out other possible causes of facial and oral pain. These include problems with the teeth, mouth, ears, skull and the glands around the mouth and face, so these areas will be carefully examined and you may be advised to see a dentist.
Cluster headaches, or migrainous neuralgia, can produce very similar
symptoms to trigeminal neuralgia, so the doctor may also need to rule this out (see the Brain and Spine Foundation’s Headache booklet for more information on cluster headaches).
A brain scan may be carried out to rule out the possibility that a lesion or tumour in the head could be putting pressure on the nerves. Some neurosurgeons believe that developments in the technique of MRI scanning may enable them to detect the blood vessels thought to be responsible for the majority of cases of trigeminal neuralgia. However, these new methods are still the subject of research. These blood vessels cannot accurately be seen using standard MRI scanning methods, so in many cases of true primary trigeminal neuralgia, the scan will not usually reveal any abnormalities.
What medicines are available?
The commonest and one of the most effective drugs available to treat this condition is carbamazepine (Tegretol). This is a well established anticonvulsant drug that was originally developed for the treatment of epilepsy. It works by dampening the activity in excitable nerves.
Carbamazepine may cause a rash in around seven per cent of users, and you should let your doctor know if this happens to you. There are also a number of other rarer side effects that should be discussed with your doctor before you start taking carbamazepine. Carbamazepine interferes with the action of many other drugs, so it is important that anyone treating you knows that you are taking it.
Regular blood tests are required when you first start to take carbamazepine and it may be necessary to take large quantities of the drug and increase the dosage over time. Its main side effects are drowsiness, lack of concentration and unsteadiness. Because of this, some people don’t take the full dose, and this results in pain breaking through. However, for 75 per cent of people carbamazepine is an effective treatment.
Gabapentin (neurontin), a new drug, has been tried extensively in post-herpetic neuralgia but there are only a few reports of its use in trigeminal neuralgia. It is however used frequently because although it is less effective than carbamazepine, it causes less side effects.
Baclofen is a muscle relaxant. It is usually used in combination with carbamazepine or phenytoin and is effective in the early stages of the condition. A range of doses may be used.
Lamotrigine has been found to be effective when added to carbamazepine. Lamotrigine has to be started at a low dose and gradually increased if the principal side effect of a rash is to be avoided.
Phenytoin (Epanutin), sodium valproate (Epilim) and clonazepam (Rivotril) are anti-epileptic drugs that may be used instead of or in combination with carbamazepine. They may not be as effective, but they are useful if you cannot take carbamazepine.
Although only recently licensed for use in the UK, oxcarbazepine (Trileptal) has been used extensively in other countries. It has similar properties to carbamazepine but causes fewer side effects. It has become the drug of choice in the Scandinavian countries.
The dosage of these drugs can be tailored to individual needs and is likely to be increased over time. This is because unfortunately, the pain tends to become more severe. Only you know how much pain you feel, and because of this you should take control by making sure you take the prescribed dosage and also by monitoring how well the pain responds to the dosage you are on. A good way to do this is to keep a daily “pain diary” (see figure 2) which you can then show to your doctor.
What about surgery?
Drugs are the best initial form of treatment if they are controlling the pain. However, where the drugs fail to give relief or where they cause unacceptable side effects, the option of surgery may need to be considered. Evidence is beginning to emerge that earlier treatment – within eight years of developing trigeminal neuralgia – may improve the outcome after surgery. A number of different surgical methods are used to treat trigeminal neuralgia, and these are described below.
Interrupting the nerve
A number of different surgical methods are used to “interrupt” or block the electrical activity in the nerve. Whilst this may relieve the pain it will nearly always leave an area of numbness or loss of feeling in the face as the methods used destroy part of the nerve. The interruption can be made at one of three sites.
1. In the periphery of the face
The small branches of the nerve that pass inside the mouth and forehead may be cut (neurectomy), frozen (cryotherapy) or lasered. This can usually be done under local anaesthetic as a small surgical treatment. A small area of numbness may occur. Unfortunately, pain control is often only achieved for around ten months. It is usually only recommended when other treatments are not possible.
2. At the ganglion
The Gasserian ganglion lies just inside the bottom of the skull. It is a
swelling on the nerve, the size and shape of a split broad bean. It contains the cells that supply the nerve fibres of the trigeminal nerve.
This procedure is carried out using a light general anaesthetic or heavy sedation. A needle is passed via the cheek up through a small hole in the base of the skull to reach the ganglion. An x-ray is used to guide it.
The ganglion is then de-activated by injecting it with glycerol, or using heat (thermocoagulation), or alternatively it may be compressed with a small inflatable balloon positioned at the tip of the needle. These procedures are usually carried out with the patient under heavy sedation but partially awake so that the surgeon can confirm by stimulation that the needle has reached the correct place. An overnight stay in hospital may be required.
A larger area of the face can be treated with this technique than can usually be achieved by interrupting the nerve just below the surface of the skin as previously described. Again the majority of patients will develop numbness in the area being treated, though this is often not as complete as when the nerve is cut. The numbness feels like an injection for dental treatment wearing off. The severe, dull continuous pain in the numb area known as anaesthesia dolorosa may occur following this procedure in around two per cent of patients. Around 10 per cent of patients will experience some unpleasant sensations of the face which may affect the quality of life.
This technique carries a number of risks and these must be considered before deciding to go ahead with it. As the needle penetrates the skull, complications affecting the brain may arise. This occurs in less than one per cent of cases, but incidents of meningitis, brain abscess, brain haemorrhage and heart attack resulting from this procedure have been recorded, and these can result in death or permanent disability (mental or physical handicap).
It is worth noting that where the forehead is primarily affected it can be difficult to position the needle into that part of the nerve, so that a large area of numbness is created before the pain is relieved. An unfortunate by-product of this is that the eye (corneal) reflex is lost or reduced in around eight per cent of people treated by this method. This means that you don’t feel anything touching the eye, which can lead to further problems if the eye becomes scratched or infected. Around 10 per cent of people may experience some difficulties with eating for a few months after the procedure.
The procedure itself can be extremely unpleasant for some people, but for the majority of others the discomfort is not great and many people are prepared to undergo a second procedure if the pain returns.
3. At the nerve trunk
The nerve trunk is the portion of the nerve that emerges from the brain and extends to the ganglion. This procedure, called rhizotomy, is an operation requiring a general anaesthetic. This procedure is carried out on relatively few people. An opening at the base of the skull is made just behind the ear. The nerve is identified using a microscope and is then cut or crushed in order to divide the fibres that supply feeling to the part of the face which is affected by pain. This results in some numbness, though often less than might be expected. The operation involves a hospital stay of between five and 10 days and staying off work for a period of around six weeks.
This procedure often provides a long-term cure, but its main disadvantage is the need for an operation in such an important area of the brain. Even in the most expert hands and with the greatest possible care the risks are greater than with the other procedures described. The exact risk in each case will depend upon the age and general health of the person concerned, but the incidence of death is reported to be 0·5 per cent and the incidence of serious disability (mental or physical handicap) is reported to be one per cent.
In addition, there is a risk that the nearby nerves coming from the brain stem may be damaged. These include those supplying hearing and balance, so unsteadiness or deafness in one ear may occur in up to four per cent of people undergoing this treatment. More rarely, weakness affecting the face on the side where the operation was carried out, difficulty in swallowing, or double vision may be experienced following the operation. This damage to nearby nerves arises in just under two per cent of cases but many may improve over the months. Some people experience pain around the wound behind the ear or numbness of the ear after this procedure. This usually settles down, but it can go on for several months. Again, anaesthesia dolorosa may follow this procedure.
A technique called stereotactic radiosurgery or “Gamma Knife” treatment is currently being developed. This uses a highly focused beam of radiation to interrupt the nerve impulses just behind the ganglion and does not involve a surgical operation. Early results seem to suggest that rates of pain relief are similar to other interuptions. It is still being evaluated and its ability to provide long-term pain relief has not yet been assessed. It has the disadvantages that the benefits are delayed and that numbness may result, bringing with it concerns about future anaesthesia dolorosa.
Decompression of the nerve
A procedure called neurovascular (nerve vessel) decompression or
microvascular decompression has been developed in a bid to provide pain relief without nerve damage and consequent numbness or risk of anaesthesia dolorosa.
In this operation the surgeon makes the same opening as for the nerve trunk procedure described on page 10. The blood vessel found compressing the nerve as it emerges from the brain stem is moved away from the nerve and then a soft pad is placed between them. In 90-95 per cent of cases immediate pain relief is achieved by this procedure and there is evidence to show that about 70 per cent of people are pain-free 10 years later. This procedure rarely produces loss of sensation and there have been no reported cases of anaesthesia dolorosa.
The disadvantage of this procedure is that it again requires a formal operation and carries the same risks as the nerve trunk procedure (3) described earlier. It also requires a five- to 10-day stay in hospital.
Neurostimulation
As with several chronic pain conditions, attempts have been made to treat trigeminal neuralgia and other forms of facial pain with neurostimulation. A variety of methods have been used to apply this technique.All require the placement of an electrode onto the nerve or ganglion in the upper (cervical) cord.
It does not provide a cure and it is used on only a small minority of patients with chronic facial pain for whom it may provide some benefit. It is an issue that would need to be discussed with your specialist who may, if appropriate, refer you to an expert in this treatment.
What is the best course of action for me?
If the pain is controlled by the drugs you have been given, then this is likely to be the best form of treatment. However, if the drugs give no relief, or if they have side effects that you can’t cope with, you will need to give careful consideration to the surgical options that are available to you. This is something you will need to discuss with a specialist and possibly other organisations that provide information and support on this issue (see page 25).
Once you are clear about the potential benefits and risks you will need to weigh up whether you feel the risks are worth taking or not. You will need to think about whether the various options are likely to work, how long the benefits are likely to last and what sort of risk you will be taking.
The general view among specialists at the moment is that for young, healthy people the neurovascular decompression operation is likely to be the best option. It provides pain relief without numbness and usually does so in a lasting manner. For those who are generally unwell, elderly or frail and for those who cannot afford the time or are unwilling to take the risks associated with this form of surgery, the usual suggestion is to treat the condition by blocking the nerve at the ganglion, as described earlier. The benefits may not last as long and will usually be accompanied by an area of numbness. However, these procedures can be repeated and it is still possible to have surgery at a later date. Gamma knife treatment as described on page 11 may be an option for people who cannot undergo surgery for medical reasons.
You will need to con sider these factors carefully and should feel under no pressure to opt for a particular procedure against your own better judgement. All options should be available to you via the centre at which you are receiving treatment.
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Contents
- Introduction
- Trigeminal neuralgia
- Glossopharyngeal neuralgia
- Post-herpetic neuralgia
- Other causes of chronic facial pain
- Temporo mandibular joint dysfunction
- Atypical face pain / chronic facial pain
- Atypical odontalgia
- Burning mouth syndrome - Oral dysaesthesia
- Summary
- Other organisations that may be able to help
- Your feedback on Face Pain
