Trigeminal Neuralgia

Overview

Trigeminal neuralgia is a condition that causes painful sensations similar to an electric shock on one side of the face. This chronic pain condition affects the trigeminal nerve, which carries sensation from your face to your brain. If you have trigeminal neuralgia, even mild stimulation of your face — such as from brushing your teeth or putting on makeup — may trigger a jolt of excruciating pain.

You may initially experience short, mild attacks. But trigeminal neuralgia can progress and cause longer, more-frequent bouts of searing pain. Trigeminal neuralgia affects women more often than men, and it's more likely to occur in people who are older than 50.

Because of the variety of treatment options available, having trigeminal neuralgia doesn't necessarily mean that you're doomed to a life of pain. Doctors usually can effectively manage trigeminal neuralgia with medications, injections or surgery.

Symptoms

Most patients report that their pain begins spontaneously and seemingly out of nowhere. Other patients say their pain follows a car accident, a blow to the face or dental work. In the cases of dental work, it is more likely that the disorder was already developing and then caused the initial symptoms to be triggered. Pain often is first experienced along the upper or lower jaw, so many patients assume they have a dental abscess. Some patients see their dentists and actually have a root canal performed, which inevitably brings no relief. When the pain persists, patients realize the problem is not dental-related.

The pain of TN is defined as either type 1 (TN1) or type 2 (TN2). TN1 is characterized by intensely sharp, throbbing, sporadic, burning or shock-like pain around the eyes, lips, nose, jaw, forehead and scalp. TN1 can get worse resulting in more pain spells that last longer. TN2 pain often is present as a constant, burning, aching and may also have stabbing less intense than TN1.

TN tends to run in cycles. Patients often suffer long stretches of frequent attacks, followed by weeks, months or even years of little or no pain. The usual pattern, however, is for the attacks to intensify over time with shorter pain-free periods. Some patients suffer less than one attack a day, while others experience a dozen or more every hour. The pain typically begins with a sensation of electrical shocks that culminates in an excruciating stabbing pain within less than 20 seconds. The pain often leaves patients with uncontrollable facial twitching, which is why the disorder is also known as tic douloureux.

Pain can be focused in one spot or it can spread throughout the face. Typically, it is only on one side of the face; however, in rare occasions and sometimes when associated with multiple sclerosis, patients may feel pain in both sides of their face. Pain areas include the cheeks, jaw, teeth, gums, lips, eyes and forehead.

Attacks of TN may be triggered by the following:

• Touching the skin lightly
• Washing
• Shaving
• Brushing teeth
• Blowing the nose
• Drinking hot or cold beverages
• Encountering a light breeze
• Applying makeup
• Smiling
• Talking

The symptoms of several pain disorders are similar to those of trigeminal neuralgia. The most common mimicker of TN is trigeminal neuropathic pain (TNP). TNP results from an injury or damage to the trigeminal nerve. TNP pain is generally described as being constant, dull and burning. Attacks of sharp pain can also occur, commonly triggered by touch. Additional mimickers include:

Temporal tendinitis

• Ernest syndrome (injury of the stylomandibular ligament
• Occipital neuralgia
• Cluster headaches/ migraines
• Giant cell arteritis
• Dental pain
• Post-herpetic neuralgia
• Glossopharyngeal neuralgia
• Sinus infection
• Ear infection
• Temporomandibular joint syndrome (TMJ)

causes

There are several conditions that may cause trigeminal neuralgia, but it’s typically caused by a blood vessel exerting pressure on the nerve near your brain stem. MS causes the deterioration of the nerve coating called the myelin sheath, so people with MS may also develop TN.

This condition can also be caused by a tumor or lesion that compresses your nerves, though this isn’t nearly as common. If you damage your trigeminal nerve through oral or sinus surgery, a stroke or from facial trauma, you may feel facial nerve pain that’s similar to the symptoms of trigeminal neuralgia.

Some cases of trigeminal neuralgia are idiopathic — meaning no specific cause is identified.

Diagnosis

Diagnosing trigeminal neuralgia involves a physical exam and a detailed medical history to rule out other causes of facial pain. Your health care provider (usually your primary care doctor or a neurologist) will ask about the frequency and intensity of the pain, what seems to set it off and what makes it feel better or worse. Since there is no single test for trigeminal neuralgia, getting to the nature of the pain is key to the diagnosis.

Your provider may also recommend imaging or laboratory tests, such as a CAT scan or a high-resolution MRI of the trigeminal nerve and surrounding areas. These tests can help determine if the pain is caused by a tumor or blood vessel abnormality, or by undiagnosed multiple sclerosis. Certain advanced MRI techniques may help the doctor see where a blood vessel is pressing against a branch of the trigeminal nerve.

Treatment

A number of treatments 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 medicine to help control their pain, although surgery may be considered for the longer term in cases where medicine is ineffective or causes too many side effects.

Avoiding triggers

The painful attacks of trigeminal neuralgia can sometimes be brought on, or made worse, by certain triggers, so it may help to avoid these triggers if possible.

For example, if your pain is triggered by wind, it may help to wear a scarf wrapped around your face in windy weather. A transparent dome-shaped umbrella can also protect your face from the weather.

If your pain is triggered by a draught in a room, avoid sitting near open windows or the source of air conditioning.

Avoid hot, spicy or cold food or drink if these seem to trigger your pain. Using a straw to drink warm or cold drinks may also help prevent the liquid coming into contact with painful areas of your mouth.

It's important to eat nourishing meals, so consider eating mushy foods or liquidising your meals if you're having difficulty chewing.

Certain foods seem to trigger attacks in some people, so you may want to consider avoiding things such as caffeine, citrus fruits and bananas.

Medicine

As painkillers like paracetamol are not effective in treating trigeminal neuralgia, you'll usually be prescribed an anticonvulsant – a type of medicine used to treat epilepsy – to help control your pain.

Anticonvulsants were not originally designed to treat pain, but they can help to relieve nerve pain by slowing down electrical impulses in the nerves and reducing their ability to send pain messages.

They need to be taken regularly, not just when the pain attacks happen, but you can stop taking them if the episodes of pain cease and you're in remission. 

Unless a GP or specialist tells you to take your medicine in a different way, it's important to increase your dosage slowly. If the pain goes into remission, you can gradually reduce the dosage over the course of a few weeks. Taking too much too soon, or stopping the medicine too quickly can cause serious problems.

At the start, the GP will probably prescribe a type of anticonvulsant called carbamazepine, although a number of alternative anticonvulsants are available if this is ineffective or unsuitable.

These include:

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

You should speak to a GP if you experience any persistent or troublesome side effects while taking carbamazepine, particularly 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.

Immediately report any suicidal feelings to a GP. If this is not possible, call NHS 111. 

Other medicines

Carbamazepine may stop working over time. In this case, or if you experience significant side effects while taking it, you should be referred to a specialist to consider alternative medicines 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.

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

• oxcarbazepine
• lamotrigine
• gabapentin
• pregabalin
• baclofen

None of these medicines are specifically licensed for the treatment of trigeminal neuralgia, which means they have not undergone rigorous clinical trials to determine whether they're effective and safe to treat the condition.

However, many specialists will prescribe an unlicensed medicine if they think it's likely to be effective and the benefits of treatment outweigh any associated risks.

If your specialist prescribes you an unlicensed medicine to treat trigeminal neuralgia, they should inform you that it's unlicensed and discuss the possible risks and benefits with you.

Read more about the licensing of medicines.

The side effects associated with most of these medicines can initially be quite difficult to cope with.

Not everyone experiences side effects, but if you do, try to persevere as they often diminish with time or at least until the next dosage increase.

Talk to a GP if you're finding the side effects very troublesome.

Surgery and procedures

If medicine 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 you.

A number of procedures have been used to treat trigeminal neuralgia, so discuss the potential benefits and risks of each one with your specialist before you make a decision.

There's no guarantee that any of these procedures will work for you. However, if a procedure is successful, you will no longer need to take pain medicines unless the pain returns.

If one procedure does not work, you can try another procedure, or keep taking medicines for the short term or permanently.

Some of the procedures that can be used to treat trigeminal neuralgia are outlined below.

Percutaneous procedures

There are a number of procedures that can offer some relief from the pain of trigeminal neuralgia, at least temporarily, by inserting a needle or thin tube through the cheek and into the trigeminal nerve inside the skull.

These are known as percutaneous procedures. X-rays of your head and neck are taken to help guide the needle or tube into the correct place while you're heavily sedated with medicine or under a general anaesthetic, where you're unconscious.

Percutaneous procedures to treat trigeminal neuralgia include:

glycerol injections – where a medicine called glycerol is injected around the Gasserian ganglion, where the 3 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 that has been inserted through the cheek. The balloon is then 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're usually able to go home the same day.

Overall, these procedures are similarly effective in relieving trigeminal neuralgia pain, although there can be complications with each. These vary depending on the procedure and the individual.

The pain relief will usually only last a few years or, in some cases, a few months. Sometimes these procedures do not work at all.

The major side effect of these procedures is numbness in part or all of one side of the face, which can vary from being very numb or just pins and needles.

The sensation, which can be permanent, is often similar to the feeling you have after an injection at the dentist. You can also develop a combination of numbness and continuous pain called anaesthesia dolorosa, which is virtually untreatable, however this is very rare.

These procedures also carry a risk of other short- and long-term side effects and complications, including bleeding, facial bruising, eye problems and impaired hearing on the affected side. Very rarely, it can cause a stroke.

Stereotactic radiosurgery

Stereotactic radiosurgery 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 4 pins inserted around your scalp – a local anaesthetic is used to numb the areas where these are inserted.

Your head, including the frame, is held in a large machine for 1 to 2 hours while the radiation is given. The frame and pins are then removed, and you're able to go home after a short rest.

It can take a few weeks – or sometimes many months – to notice any change after stereotactic radiosurgery, but it can offer pain relief for some people for several months or years.

Facial numbness and pins and needles in the face are the most common complications associated with stereotactic radiosurgery. These side effects can be permanent and, in some cases, very troublesome.

Microvascular decompression

Microvascular decompression (MVD) is an operation that can help relieve trigeminal neuralgia pain without intentionally damaging the trigeminal nerve.

The procedure relieves the pressure placed on the trigeminal nerve by blood vessels that are touching the nerve or are wrapped around it.

MVD is a major procedure that involves opening the skull, and is carried out under general anaesthetic by a neurosurgeon.

A surgeon makes an incision in your scalp, behind your ear, and removes a small piece of skull bone. They then separate the blood vessel(s) from the trigeminal nerve using an artificial pad or a sling constructed from adjoining tissue.

Many people find this surgery is effective at easing or completely stopping the pain of trigeminal neuralgia.

It provides the longest lasting relief, with some studies suggesting that pain returns in about 3 out of 10 cases within 10 to 20 years of surgery.

Currently, MVD is the closest possible cure for trigeminal neuralgia. However, it's an invasive procedure and carries a risk of potentially serious complications, such as facial numbness, hearing loss, stroke and even death in around 1 in every 200 cases.

Further 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 a local or national support group, 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.

A number of research projects are running both in the UK and abroad to find the cause of trigeminal neuralgia and develop new treatments and new medicines, so there's hope for the future.