Trigeminal neuralgia (TN) is a condition that causes recurring severe pains in parts of your face.It usually affects people aged over 50. Treatment with a drug called carbamazepine usuallyworks well to stop the pains. Surgery is an option if medication does not work, or if side-effectsfrom the medication are a problem.
1) What is the trigeminal nerve: The trigeminal nerve (also called the fifth cranial nerve) is one of the main nerves of theface. There is one on each side.It comes through the skull from the brain in front of the ear.It has three branches.The first branch go to your scalp, forehead and around your eye. The second branch go tothe area around your cheek. 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 fromyour face, teeth and mouth. The trigeminal nerve also controls the muscles used in chewing,and the production of saliva and tears.
2) What is trigeminal neuralgia (TN) and what are the symptoms: Neuralgia means pain coming from a nerve. In TN you have sudden pains that come from one or more branches of the trigeminal nerve. The pains are usually severe. The second and third branches are the most commonlyaffected. Therefore, the pain is usually around your cheek or jaw or both. The first branch is less commonlyaffected so pain over your forehead and around your eye is less common. TN 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 lastup to two minutes. The pain can be so sudden and severe that you may jerk or grimace with pain. The timebetween each pain may be minutes, hours, or days. Sometimes several pains repeat in quick succession. After anattack 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 usually 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 oftenaround the nose and mouth. Washing the face, shaving, eating, talking, smoking, brushing teeth, or swallowingmay trigger a pain. Between attacks of pain, there are usually no other symptoms, the nerve works normally, and adoctor’s examination would find no abnormality.
3) What causes trigeminal neuralgia: About 9 in 10 cases are caused by a blood vessel that presses on the root of the nerve where the nerve comes outfrom the brain through the skull. However, it is not known why a blood vessel should start to press on thetrigeminal nerve in later life. Rarely, TN may be a symptom of another condition. For example, TN may develop asa result of a tumour, multiple sclerosis, or an abnormality of the base of the skull. In some people the cause is notknown.
4) Who gets trigeminal neuralgia: TN is uncommon. About 10 people in 100,000 develop it each year. It mainly affects older people, and it usuallystarts in your 60s or 70s. It is rare in younger adults. Women are more commonly affected than men.
5) 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. Thefrequency of the 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 passbetween bouts of pains. It is impossible to predict when the next bout of pains will occur, or how often the boutswill recur. Bouts of pains tend to become more frequent as you become older.
Do I need a brain scan or other tests?
Your doctor will advise if you need an MRI scan, to rule out any underlying cause.
6) What are the drug treatments for trigeminal neuralgia: Carbamazepine is the usual treatment
Carbamazepine is classed as an anticonvulsant drug. It is normally used to treat epilepsy. TN is not epilepsy.However, the effect of carbamazepine is to quieten nerve impulses and it often works well for TN. There is a goodchance that carbamazepine will ease symptoms of TN within 1-2 days.Side-effects occur in some people who take carbamazepine. Side-effects are more likely if higher doses areneeded. The most common include: drowsiness, feeling sick, tiredness, and dizziness. Quite often these are onlytemporary, so it is worth persisting with the drug if the pains ease and side-effects are not too bad.
Other drugs are also available.Surgical options for treatment
An operation is an option if medication does not work or causes troublesome side-effects. Basically, surgery for TNfalls into two categories:
This means an operation to relieve the pressure on the trigeminal nerve. Many cases of TN are due to a bloodvessel in the brain pressing on the trigeminal nerve as it leaves the skull. An operation can ease the pressure fromthe blood vessel (decompress the nerve) and therefore ease symptoms. This operation has the best chance of longterm relief of symptoms. However, it is a major operation involving a general anaesthetic and ‘brain surgery’ to getto the root of the nerve within the brain. Although usually successful, there is a small risk of serious complicationssuch as a stroke or deafness following this operation. A very small number of people have died as a result of thisoperation.
Ablative surgical treatments
Ablative means ‘to destroy’. There are various procedures that can be used to ‘destroy’ the root of the trigeminalnerve, and thus ease symptoms. For example, one procedure is called stereotactic radiosurgery (gamma knifesurgery). This uses radiation targeted at the trigeminal nerve root to destroy the nerve root. The advantage of these ablative procedures is that they can be done much more easily than decompression surgery as they do notinvolve formal ‘brain surgery’. So, there is much less risk of serious complications or death than there is withdecompression surgery. However, there is more of a risk that you will be left with a lack of sensation in a part of your face or eye as the treatment may mean that the trigeminal nerve will not function normally again. Also, thereis a higher chance that the symptoms will return at some stage in the future compared to decompression surgery.The chance of a cure from both decompression and ablative treatments is good. But, there are pros and cons of each. If you are considering surgery, the advice from a specialist is essential to help you decide which procedure isbest for you.
Compiled in year 2008.This article is for information only and should not be used for the diagnosis ortreatment of medical conditions. We have used all reasonable care in compiling the information but make nowarranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions.
Dr. Arun K. Dhanuka
MBBS, MD, DM (Neurology)
1799/1, Maharaj Nagar, Near PAU Gate No. 3,Ludhiana (Punjab).Ph: 0161-4662345, 98550-30365, 98147-20265.