Facial Pain & Neuralgia
Patients will often refer to facial pain as neuralgia. In fact neuralgia is a fairly uncommon condition with the most common form Trigeminal Neuralgia affecting 4-5 in 100,000 people. Other types of neuralgia include Glossophatygeal Neuralgia, Recurrent Laryngeal Neuralgia both extremely rare and Post Herpetic Neuralgia which may develop after an attack of shingles.
All are intensely painful and will usually show no response with painkiller medication including the powerful opioid medications, such as morphine.
Trigeminal Neuralgia (TN) is commonly accepted along with Cluster headache as being the most severe form of pain experienced by mankind. It affects the face only and is a disorder of the trigeminal nerve which supplies the face and front area of the head. It has no particular cause and typically occurs in men and women over 50 years of age. It is a unique form of pain in that it can occur without provocation and sometimes with provocation and then at other times cannot be activated in any way. When provocable very light touch of the surface of the face or the inside of the mouth can lead to a devastating sharp pain described as being like a bolt of lightning or electric shock.
Many with TN will find that pain will not occur at any time during sleep and in most cases it goes through periods of pain remission where the individual will not experience any pain. This will also occur when the pain is active and it is often described how repeated triggering of the pain can bring about a brief remission. In this way some one who has difficulty chewing or swallowing may find that by continuing to do either or both that a period free from pain may result during which they will try to eat as quickly as possible before pain returns. Men may not be able to shave on the affected side and women may avoid putting on make-up on account of the triggering of pain.
Episodes of pain last seconds to minutes with usually some relief between and patients may adapt a contored facial expression to avoid facial movement in fear of triggering the pain.
The pain can generally be well controlled with the use of anti-convulsant medications which are used to control seizures. The dose of medication will vary from individual to individual and may need to gradually increased until the correct level is reached and apin is controlled and hopefully eliminated. The medication works in a different manner to ordinary painkillers and should be taken on a regular daily basis as instructed by the doctor. In most cases after a period without pain the medication can be stopped with the patient entering a pain-free period which may last from weeks to months. This is not always possible and some will take medication on a daly basis to prevent pain.
There are essentially three know reasons for TN. The first and most common reason is that there is a blood vessel, usually an artery, resting on the affected branch of the nerve. An MRI of the brain may be suggested in patients with confirmed TN to confirm this. An MRI is also used to check for the two other recognised causes of TN which are Multiple Sclerosis and a tumor in the base of the brain. The tumor if the cause is generally benign and something similar to a cyst and by increasing in size within the brain it created pressure on the trigemeinal nerva causing the pain of TN. Probably the most common tumor in this case is an acoustuic neuroma a benign growth that develops on the acoustic nerve which is close to the trigeminal nerve. Acoustic neuromas will tend to cause deafness on the affected side and is another immediate reason for removal as soon as located.
Unfortunately not all will manage with medications, either due to side-effects with medication or lack of pain control with medications and for these the next option is surgery. There are a range of surgeries for management of TN but essentially only two are offered in Ireland.
The first type of surgery involves a procedure to destroy the nerve fibres that are causing the pain. This has limited benefit in that pain may return after a few years and possibly at higher levels than before. It also has the undesirable effect of causing total numbeness (similar to the effects of a dental injection but permanent) in the area supplied by the nerve which either leads to total numbness in one side in the cheek area and upper lip or in the lower jaw, lip and tongue.
The second more effective surgery is brain surgery and its effect is to separate the nerve and blood vessel which are in contact and as this is on the undersurface of the brain itself it means that the neurosurgeon needs to access the skull itself to perform the procedure. Obviously this is a procedure whoich is only carried out if pain can not be controlled with medications alone.
GLOSSOPHARYNGEAL NEURALGIA and RECURRENT LARYNGEAL NEURALGIA
Both very rare with similar pains to TN both involving different nerves in the neck. Pain may occur in the throat area with swallowing particularly cold fluids. Management is similar to TN.
Post Herpetic Neuralgia (PHN) is a condition which like other neuralgias is extremely painful. It always develops following an outbreak of shingles. It is more common in older patients and may involve any division of the trigeminal nerve with the most commonly affected area being the forhead and scalp strictly on one side. It is also seen in the second division of the trigeminal nerve and in this case is seen to develop in the mouth usually on one side of the roof of the mouth.
The pain is often described as an intense burning sensation with episodic episodes of very intense sharp brief pains as in other neuralgias. Management is difficult and involves the use of anti-seizure and older group of anti-depressant medications. Application of anaesthetic paste in an adhesesive patch is also often beneficial. It is likely that early diagnosis and treatment of the preceding shingles, as soon as the blisters or vesicles are noted, with anti-viral treatments reduces the likelihood of PHN developing.