Trigeminal Neuralgia

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The term Trigeminal Neuralgia (TN), has two words within it. Trigeminal nerve is one of the (twelve) cranial (head) nerves which has three divisions (ophthalmic, maxillary, and mandibular) supplying to the areas of upper eye-lid to the lower chin. Neuralgia means pain. TN is a disorder of the Trigeminal nerve which presents as facial pain and headache. The pain is characteristically severe, intense, sharp, episodic, periodical, excruciating, stabbing and short lasting.

Trigeminal nerve is the largest of twelve cranial nerves. All sensations from the face and mouth are covered by the Trigeminal nerve. One of the branches of the Trigeminal is often injected by your dentist while working on your dental cavity.

TN is also known as tic douloureux.

When the patient's Trigeminal nerve during an acute neuralgia phase was studied under electron microscope, it was revealed that the abnormality existed at the level of the inner nerve fibers called axons which carry nerve sensation, as well as the myelin (the nerve lining covering the nerve fibers). Due to the damage to such delicate parts, the nerve fiber behave like electrical wire with open ends, leading to electric shock like pain induced by touch or jerk.

Symptoms of Trigeminal Neuralgia

As TN is typically described by the patients as extremely severe episodes of pain. Probably the most painful condition known to the human race! The pain is described as lancinating, stabbing, excruciating, stitching, periodic, as if electric shock is given to some points on the face. The pain may appear suddenly, may last for a fraction of second or may be for a few minutes. In rare cases it may last for a couple of hours, making the patients almost immobile, whereby he or she may not be able to do any other activity. One would tend to hold the affected part until pain settles.

The TN is more common in the age group of 50 years plus. However, younger people as well as children may also present with TN. The pain may get triggered either without any cause or by certain motions involving the facial muscles, such as washing face, brushing teeth, gargling, shaving, applying facial make-up, touching the face, blowing, kissing, etc. The pain may initiate in any of the parts supplied by the Trigeminal nerve. However, it may vary from patient to patient depending on which of the three divisions of the Trigeminal nerve is affected. It may present with pain in the head, upper face, cheeks, dental pain, pain in lips, side of tongue, chin, etc. In some cases the pain may present as dull aching, burning, constant pain. Usually, one of the sides (right or left) is affected. The cause: The exact cause of TN remains a mystery. It is observed to run in families, indicating genetic predisposition. Detailed case study in our practice has shown history of prolonged stress in many cases. Prolonged underlying anxiety with the background of genetic diathesis may make one prone to this painful condition.

It is uncommon that TN will disappear spontaneously. However, there may be natural remissions or cyclical appearance of TN symptoms.

Causes

The exact cause of trigeminal neuralgia is not known but there are certain factors that can trigger the onset of trigeminal neuralgia. Stress and genetic tendency are the main factors that are significant for trigeminal neuralgia as causations. Apart from these, in some cases physical damage to the nerve caused by dental or surgical procedures, injury to the face or infections may be responsible for it.

Stress: Psychological stress is the cause as well as out come of disease like trigeminal neuralgia. It is a well-known fact that there is inseparable bond between mind and body and the psyche plays a vital role in maintaining health or causing diseases. It is a common experience in clinical practice that patients report the onset of trigeminal neuralgia following major stress like divorce, death of close relatives, change of job, unhealthy family relationships etc and this perception of patients that psychological stress can worsen trigeminal neuralgia has been supported in clinical studies.

Stress has been identified as an important cause in triggering as well as maintaining trigeminal neuralgia especially in the chronic cases. Stress can be in the form of:

• Prolonged anxiety due to any cause

• Grief, depression

• Suppressed anger/emotions

• Guilt

• Frustrations

• Despair

• Disappointments in life

• Nervous temperament

Frustration due to the unexplainable nature of the disease only makes the matters worse for the patient. Not all cases have a clear cut cause and heredity seems to play an important role in certain cases.

Factors lowering seizures threshold hence increasing the chances of seizures (TN):

Factors governing Pain and seizure threshold:

Episodes of trigeminal neuralgia increase when the patients pain threshold gets low. The pain threshold is affected by several known and unknown factors, some of them are:  

• Stress

• Exposure of cold wind

• Brain trauma

• Inadequate sleep

• Poisoning with lead or other chemicals

• Hormonal fluctuation before and after the menses

• Hyperglycemia (High blood sugar)

• Certain antibiotics and anesthetic agents

Diagnosis

The diagnosis of TN is made clinically. In most cases the very description offered by the patients is diagnostic. There is no specific investigation or tests to diagnose TN. CT scan or an MRI is conducted only if some other pathology (tumor or multiple sclerosis) is suspected in the facial or brain areas which may have presented a confused clinical picture.

At times, TN resembles certain other clinical conditions which have to be ruled out to establish the diagnosis of TN. The conditions which may present with symptoms similar to TN are: sinusitis, migraine headache, dental cavities, other forms of neuritis

Treatment

Traditional treatment with anticonvulsive medication does not help all the patients, all the time. Carbamazepine is among the most commonly used medicines. It is known to help TN. However, carbamazepine has many shortcomings. It needs to be taken for a very long period and it can have many side effects. Surgical treatment, microvascular decompression, Gamma Knife (high-intensity, highly focused radiation) help some for a variable amount of time. Many of the patients get relapse after above stated therapies.  A novel form of therapy known as percutaneous neuromodulation therapy has proven to be very beneficial in the treatment of this condition.

Advanced Pain Medicine