TRIGEMINAL NEURALGIA (tic douloureux)

• Trigeminal neuralgia (TN) presents as a stabbing unilateral facial pain that is triggered by chewing or similar activities or by touching affected areas on the face. The disorder affects the right side of the face 5 times more frequently than the left.
• Pain localization

Patients can localize their pain precisely. The pain is not confined exclusively to 1 of the 3 divisions of the trigeminal nerve but more commonly runs along the line dividing either the mandibular and maxillary nerves or the mandibular and ophthalmic portions of the nerve. Of affected patients, 60% complain of lancinating pain shooting from the corner of the mouth to the angle of the jaw; 30% experience jolts of pain from the upper lip or canine teeth to the eye and eyebrow, sparing the orbit itself—this distribution falls between the division of the first and second portions of the nerve. According to Patten, less than 5% of patients experience ophthalmic branch involvement.

• Pain quality

The pain quality is characteristically severe, paroxysmal, and lancinating. It commences with a sensation of electrical shocks in an affected area, then quickly crescendos in less than 20 seconds to an excruciating discomfort felt deep in the face, often contorting the patient's expression. The pain then begins to fade within seconds, only to give way to a burning ache lasting seconds to minutes. During attacks, patients may grimace, wince, or make an aversive head movement, as if trying to escape the pain, thus producing an obvious movement, or tic; hence the term "tic douloureux."

• Pain chronicity and frequency

This condition is an exception to the rule that nerve injuries typically produce symptoms of constant pain and allodynia. If the pain is particularly frequent, patients may be difficult to examine during the height of an attack. The number of attacks may vary from less than 1 per day, to a 12 or more per hour, up to hundreds per day.

• Pain triggers and zones

A valuable clue to the diagnosis is the triggering of the pain with certain activities. Patients carefully avoid rubbing the face or shaving a trigger area, in contrast to other facial pain syndromes, in which they massage the face or apply heat or ice. Also, many patients try to hold their face still while talking to avoid precipitating an attack. According to Sands, trigger zones, or areas of increased sensitivity, are present in one half of patients and often lie near the nose or mouth.^[15] Chewing, talking, smiling, or drinking cold or hot fluids may initiate the pain of trigeminal neuralgia. Touching, shaving, brushing teeth, blowing the nose, or encountering cold air from an open automobile window may also elicit pain.

In contrast to migrainous pain, persons with this condition rarely suffer attacks during sleep, which is another key point in the history.

• Treatment

Trigeminal neuralgia is treated on an outpatient basis, unless neurosurgical intervention is required. Management of this condition must be tailored individually, based on the patient's age and general condition. In the case of symptomatic trigeminal neuralgia, adequate treatment is that of its cause, the details of which are out of the scope of this article.

Because most patients incur trigeminal neuralgia when older than 60 years, medical management is the logical initial therapy. Medical therapy is often sufficient and effective, allowing surgical consideration only if pharmacologic treatment fails. Medical therapy alone is adequate treatment for 75% of patients.

Patients may find immediate and satisfying relief with one medication, typically carbamazepine. However, because this disorder may remit spontaneously after 6-12 months, patients may elect to discontinue their medication in the first year following the diagnosis. Most must restart medication in the future. Furthermore, over the years, they may require a second or third drug to control breakthrough episodes and finally may need surgical intervention.

Thus, treatment can be subdivided into pharmacologic therapy, percutaneous procedures, surgery, and radiation therapy. Adequate pharmacologic trials should always precede the contemplation of a more invasive approach.
So effective drugs are-

1. Carbamazepine-A 100-mg tablet may produce significant and complete relief within 2 hours, and, for this reason, a 100 mg twice a day (bid) prescription is suitable to start. If this initial dose fails, one may push the dose to 1200 mg daily (qd), as the patient will tolerate, for initial relief; maintenance doses generally are lower, 100-800 mg daily bid. 
2. Baclofen(musscle relaxant) 10mg B.D
3. Amitryptiline(Tricyclic anti depressant) 50-200mg/day
4. Gabapentin -Small, uncontrolled studies have indicated possible effectiveness of gabapentin in patients whose pain has become refractory to carbamazepine. This agent is often better tolerated than carbamazepine by elderly patients.