Trigminal Neuralgia

Trigeminal neuralgia is characterized by sudden outburst or attacks of extreme pain strictly restricted to the area of distribution of the trigeminal nerve. Nicolaus Andre coined the term “Tic Douloureux” in 1756. It means painful jerking of the nerve. Trigeminal neuralgia (TN) is one of the most painful conditions known to medical scientists & is basically disorder of 5th cranial nerve. The disorder involves sudden severe pain on one side of the face usually caused by a blood vessel or any other lesion pressing on the nerve.” 

Trigeminal neuralgia is uncommon, but the pain is unbearable. The trigeminal nerve, which provides sensation to the face, is identified as one of the 12 pairs of cranial nerves. One trigeminal nerve runs to the right side of the head, and the other runs to

the left side. Each of these nerves has three distinct branches. The first branch controls sensation to the eye, forehead and nose; the second controls the lower lid, side of the nose, upper teeth, gums, lip and cheek; and the third supplies sensation to the lower teeth, gum, lip and jaw.

Incidence Annual occurence rate of TN is 3-5 per 100,000 people. It is found more often in women than men (Age adjusted ratio 1.74:1) & most common age group is 52- 69 years. It is also seen in younger patient & is known as secondary TN. Attacks occur during the day or night but rarely during sleep (2). 
Pain is usually unilateral in 97% cases, affects maxillary & mandibular branches which means the patient has severe pain around the nose or going right upto mandible. In some cases, pain of TN can be bilateral (3%) & invariably same nerve divisions (V2 and V3) are affected. Right side of face being affected in 57% cases (2). 

Pain experienced from trigeminal neuralgia usually affects the lower face and jaw, though sometimes it occurs near the nose and above the eye. The intense, stabbing, electric like pain is caused by irritation of the trigeminal nerve. Common causes of trigeminal neuralgia include: pressure of a blood vessel on the root of the trigeminal nerve; physical damage to the nerve caused by dental or surgical procedures; injury to the face; or in many cases, there are absolutely no clear causes of the disorder. Pain attacks are often triggered by a light touch of the skin such as applying makeup, eating, washing, shaving, brushing the teeth, blowing the nose, drinking hot or cold drinks, a light breeze and even smiling. The pain of trigeminal neuralgia is characterized as either “classical” or “atypical.” With classic pain, there are
clear periods of remission, although the pain is intensely sharp, throbbing and shock-like. Atypical pain is also a sharp stabbing pain, but patients additionally experience burning, pulsating or crushing sensations, and often do not have a period of remission. Some patients suffer less than one pain attack per day, while others experience 12 or more each hour. The pain typically initiates with a series of electrical shocks that culminate in less than 20 seconds, with an excruciating stabbing pain. Patients will suffer long stretches of frequent attacks followed by weeks, months or even years of virtually little or no pain. Over time however, the tendency is for the attacks of pain to intensify with shorter “pain-free” periods. 
Surgery can be an effective option for those patients who become unresponsive to medications or those who experience serious side effects from the medications. Fortunately, about 85 percent of patients who undergo surgery experience significant pain relief. The two most common are microvascular decompression and percutaneous neurolysis. Both surgical procedures are more effective when initiated in the early stages of the disorder. Vascular decompression can offer many years of pain relief. In this operation, a neurosurgeon will make
an incision in the back of the head to expose the trigeminal nerve at the base of the brain. The pad is then inserted between the nerve and the blood vessels to alleviate compression. Percutaneous techniques are performed in a variety of ways that include: using a needle to pass through the skin and lesion the trigeminal nerve; radiofrequency energy to burn the nerve, use of a balloon to destroy the nerve compressing it, or through use of chemicals to damage the nerve. These techniques allow relief of trigeminal neuralgia by destroying the pain fibres of the trigeminal nerve, which may also make the area of pain permanently numb. The procedure takes less than one hour, and patients are usually free to go home the same day. Most patients can fully return to work within a few days. Patients who undergo percutanous treatment can expect to have relief from their pain for a few years. After that time, if necessary, and recommended by a physician, the procedure can be repeated. 

Neurosurgeons provide the operative and nonoperative (prevention, diagnosis, evaluation, treatment, critical care and rehabilitation) care of neurological disorders.

Each type of surgery carries with it potential benefits as well as risks of complications or long-term side effects. Thus, one must select the type of surgery carefully, with a complete understanding of all possible outcomes. The results of any procedure are known to be dependent upon the experience, expertise, and specific techniques unique to the neurosurgery team. These important variables must be taken into account when selecting a treatment.

Surgical Interventions
The goal of the surgery is to either damage or destroy the path of trigeminal nerve which is the basic cause of pain.

Microvascular Decompression Surgery alleviates neurovascular compression by placing inert shredded Teflon® felt implants between offending vessels and the trigeminal nerve root.
Percutaneous Rhizotomies involve inserting a needle through the cheek and into an opening at skull base (foramen ovale). 
There, a controlled injury to the trigeminal nerve and Gasserion ganglion may be produced in one of three ways:
Percutaneous Glycerol Injection - glycerol is injected into the space around the Gasserion ganglion, and chemically damages the nervous tissue.
Percutaneous Balloon Compression Rhizotomy - a balloon is inflated next to the Gasserion ganglion, compressing and mechanically damaging the nervous tissue.
Radiofrequency Rhizotomy - an electrode is advanced into the Gasserion ganglion, and heated to thermally damage the nervous tissue.
Peripheral Trigeminal Nerve Blocks, Sectioning and Avulsions involve injuring the peripheral portions of the trigeminal nerve external to the skull.
Microsurgical Rhizotomy involves surgical exposure and cutting of the trigeminal nerve root near its entry into the brain stem.