Trigeminal Neuralgia (TN)
Trigeminal neuralgia (TN), also known as tic doloureux, is a chronic neuropathic disorder characterized by episodes of intense pain in the face.
The trigeminal nerve is one of the 12 paired cranial nerves. The trigeminal nerve (CN V) is a paired cranial nerve that has three major branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3).
The ophthalmic branch controls sensation in a person’s eye, upper eyelid and forehead. The maxillary branch controls sensation in the lower eyelid, cheek, nostril, upper lip and upper gum. The mandibular branch controls sensations in the jaw,lower lip, lower gum and some of the muscles used for chewing.
Any or all three branches of the nerve may be affected causing intense and excruciating facial pain.
According to the literature, 1–6% of cases occur on both sides of the face but it is extremely rare for both to be affected at the same time.
The incidence is 12.6 per 100,000 person in the USA. The prevalence is 155 cases/1,000,000 in the USA.Trigeminal neuralgia most commonly involves the middle branch (the maxillary nerve or V2) and lower branch (mandibular nerve or V3) of the trigeminal nerve.
Trigeminal neuralgia affects women more often than men, and it’s more likely to occur in people who are older than 50.
This disorder is characterized by episodes of intense facial pain.
Each individual attack of pain lasts from a few seconds to several minutes or hours, but these can repeat for hours with very short intervals between each attack.
Most patients report that their pain begins spontaneously and seemingly out of nowhere. Other patients reported pain following a car accident, a blow to the face or dental surgery.
Pain often is first experienced along the upper or lower jaw, so many patients assume they have a dental problem.
There are two types of pain associated with trigeminal neuralgia.
It is either classic or atypical. With classic pain, there are periods of remission. The pain is intensely sharp, throbbing, and sometimes described as shock-like. It is usually triggered by touching an area of the skin or by specific activities.
Atypical pain is a constant and burning sensation affecting a more widespread area of the face. With atypical trigeminal neuralgia, there may not be a remission period, and symptoms are usually more difficult to treat.
The pain tends to run in cycles.
The pain typically begins with a sensation of electrical shocks which results in an excruciating stabbing pain within less than 20 seconds. The pain often leaves patients with uncontrollable facial twitching, which is why the disorder is also known as tic douloureux.
The attacks of trigeminal neuralgia may be triggered by touching the skin lightly, shaving, washing the face, brushing teeth, blowing the nose, drinking hot or cold beverages, experiencing a light breeze, application of makeup, smiling, and talking. Individuals with hypertension or multiple sclerosis have increased risk for trigeminal neuralgia.
Magnetic Resonance Imaging (MRI) can be used to visualize if a tumor or multiple sclerosis is irritating the trigeminal nerve.
There are many medications used in the treatment of trigeminal neuralgia. They include:Carbamazepine (Tegretol), Baclofen (Lioresal), Phenytoin (Dilantin), and Oxcarbazepine (Trileptal). Other medications include gabapentin (Neurontin), clonazepam (Klonopin), sodium valproate (Depakote), and lamotrigine (Lamictal).
There are several surgical procedures that may help control the pain associated with trigeminal neuralgia.
Surgical treatment is divided into two categories: percutaneous (through the skin) and open. In general, percutaneous approaches are preferred in older patients and those who have not achieved pain relief from the open approach. The open approach is recommended for younger and healthier patients.
Microvascular decompression involves the microsurgical exposure of the affected trigeminal nerve root.
The nerve may be compressed by a blood vessel (artery or vein). The blood vessel is gently moved away from the point of compression. This procedure may reduce sensitivity and allow the trigeminal nerve to improve and return to normal function. This is the most effective surgery.
Percutaneous stereotactic rhizotomy treats trigeminal neuralgia through the use of heat. The surgeon passes a hollow needle through the cheek into the trigeminal nerve. Heat destroys the nerve fibers. Another surgical procedure is percutaneous glycerol rhizotomy. It utilizes glycerol. The goal is to selectively damage the trigeminal nerve in order to interfere with the transmission of the pain signals to the brain.
Another procedure involves a needle that is passed through the cheek to the trigeminal nerve. The neurosurgeon places a balloon in the trigeminal nerve through a catheter. The balloon is inflated and compresses the nerve which in turn injures the pain-causing fibers.
The last procedure I would like to discuss is stereotactic radiosurgery. This is better known as the Gamma Knife. This procedure delivers a single highly concentrated dose of ionizing radiation to a small, precise target. There is a slow formation of a lesion in the nerve which interrupts transmission of pain signals to the brain. There is no guarantee that surgery will help every individual.
Trigeminal neuralgia is characterized by exacerbations and remissions.
This condition is not fatal.
Medications and/or surgery can be helpful. As always, early diagnosis is important for the best outcome.
If you suspect trigeminal neuralgia, please call and consult with your doctor or go to the nearest emergency room for treatment.
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