An Overview of Trigeminal Neuralgia in MS

Trigeminal neuralgia is a rare, painful condition caused by irritation of the fifth cranial nerve. It can be experienced by people with multiple sclerosis (MS) and may be one of the first symptoms of the disease. Demyelination—the loss of the myelin sheath surrounding nerve fibers—is what triggers this disorder in people with MS.

According to a 2017 study, approximately 4 percent of people with MS experience trigeminal neuralgia. People with MS are far more likely than the general population to have an episode of the disorder: in the latter population, the probability is 0.3 percent.

Signs and Symptoms

Trigeminal neuralgia, sometimes called tic doloureux (French for “painful twitch”), is perhaps the most intensely painful MS-related symptom.

The typical form of the disorder is called Type 1 (TN1), and it causes extreme, sporadic, sudden, electrical burning or shock-like pain that can last anywhere from a few seconds to two minutes. These attacks may occur in quick succession, last throughout a day, or wax and wane over the course of a day.

The atypical form of the disorder, called Type 2 (TN2), is characterized by constant aching, burning, and stabbing pain that is less intense than TN1 but still very painful.

Both forms may occur in the same person, sometimes at the same time. The pain can be so extreme that a person becomes physically and mentally incapacitated. 

The trigeminal nerve provides sensation to the face and part of the ear and forehead. Therefore, the pain in trigeminal neuralgia can occur in any region of the face. However, it is usually distributed in one of the main branches of the trigeminal nerve. The most common areas are known as V1, V2 and V3, and, most commonly, the pain occurs in the V1 region (which is over the forehead) or V2, which is in the cheek and ear area.

Each episode of trigeminal neuralgia usually lasts a couple of weeks. Episodes tend to recur and can happen as often as every couple of months, although some people will go years between episodes.

Causes

The pain is caused by lesions on or injury to the trigeminal nerve, which is also called the fifth cranial nerve. The twelve cranial nerves emerge directly from the brain (instead of from the spinal cord), and the trigeminal nerve controls the muscles needed for chewing. The trigeminal nerve is also responsible for most facial sensation.

A person can develop trigeminal neuralgia without having multiple sclerosis. In this instance, one can find changes in the trigeminal nerve root from vascular compression or no abnormalities at all. This type of trigeminal neuralgia is called classical trigeminal neuralgia.

When trigeminal neuralgia is caused by MS, it's referred to as secondary trigeminal neuralgia.

Diagnosis

A diagnosis of trigeminal neuralgia is based largely on a person’s history and description of symptoms, as well as on the results of a neurological examination. By touching and examining parts of your face, your healthcare provider can determine exactly where the pain is occurring and which branches of the trigeminal nerve may be affected. You may also undergo magnetic resonance imaging (MRI) of your head to determine if MS or a tumor is causing trigeminal neuralgia.

Because facial pain can be caused by many different conditions, other disorders should also be ruled out before trigeminal neuralgia is diagnosed. Other disorders that cause facial pain, for example, are post-herpetic neuralgia (nerve pain following an outbreak of shingles), cluster headaches, and temporomandibular joint disorder (TMJ), which causes pain and dysfunction in the jaw.

Trigeminal neuralgia is also often mistaken for dental pain. This can lead to unnecessary (and irreversible) procedures like tooth extractions, root canals, and even procedures to reposition the jaw.

Treatment

If you have trigeminal neuralgia, your healthcare provider may prescribe either Tegretol (carbamazepine) or Trileptal (oxcarbazepine) to ease symptoms.

Other medications may include:

• Baclofen, a muscle relaxant
• Lamictal (lamotrigine), an anti-seizure medication
• Tricyclic antidepressants such as Elavil (amitriptyline) or Aventyl (nortriptyline)
• An injection of Botox (botulinum toxin type-A) in areas of the head and neck called trigger zones

If medication fails to relieve pain or produces unpleasant side effects, surgical treatment may be indicated.

Several neurosurgical procedures are available to treat trigeminal neuralgia, depending on the nature of the pain and the distribution of trigeminal nerve involvement. Surgical options include:

• Microvascular decompression: With this procedure, a surgeon makes an incision behind the ear on the side of your pain, makes a small hole in your skull and moves away the vessel (usually an artery) that is compressing the nerve. Then a soft cushion is placed between the nerve and the vessel.
• Brain stereotactic radiosurgery (Gamma Knife or CyberKnife surgery): In this procedure, a surgeon directs a focused dose of radiation to the root of your trigeminal nerve to damage it and thus reduce or eliminate pain.
• Rhizotomy: This is a procedure in which nerve fibers are damaged to block pain. Several forms of rhizotomy are available to treat trigeminal neuralgia, all of which usually result in some degree of facial numbness and sensory loss.

Trigeminal neuralgia can get so severe and distressing that it may require hospitalization and intravenous painkillers. It can also interfere with your ability to drink fluids, so these sometimes have to be given intravenously as well.

A Word From Verywell

Aside from the physical distress trigeminal neuralgia causes, trigeminal neuralgia often results in psychological distress. Many people have anxiety and fear about the possibility of it recurring, which can cause significant suffering and interfere with daily life.

In addition to seeing your neurologist and taking medication (if needed), reaching out to a support group may also be beneficial for the psychological manifestations of trigeminal neuralgia.