Trigeminal Neuralgia



What is Trigeminal neuralgia?

Trigeminal neuralgia (TN) is a chronic pain condition that affects the trigeminal or fifth cranial nerve, one of the largest nerves in the head. The disorder causes extreme, sporadic, and sudden burning or shock-like pain on the face that can last anywhere from a few seconds to as long as two minutes per episode. These attacks can occur in quick succession, and are usually described as manifeting around the area of the lower face and jaw. The pain is usually limited to one side of the face. The intensity of pain can be physically and mentally incapacitating, but it is not a life-threatening disorder. The presumed cause of TN is a blood vessel pressing on the trigeminal nerve in the head as it exits the brainstem, where it branches out to the forehead, cheek, and lower jaw. TN may be part of the normal aging process but in some cases it may be associated with other disorders, such as multiple sclerosis or disorders characterized by damage to the myelin sheath that covers certain nerves.

What are the symptoms of Trigeminal Neuralgia?

TN is characterized by a sudden, severe, electric shock-like, stabbing pain that is typically felt on one side of the jaw or cheek. Some patients say the first attack comes out of nowhere; others report that they first felt it after a car accident, blow to the face, or other trauma. Whatever its origin, it is described by some as the most agonizing pain known to humankind. The slightest breeze can trigger TN, or simply day-to-day activities such as brushing teeth, smiling, or applying make-up. The pain can occur on both sides of the face, although typically not at the same time. The attacks of pain, which generally last several seconds and may repeat in quick succession, coming and going throughout the day. These episodes may last for days, weeks, or months at a time and then disappear for months or years. In the days before an episode begins, some patients report experiencing a tingling or numbing sensation or a somewhat constant and aching pain. Once the episode is over, the pain often leaves patients with uncontrollable facial twitching, which is why the disorder is also known as tic douloureux.

The pain of trigeminal neuralgia is defined as either classic or atypical (also known as “TN-2″). With classic pain, there are definite periods of remission. The pain is intensely sharp, throbbing and shock-like, and usually triggered by touching an area of the skin, or by specific activities. Atypical pain is often present as a constant, burning sensation affecting a more diffuse area of the face. With atypical trigeminal neuralgia, there may not be a remission period, and symptoms are usually more difficult to treat.

How is Trigeminal Neuralgia diagnosed?

Trigeminal neuralgia can be difficult to diagnose due to the absence of definitive diagnostic tests as well as the wide variety of conditions that can trigger pain. The diagnosis of TN is essentially clinical; a physician must be well-trained to recognize key words in patients’ descriptions of symptoms. Above all, your doctor should be able to differentiate TN pain from the many other types of facial pain. Finding the cause of the pain is very important, because treatment differs depending on the type of pain. Other types of facial pains that could lead to an incorrect diagnosis include atypical facial pain, herpetic neuralgia, atypical odontalgias, cluster headaches, and other types of entrapments of the trigeminal nerve by post-tramatic conditions or tumors. Some patients may have tumors, and the well-known blood vessel compressing the trigeminal nerve along its course from the ganglion to the brainstem.

One of the tools Dr. Berti uses in diagnosing TN is magnetic resonance imaging (MRI). The MRI may detect whether a tumor or multiple sclerosis is irritating the trigeminal nerve; however, unless either of these is the cause, imaging of the brain will seldom reveal the precise reason the nerve is being irritated. The blood vessel adjacent to the nerve root is difficult to see even on a high quality MRI. Physicians diagnose patients based on patients’ descriptions of pain and symptoms, as well as a battery of tests that rule out other sources of pain, including multiple sclerosis. Thus, it is immensely important to find a physician who has extensive experience in treating TN, due to the difficulty in diagnosing it.

How is Trigeminal Neuralgia treated?

Although it is not a life-threatening disorder, TN can be debilitating and cause people to miss multiple days of work as well as important moments in their lives. Dr. Berti strives to take care of his patients with a multi-modality approach. Patients suffering from TN have several options available to them, including medication, surgery, complementary or alternative therapies, and stereotactic radiosurgery. Dr. Berti will explore all treatment options with his patients based on their comfort level, health, age, and comorbidities to create a treatment plan that works best for them.

Some of the more common medications prescribed for TN include anticonvulsants and tricyclic antidepressants, or medications such as Carbamazepine, Baclofen, Phenytoin, and Oxcarbazepin. If the medications become ineffective, or if the patient experiences serious side effects, he or she may be eligible for surgery. Surgery can be beneficial to some, and may be performed on an outpatient basis or may be more complex and require hospitalization. Dr. Berti may recommend miscrovascular decompression (MVD), a surgical procedure that will relieve the compression of the trigeminal nerve. MVD of the trigeminal nerve is performed via a retromastoid approach, where the trigeminal nerve is separated from the vessel that is compressing it with a sponge, usually at the entry root zone or the area close to the brain stem where there are less or no oligodendrical cells that cover the nerve. This area is where the brain may interpret any sensations as electrical shocks. Microvascular decompression has an approximately 80% succeess rate at two years after surgery

A patient with TN who has difficulty tolerating medications, or who has pain despite these medications, is an excellent candidate for stereotactic radiosurgery such as Gamma Knife or CyberKnife radiosurgery. Stereotactic radiosurgery computer imaging is used to direct highly focused beams of radiation at the site where the trigeminal nerve exits the brainstem. This causes the slow formation of a lesion on the nerve that disrupts the transmission of pain signals to the brain. While patients usually leave the hospital the same day or the next day following treatment, pain relief from this procedure may take several months to manifest. Dr. Berti has had excellent results with CyberKnife radiosurgery, offering an 80% success rate with the control of facial pain. Patients who have opted for CyberKnife treatment have either stopped taking medications or their medications have become more effective as they take them. Patients also have the option of alternative or complementary approaches such as biofeedback, acupuncture, and electrical stimulation of the nerves.

“Studies have shown that: Excellent pain relief was initially experienced by 64 out of 95 patients (67%). The median time to pain relief was 14 days (range, 0.3-180 d). Posttreatment numbness occurred in 45 (47%) of the patients treated. Using higher radiation doses and treating longer segments of the nerve led to both better pain relief and a higher incidence of hypesthesia. The presence of posttreatment numbness was predictive of better pain relief. The overall rate of complications was 18%. At the mean follow-up time of 2 years, 47 of the 95 patients (50%) had sustained pain relief, all of whom were completely off pain medications.”