The initial therapy for individuals with TN is usually the use of medications, particularly the anti-seizure medications (anti-convulsants), carbamazepine or oxycarbazepine. When used in the early stages, these drugs are generally effective in reducing pain of affected individuals. Most people begin with a low dose that is gradually increased until the pain goes away. The exact dosage needed for each individual will vary. Despite its initial effectiveness, the benefits of these drugs may lessen over time. As with most drugs, carbamazepine can be associated with side effects. Oxycarbazepine, which is a newer medication that is related to carbamazepine, is generally associated with fewer side effects than carbamazepine.
Additional anti-seizure medications that have been used to treat TN in smaller studies or case reports include topiramate, gabapentin, pregabalin, clonazepam, phenytoin, lamotrigine, and valproic acid.
Over time, in many cases, these drugs may become less effective or ineffective. When one anti-seizure drug loses effectiveness, another anti-seizure medication may be tried. More than one anti-seizure medication may be necessary to control pain in an affected individual. Eventually, anti-seizure medications may stop providing relief.
Muscle relaxants, such as baclofen, may also be used. Such medications may be used alone or in conjunction with anti-seizure medication. Tricyclic antidepressant medications such as amitriptyline and nortriptyline can dampen pain transmission in individuals with TN2. Common pain relievers such as opioids are generally ineffective in TN1, but may provide some relief in TN2.
If medications fail to control pain or become ineffective, surgery is recommended. There are several different surgical techniques that have been used to treat individuals with TN. Surgical techniques are generally not used unless other therapies have failed or become ineffective. The decision to undergo surgery to treat TN can depend on several factors. Some physicians and individuals in the TN community believe that surgical interventions should occur sooner rather than later. There is evidence that affected individuals have a better response to microvascular decompression if the surgery is done within seven years of the initial diagnosis rather than later. Surgery should be considered early in an individual who does not have an adequate response to the two front-line medications, whether these medications are used in succession or in combination. An inadequate response can be defined as incomplete pain relief affecting activities of daily living or requiring such high doses of medication to relieve the pain that the side effects limit functioning.
Decisions concerning the use of a particular surgery, drug regimens, and/or other treatments should be made by physicians and other members of the health care team in careful consultation with parents or a patient based upon the specifics of the individual case; a thorough discussion of the potential benefits and risks, including possible side effects and long-term effects; patient preference; and other appropriate factors.
One of the most common procedures to treat TN1 is microvascular decompression, also known as the Janetta procedure. This procedure involves moving the blood vessel that is pressing against the trigeminal nerve and inserting a soft cushion between the nerve and the vessel. This allows the trigeminal nerve to recover, eventually relieving the pain. Microvascular decompression can result in sustained pain relief of greater than 10 years in some cases. This procedure is the only non-destructive one that will leave trigeminal nerve function intact, but the procedure is the most invasive and carries a small risk of serious complications. During the procedure, the physician makes a small incision behind the ear on the same side of the head where the pain is located and creates a small hole in the skull to gain access the trigeminal nerve and the blood vessels that are compressing it.
Another possible treatment is stereotactic surgery, which includes procedures known as Gamma Knife and CyberKnife. These procedures employ a highly concentrated beam of ionizing radiation that is delivered to a specific target at the root of the trigeminal nerve. The radiation creates a lesion near the nerve root that disrupts the transmission of pain signals to the brain. Pain relief may be delayed, however, by up to several weeks or months. Additionally, in approximately 50% of individuals, pain returns within three years. These procedures are the least invasive surgical techniques for treating individuals with TN and can be repeated if pain recurs.
Three additional procedures involve damaging the trigeminal nerve to interrupt the transmission of pain signals to the brain. These procedures are percutaneous balloon compression, percutaneous glycerol rhizotomy, and percutaneous stereotactic rhizotomy. They involve the insertion of a needle through the cheek and into the trigeminal nerve. Percutaneous balloon compression involves inserting a tiny balloon in the trigeminal nerve near the area where the pain fibers are located. The balloon is inflated, damaging the nerve fibers. Then the balloon is deflated and removed. Percutaneous glycerol rhizotomy involves injecting glycerol, a chemical compound, into the trigeminal nerve to damage the nerve. Percutaneous stereotactic rhizotomy, also known as radiofrequency lesioning, involves uses an electrode to apply heat to damage nerve fibers.