Trigeminal neuralgia (TN), sometimes referred to as Tic Douloureux, is a nerve disorder that can cause intense pain on either side of the face. The pain can be triggered when cold air touches specific facial areas or with movements like chewing, talking or swallowing. The disorder occurs in the trigeminal, or fifth cranial, nerve that controls sensation in the face. TN is more common in women, and patients are typically middle-aged or seniors. The unpredictable, severe pain from TN makes it emotionally incapacitating and can significantly impact one’s quality of life.
TN patients are divided into typical and atypical cases. In typical TN, patients suffer from unpredictable episodes of stabbing, electric shock-like pain in a constant location of the face. Such patients can reproduce an attack by touching a “trigger point” on the face or performing a specific activity like chewing or talking. With atypical TN, the pain is a persistent dull ache or burning sensation in one part of the face. However, episodes of sharp pain can complicate atypical TN. There is usually not a specific trigger point with atypical TN, while the pain grows worse over time.
TN is usually related to compression of the trigeminal nerve by a blood vessel. It can arise suddenly and last several years and even decades. The number of attacks can be seasonal and vary from several each day to a few each year.
What are the treatment options?
TN is treated with medication, surgery or radiosurgery, all of which offer varying degrees of success. Medication can relieve pain in most TN patients, though it’s not always effective and can produce fatigue or other significant side effects. Nevertheless, medication is generally the first line of treatment.
If patients fail multiple medical treatments, they’re offered surgery, including a procedure known as microvascular decompression, or MVD. In younger TN patients, MVD is often preferred, because it holds the potential of a long-term cure without causing significant facial numbness.
Other procedures known as radiofrequency rhizotomy, glycerol rhizotomy or nerve balloon compression attempt to destroy trigeminal nerve fibers that cause pain. These operations have varying degrees of success, and pain relief often doesn’t last more than a few years. Therefore, the treatment is typically repeated several times over a patient’s life.
Open surgery also carries risks of infection, arterial or cranial-nerve injury or stroke. Certain patients have medical conditions that prevent surgery, while others may object to surgery.
Radiosurgery focuses radiation beams on the trigeminal nerve to essentially cut pain-causing fibers. Initially, such treatment was administered only with systems that required attaching a rigid metal frame to the patient’s skull under local anesthesia. CyberKnife doesn’t require a head frame. It uses a highly advanced computer-imaging system that can compensate for small head movements, allowing the patient to lie comfortably during the procedure.
TN treatment with the CyberKnife begins with a CT or MRI brain scan, particularly of the trigeminal nerve area. With a CT scan, doctors often use a dye injected into the spinal fluid through a spinal tap to improve the imaging.
During CyberKnife treatment, high-dose radiation beams are precisely aimed along a segment of the trigeminal nerve. CyberKnife treatments for TN usually take a little more than an hour.
Up to 80 percent of TN patients treated with the CyberKnife experience significant and lasting pain relief. The most common side effect is facial numbness that likely correlates with the degree of pain relief. Moreover, pain relief with CyberKnife treatment can be substantially faster than other forms of radiosurgery. This may be the result of the system’s accuracy. Follow-up is needed before doctors can estimate how long pain relief will last.