Gamma Knife radiosurgery is the most recent and least invasive neurosurgical treatment for trigeminal neuralgia (TN), a condition that is characterized by sudden bursts (paroxysms) of face pain. These bursts are often triggered by a light touch around the mouth or face or by talking, eating, or brushing one's teeth. Approximately 14,000 people develop TN each year in the United States, and it is more common in patients with multiple sclerosis.
The cause of trigeminal neuralgia is not always certain. Approximately five percent of patients have a tumor pressing on the trigeminal nerve where it leaves the brain, while other patients have a blood vessel that presses on the trigeminal nerve, close to the brain. In some patients the cause cannot be determined. Approximately five percent of patients with trigeminal neuralgia have multiple sclerosis. Patients with TN and multiple sclerosis are generally younger, and tend to first experience TN symptoms while in their mid 40s. Patients who have TN but not multiple sclerosis tend to first experience TN symptoms while in their mid 50s.
There are five important neurosurgical procedures. Each is effective, but not always, and occasionally has to be repeated.
Gamma Knife radiosurgery
Radiofrequency electrocoagulation
Glycerol injection
Balloon microcompression
Microvascular decompression
All of these procedures treat the trigeminal nerve at around the same place, close to where it leaves the brain. Of all the surgical procedures, Gamma Knife radiosurgery is least likely to cause complications and uncomfortable new facial sensations (dysesthesias).
Any patient with trigeminal neuralgia who has pain or has difficulty with the medicines used to relieve the pain is an excellent candidate for Gamma Knife radiosurgery. Even the elderly or medically infirm can undergo this treatment. Those who have had previous procedures for TN may also undergo Gamma Knife treatment.
Approximately 85 to 90 percent of patients experience excellent or good pain relief following Gamma Knife treatment. Patients may experience pain relief one day to four months after the procedure. About half of patients will experience pain relief within four weeks. Older series reported pain recurrence within three years in 20-40% percent of patients. With current techniques, the recurrence should be less. Patients with TN and multiple sclerosis are less likely to respond to GKRS than those without multiple sclerosis, although they also may be helped by the procedure. Gamma Knife radiosurgery can be repeated, but not until at least four months after the original procedure.
Gamma Knife radiosurgery is a major advance in the treatment of trigeminal neuralgia, offering a procedure designed to relieve pain fewer complications.
