BACKGROUND: Trigeminal neuralgia is a disabling pain syndrome responsive to both medical and surgical therapies. Stereotactic radiosurgery using the gamma knife can be used to inactivate a specified volume in the brain by cross firing 201 photon beams. We evaluated pain relief and treatment morbidity after trigeminal neuralgia radiosurgery. METHODS: All evaluable patients (n = 106) had medically or surgically refractory trigeminal neuralgia. A single 4-mm isocenter of radiation was focused on the proximal trigeminal nerve just anterior to the pons. For follow-up an independent physician who was unaware of treatment parameters contacted all patients. RESULTS: After radiosurgery, 64 patients (60%) became free of pain and required no medical therapy (excellent result), 18 (17%) had a 50% to 90% reduction (good result) in pain severity or frequency (some still used medications), and 9 (9%) had slight improvement. At last follow-up (median, 18 months; range, 6-48 months), 77% of patients maintained significant relief (good plus excellent results). Only 6 (10%) of 64 patients who initially attained complete relief had some recurrent pain. Radiosurgery dose (70-90 Gy), age, surgical history, or facial sensory loss did not correlate with pain relief. Poorer results were found in patients with multiple sclerosis. Twelve patients developed new or increased facial paresthesias after radiosurgery (10%). No patient developed anesthesia dolorosa. There was no other procedural morbidity. CONCLUSIONS: Gamma knife radiosurgery is a minimally invasive technique to treat trigeminal neuralgia. It is associated with a low risk of facial paresthesias, an approximate 80% rate of significant pain relief, and a low recurrence rate in patients who initially attain complete relief. Longer-term evaluations are warranted.

Adult↗

PubMed1997

Gamma knife radiosurgery for trigeminal neuralgia.

Radiosurgery is one of the surgical treatments of trigeminal neuralgia. Through precise irradiation of the proximal trigeminal nerve identified on high-resolution imaging, pain relief can be achieved after a short latency interval. This image-guided approach has been useful for both patients with persistent pain after other surgeries, and as a primary surgical option. A minimum dose of 70 Gy delivered with the gamma knife has been associated with low risk for facial numbness, and no other morbidity. Management of trigeminal neuralgia without an incision, transfacial needle placement or nerve section may prove useful to increasing numbers of patients.

Humans↗

PubMed1996

Trigeminal neuralgia radiosurgery: the University of Pittsburgh experience.

The results of Gamma Knife stereotactic radiosurgery in the management of 51 patients who had typical trigeminal neuralgia were evaluated at the University of Pittsburgh. In all cases, a 4-mm isocenter was targeted at the proximal nerve at the root entry zone. The target dose varied from 60 to 90 Gy. Forty-four patients (86%) had undergone prior surgery. The mean follow-up after radiosurgery was 9.6 months (range, 2-29 months). The initial response rate was 86%. At the last follow-up, 19 patients (37%) had excellent control (pain free), 21 (41%) had good control (50-90% relief), and 11 (21%) had failed treatment. No patient developed further sensory loss or deafferentation pain. A maximum radiosurgery dose > or = 70 Gy was associated with a significantly greater chance for complete pain relief. Using magnetic resonance imaging stereotactic targeting, the proximal trigeminal nerve is an appropriate anatomic target for radiosurgery. Gamma Knife radiosurgery is a useful additional surgical approach in the management of medically or surgically refractory trigeminal neuralgia.

Adult↗