Salvage gamma knife stereotactic radiosurgery for surgically refractory trigeminal neuralgia.

PURPOSE: To evaluate the clinical outcome of patients with surgically refractory trigeminal neuralgia (TN) treated with rescue gamma knife radiosurgery (GKRS). METHODS AND MATERIALS: Seventy-nine patients with typical TN received salvage GKRS between 1997 and 2002 at the Barrow Neurological Institute (BNI). All patients had recurrent pain following at least one prior surgical intervention. Prior surgical interventions included percutaneous destructive procedures, microvascular decompression (MVD), or GKRS. Thirty-one (39%) had undergone at least two prior procedures. The most common salvage dose was 80 Gy, although 40-50 Gy was typical in patients who had received prior radiosurgery. Pain outcome was assessed using the BNI Pain Intensity Score, and quality of life was assessed using the Brief Pain Inventory. RESULTS: Median follow-up after salvage GKRS was 5.3 years. Actuarial analysis demonstrated that at 5 years, 20% of patients were pain-free and 50% had pain relief. Pain recurred in patients who had an initial response to GKRS at a median of 1.1 years. Twenty-eight (41%) required a subsequent surgical procedure for recurrence. A multivariate Cox proportional hazards model suggested that the strongest predictor of GKRS failure was a history of prior MVD (p=0.029). There were no instances of serious morbidity or mortality. Ten percent of patients developed worsening facial numbness and 8% described their numbness as "very bothersome." CONCLUSIONS: GKRS salvage for refractory TN is well tolerated and results in long-term pain relief in approximately half the patients treated. Clinicians may reconsider using GKRS to salvage patients who have failed prior MVD.

Long-term pain response and quality of life in patients with typical trigeminal neuralgia treated with gamma knife stereotactic radiosurgery.

OBJECTIVE: The long-term outcome of patients treated with gamma knife radiosurgery (GKRS) for typical trigeminal neuralgia has not been fully studied. We evaluated 185 patients who underwent their first GKRS treatment between 1997 and 2003 at the Barrow Neurological Institute. METHODS: Follow-up was obtained by surveys and review of medical records. Outcomes were assessed by the Barrow Neurological Institute Pain Intensity Score and Brief Pain Inventory. The most common maximum dose was 80 Gy targeted at the root entry zone. Outcomes are presented for the 136 (74%) patients for whom more than 4 years of clinical follow-up data were obtained. RESULTS: Treatment failed in 33% of the cohort within 2 years, but only an additional 1% relapsed after 4 years. Actuarial analysis demonstrated that 32% of patients were pain-free off medication and 63% had at least a good outcome at 7 years. When GKRS was used as the primary treatment, 45% of the patients were pain-free at 7 years. In contrast, 10% of patients in whom previous treatment had failed were pain-free. When needed, salvage therapy with repeat GKRS, microvascular decompression, or percutaneous lesioning was successful in 70%. Posttreatment facial numbness was reported as very bothersome in 5%, most commonly in patients who underwent another invasive treatment. After GKRS, 73% reported that trigeminal neuralgia had no impact on their quality of life. CONCLUSION: GKRS is a reasonable long-term treatment option for patients with typical trigeminal neuralgia. It yields durable pain control in a majority of patients, as well as improved quality of life with limited complications and it does not significantly affect the efficacy of other surgical treatments, should they be needed.