Effectiveness of Gamma Knife Radiosurgery in the Treatment of Refractory Trigeminal Neuralgia: A Case Series

BACKGROUND: Medicalmanagement is the first line of treatment for trigeminal neuralgia ( TN). Patients with medically refractory TN may undergo a variety of invasive surgical interventions with varying success rates. Management of TN refractory to both medical and surgical intervention remains somewhat controversial. OBJECTIVE: To assess the effectiveness of Gamma Knife radiosurgery (GKRS; Elekta Instruments AB) for medically refractory TN. METHODS: A retrospective review was conducted for 57 cases (47 patients) who underwent GKRS for refractory TN at our institution between 2005 and 2018. TN pain outcomes were evaluated using the Barrow Neurological Institute (BNI) Pain Scale. A good outcomewas defined by post- GKRS BNI score of I-III, whereas treatment failure was defined BNI score IV-V. RESULTS: Of the total 57 GKRS procedures, 47 (82.5%) had good outcomes. A total of 22 patients (46.8%) experienced complete pain relief offmedications (BNI I). The average time to pain relief was 30 d (range 1-120 d). Prior invasive surgical treatment for TNwas not found to have a significant impact on GKRS outcomes (P =.32). Target and treatment volumes were not found to correlate significantly with GKRS outcomes (.47 and.47, respectively). Complications included 2 cases (4.2%) of facial numbness. A total of 37 patients (78.7%) did not have any additional invasive surgical interventions following GKRS treatment. CONCLUSION: GKRS is a safe and effective treatment modality for both medically and surgically refractory TN. Complete symptom relief was possible in patients with prior surgical or GKRS treatments. Recurrent symptoms following surgery or GKRS should not exclude a patient from future GKRS consideration.