Radiosurgery for Secondary Trigeminal Neuralgia: Revisiting the Treatment Paradigm

Abstract

The mechanisms by which surgery and radiation elicit pain relief in trigeminal neuralgia (TN) secondary to mass lesions vary widely. We aimed to evaluate the outcomes of radiation to the nerve rather than to the lesion in the treatment of secondary TN. We retrospectively reviewed all patients who underwent radiation at the University of California, Los Angeles for TN secondary to tumors. The Barrow Neurological Institute (BNI) pain score was used to evaluate pain outcomes. Twelve patients were identified; 4 were male and 8 were female. Their mean age at treatment was 59.8 years (range, 47.7-84.7 years). Tumor pathologies included meningioma (n= 8), squamous cell carcinoma (n= 2), vestibular schwannoma (n= 1), and hemangiopericytoma (n= 1). No patient suffered from multiple sclerosis. Ten patients underwent initial radiation targeting their tumors-radiosurgery in 3 and fractionated radiation therapy in 7 others. Only 6 among these 10 experienced at least partial relief, which lasted a mean 6 months. Radiosurgery targeting the trigeminal nerve was eventually performed. Overall, 10 of 12 (83.3%) patients experienced good initial pain relief, complete in 6 (50%) patients. Pain recurred in 6 (60%) patients, at a mean 41 months after radiosurgery to the trigeminal nerve. Three patients experienced facial sensory dysfunction postprocedurally at a mean follow-up duration of 57 months. In contrast to tumor radiation, radiosurgery to the trigeminal nerve root resulted in reasonable and longer pain reduction, on par with the literature regarding surgical resection, with low risk of additional complications.