Repeat trigeminal nerve radiosurgery for refractory cluster headache fails to provide long-term pain relief

Objective/Background.-Medically refractory cluster headache (MRCH) is a debilitating condition that has proven resistant to many modalities. Previous reports have indicated that radiosurgery for MRCH provides little long-term pain relief, with moderate/significant morbidity. However, there have been no reports of repeated radiosurgery in this patient population. We present our findings from the first reports of repeat radiosurgery for MRCH. Methods.-Two patients with MRCH underwent repeat gamma knife radiosurgery at our institution. Each fulfilled clinical criteria for treatment, including complete resistance to pharmacotherapy, pain primarily localized to the ophthalmic division of the trigeminal nerve, and psychological stability. Both patients previously received gamma knife radiosurgery (75 Gy) for MRCH with no morbidity, but no long-term improvement of pain relief (Patient 1 = 5 months, Patient 2 = 10 months) after treatment. For repeat radiosurgery, each patient received 75 Gy to the 100% isodose line delivered to the root entry zone of the trigeminal nerve, and was evaluated postretreatment. Pain relief was defined as: excellent (free of MRCH with minimal/no medications), good (50% reduction of MRCH severity/frequency with medications), fair (25% reduction), or poor (less than 25% reduction). Results.-Following repeat radiosurgery, long-term pain relief was poor in both patients. Neither patient sustained any immediate morbidity following radiosurgery. Patient 2 experienced right facial numbness 4 months postretreatment, while Patient 1 experienced no morbidity. Conclusion.-Repeat radiosurgery of the trigeminal nerve fails to provide long-term pain relief for MRCH. Given the reported failures of initial and repeat radiosurgery for MRCH, trigeminal nerve radiosurgery should not be offered for MRCH.