Objectives To report on the outcome and follow-up of 7 medically intractable SUNCT and SUNA patients treated with ONS.

Background SUNCT and SUNA are primary headaches characterised by repeated attacks of very severe headaches in association with cranial autonomic features that usually occur several times daily. They can be medically intractable, in which case neurally destructive or cranially invasive treatments can be offered. ONS offers a nondestructive and relatively low-risk surgical alternative.

Methods Seven medically intractable patients (6 SUNCT, 1 SUNA) had bilateral ONS implants. Data were collected retrospectively for demographics, diagnosis, previous treatments, ONS settings, preimplantation and postimplantation headache characteristics, patients' estimates of change in headaches and complications.

Results At a median follow-up of 24 months (range 4–29), four patients reported a substantial improvement (95–100%), one reported moderate benefit (50%), one patient reported a temporary marked benefit (50%) for 6 months followed by recurrence of headache at the pre-ONS baseline, and one failed to respond. The onset of the benefit was rapid (within 2 weeks) with attacks recurring rapidly when the stimulator was switched off or malfunctioned. One patient developed hemicrania continua 1 month after implantation and was successfully treated with indometacin.

Conclusion ONS appears to offer a safe treatment option, without significant morbidity, for medically intractable SUNCT and SUNA.