Occipital nerve stimulation with the bion® microstimulator for the treatment of medically refractory chronic cluster headache

Background: chronic cluster headache is a severely disabling neurological disorder. evidence from open-label case series suggest that occipital nerve stimulation may be effective for the treatment of chronic cluster headache. objective: to evaluate the effectiveness of a microstimulator for chronic cluster headache. study design: prospective,observational feasibility study plus medical record review. settings: academic medical center. methods: four patients with medically refractory chronic cluster headache underwent implantation of a unilateral bion microstimulator. in-person follow-up was conducted for 12 months after implantation,and a prospective follow-up chart review was carried out to assess long term outcome. results: three of the participants returned their headache diaries for evaluation. the mean duration of chronic cluster headache was 14.3 years (range 3 to 29 years). pain was predominantly or exclusively retroocular/periocular. one participant demonstrated a positive response (> 50% reduction in cluster headache frequency) at 3 months postimplant,while there were 2 responders at 6 months. at least one of the participants continued to show > 60% reduction in headache frequency at 12 months. a chart review showed that at 58-67 months post-implant,all 3 participants reported continued use and benefit from stimulation. no side-shift in attacks was noted in any participant. adverse events were limited to 2 participants with neck pain and/or cramping with stimulation at high amplitudes; one required revision for a faulty battery. limitations: small patient population without control group. not blinded or randomized. conclusion: unilateral occipital nerve stimulation,using a minimally invasive microstimulator,may be effective for the treatment of medically refractory chronic cluster headache. this benefit may occur immediately after implantation,remain sustained up to 5 years after implantation,and occur despite the anterior location of the pain. prospective,randomized controlled trials of occipital nerve stimulation in chronic cluster headache should proceed.