A Monocentric, Single-arm, Single-blind Withdrawal First-in-human Study to Assess the Initial Safety, Tolerability, and Effectiveness of the ONSS Bilateral Occipital Nerve Field Stimulation System for the Prophylactic Treatment of Chronic Cluster Headache in Difficult-to-treat Subjects.
The purpose of this clinical trial is to evaluate the safety and effectiveness of the Occipital Nerve Stimulation System (ONSS) in treating chronic cluster headache in adults. The study aims to answer the following questions: * What adverse events or medical complications occur following ONSS implantation and stimulation? * Does treatment with the ONSS reduce the frequency of cluster headache attacks compared with baseline? Participant Involvement Participants will: * Undergo implantation of the ONSS device. * Use the ONSS for a 48-week treatment period. * Attend scheduled clinic visits for follow-up assessments and device evaluations. * Maintain a diary documenting cluster headache attacks and use of rescue medications. * Complete study-related assessments throughout the study period.
• ICHD-3 criteria for chronic cluster headache
• Documented history of CCH since at least 1 year
• Minimum mean attack frequency of 4 attacks per week at baseline (-4week to +2 week up to implant)
• Documented minimum 4 weeks of retrospective cluster headache diary data
• Age range: 22-70 years
• Difficult-to-treat CCH with documented previous complete failure, insufficient efficacy, intolerance, or contra-indications to most preventive CH treatments among which are oral steroids or suboccipital infiltrations, verapamil, lithium carbonate and topiramate.
• No preventive CH treatment or stable preventive CH medication for ≥ 2 weeks before enrolment.
• Subject agrees not to change existing treatment during the whole duration of the trial.
• Participant written informed consent provided before enrolment
• Participant willing and capable of subjective evaluation and to fill in an electronic CH diary, to understand questionnaires, and to read, understand and sign the written informed consent form.
⁃ Partcipant willing and able to comply with study-related requirements, procedures, and visits.