The efficacy of intranasal kinetic oscillation stimulation using the Chordate System S211 as a preventative treatment will be examined in patients diagnosed with chronic migraine. The medical device system will be applied in 6 treatments at weekly intervals. The study will examine the effects on monthly headache days with moderate to severe intensity.

This is a randomized, placebo-controlled, double-blind, multicenter clinical investigation of a medical device. The study consists of a 4-week screening period, a 6-week treatment period (2 weeks run-in and a 4-week observation window to assess the treatment effect), and a 4-week follow-up period.

The study primarily aims at evaluating the effect of intranasal kinetic oscillation stimulation using the Chordate System S211 as a preventative treatment on monthly headache days with moderate to severe intensity.

Inclusion Criteria:

1. The subject is legally competent, has been informed of the nature, the scope and the relevance of the study, voluntarily agrees to participation and the study's provisions, and has duly signed the informed consent form (ICF);
2. Male or female aged between 18 and 65 years (inclusive) at the time of providing informed consent;
3. Diagnosed as suffering from chronic migraine with or without aura (≥15 headache days per month for more than 3 months before screening including at least 8 migraine days) according to the IHS classification (International Classification of Headache Disorders [ICHD]-III beta);
4. Migraine onset before the age of 60 years;
5. Reported history of migraine for at least 1 year before screening;
6. Reported stable prophylactic migraine medication regimen, if any, during the 3 months prior to screening;
7. Able and willing to maintain current prophylactic migraine medication regimen (no change in type, frequency or dose) from screening to end of follow-up;
8. Women of childbearing potential must be willing to use highly effective contraceptive methods (failure rate <1% per year when used consistently and correctly) during the study.

Exclusion Criteria:

1. Unable to distinguish between migraine headaches and other headache types;
2. Treatment with Botox in the head/neck area within 4 months of the screening visit, or planned Botox treatment during the study;
3. Previous or ongoing treatment with an implanted stimulator or other implanted device in the head and/or neck;
4. Known pronounced anterior septal deviation, or other known relevant abnormality in the nasal cavity, including bacterial infection and wounds;
5. History of relevant sinus surgery, transsphenoidal surgery for pituitary or other lesions or cerebrospinal fluid (CSF) rhinorrhea;
6. Fitted with a pacemaker/defibrillator;
7. Previously treated with therapeutic x-ray intervention in the facial region (that could have influenced the nasal mucosa);
8. Ongoing upper respiratory infection or malignancy in the nasal cavity;
9. History of regular nose bleeding (epistaxis), or concomitant condition or medication that could cause excessive bleeding including treatment with an anticoagulant;
10. Head injury or open wound that contraindicates use of the Chordate Headband;
11. Known allergy to polyvinylchloride, a material used in the Chordate Catheter, or medicinal liquid paraffin;
12. Concurrent condition or risk of non-compliance that, in the investigator's opinion, may affect the interpretation of performance or safety data or which otherwise contraindicates participation in a clinical investigation;
13. Pregnant and lactating women;
14. Participation in a clinical investigation within 3 months of enrolment or planned participation at any time during this clinical investigation;
15. Previous participation in this study;
16. Employees of the study site or the sponsor directly involved with the conduct of the study, or immediate family members of any such individuals.

Due to uncertainties in EU data protection legislation individual deidentified participant data are not shared. The main uncertainty is the concept of what "deidentified" means. It appears not to mean that the data set of a person is simply separated from the person's name. What additional operations have to be done appears to depend on technological capabilities to re-identify the persons associated with the data set. A common perception is that the technological capabilities for re-identification are permanently increasing. This could have the effect that public data sets that are regarded as deidentified now might become re-identifiable data sets in the future. Once this happens, the sponsor is no longer able to make the publication of the data sets un-happen. This could result in punishment by EU data protection authorities. The sponsor wants to avoid this.