Prevention and Acute Treatment of Chronic Cluster Headache Compared to Standard of Care

Inclusion Criteria: 1\. Signed Informed Consent Form 2. Subjects between the age of 18-70, both genders 3. Subjects diagnosed with chronic cluster headache for at least 1 year, without remission periods or with remission periods lasting \<1 month, in accordance with the ICHD-II classification criteria (2ndEd): a. At least 5 attacks fulfilling the following criteria: i. Severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15-180 minutes if untreated ii. Headache is accompanied by at least 1 of the following: 1. Ipsilateral conjunctival injection and/or lacrimation 2. Ipsilateral nasal congestion and/or rhinorrhea 3. Ipsilateral eyelid oedema 4. Ipsilateral forehead and facial sweating 5. Ipsilateral miosis and/or ptosis 6. A sense of restlessness or agitation iii. Attacks have a frequency from 1 every other day to 8 per day and are not attributed to another disorder iv. Attacks recur over \> 1 year without remission periods or with remission periods lasting \< 1 month. 4\. Has minimum mean attack frequency of 4 CH attacks per week. 5. Is able to distinguish CH from other headaches (i.e. tension-type headaches). 6\. Is capable of completing headache pain self-assessments. 7. Agrees to use the GammaCore® device as intended and follow all of the requirements of the study, including follow-up visit requirements. 8\. Is willing to keep all concomitant medication stable during the entire study period. 9\. Women of child-bearing potential must use 2 methods of contraceptive i.e. hormones and condom. Exclusion Criteria: 1. Is currently taking CH prophylactic medication for indications other than CH which in the opinion of the clinician may interfere with the study 2. Has had a change in type or dosage of prophylactic headache medications \< 1 month prior to enrollment 3. Has a history of intracranial or carotid aneurysm, intracranial hemorrhage, brain tumors or significant head trauma. 4. Has a lesion (including lymphadenopathy), dysaesthesia, previous surgery or abnormal anatomy at the GammaCore® treatment site. 5. Has other significant pain problem that might confound the study assessments in the opinion of the investigator. 6. Has known or suspected severe atherosclerotic cardiovascular disease, severe carotid artery disease (e.g. bruits or history of TIA or CVA), congestive heart failure (CHF), known severe coronary artery disease or recent myocardial infarction (within 5years). 7. Has had a previous unilateral or bilateral vagotomy. 8. Has uncontrolled high blood pressure. 9. Is currently implanted with an electrical and/or neurostimulator device, including but not limited to cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant. 10. Has a history of carotid endarterectomy or vascular neck surgery on the right side. 11. Has been implanted with metal cervical spine hardware or has a metallic implant near the GammaCore® stimulation site. 12. Has a history, the last 12 month, of syncope. 13. Has a history, the last 12 month of seizures. 14. Has a known history or suspicion of substance abuse or addiction, or overuse of acute headache medication for headaches other than CH. 15. Has psychiatric or cognitive disorder and/or behavioral problems which in the opinion of the investigator may interfere with the study 16. In the opinion of the investigator the subject is incapable of operating the GammaCore® device as intended and performing the data collection procedures. 17. Is participating in any other therapeutic clinical investigation or has participated in a clinical trial in the preceding 30 days. 18. Woman who are pregnant or lactating.