Vagus Nerve Stimulation: Treatment for Gulf Veterans With Gulf War Illness

Inclusion Criteria: To be eligible for enrollment in the Study, patients must meet all of the following criteria: * Patient is a veteran of the 1990-91 Gulf War, aged at least 42 years old * Patient fulfills Kansas criteria for Gulf War Illness including endorsement of musculoskeletal pain at moderate or severe intensities. This means patient has endorsed symptoms in at least 3 of the following problem areas: Fatigue/sleep; musculoskeletal pain; cognitive and mood; Gastrointestinal; respiratory; skin. * Patient has widespread pain as evidenced by endorsement of pain in at least 3 bodily quadrants plus in the axial skeleton * Patient has a median 24 hour widespread pain score of at least 5 on a 0 to 10 visual analog scale (VAS) with data taken on five days * To be considered as having migraine, the patient must fulfill International Headache Society (IHS) criteria, and it should have been present for at least one year prior to entry into the study * Patient agrees to use the study device as intended, follow all of the requirements of the study including completion of diary after each self-treatment, follow-up visit requirements, complete self assessment questionnaires as scheduled, and report any adverse device effects to the study center within 24 hours of such adverse device effect. * Patient is able to provide written Informed Consent. Exclusion Criteria: Patients with any of the following will not be eligible for enrollment: * Patient has a history of intracranial aneurysm, intracranial hemorrhage, brain tumor or significant head trauma. * Patient has in the opinion of the investigator a clinically relevant structural abnormality at the gammaCore-R treatment site (e.g., neoplasm, lymphadenopathy, previous surgery, neoplasm or abnormal anatomy). * Patient has pain at the gammaCore treatment site (eg, dysesthesia, neuralgia, cervicalgia). * Patient has other significant pain problem (e.g., cancer pain or other head or facial pain disorder) that in the opinion of the investigator may confound the study assessments. * Patient has known or suspected severe cardiac disease (e.g., symptomatic coronary artery disease, prior myocardial infarction, congestive heart failure (CHF), significant premature ventricular contraction) or a history of cardiac arrhythmia. * Patient has known or suspected cerebrovascular disease (e.g., prior stroke or transient ischemic attack, symptomatic carotid artery disease, prior carotid endarterectomy or other vascular neck surgery). * Patient's electrocardiogram shows evidence of heart disease or arrhythmia including an abnormal baseline ECG (e.g. second and third degree heart block, prolonged QT interval (corrected QT (QTcB) interval \>470 msec for women and \> 450 for men), atrial fibrillation, atrial flutter, history of ventricular tachycardia or ventricular fibrillation, or clinically significant premature ventricular contraction) or a history of cardiac arrhythmia. * Patient has had a previous cervical vagotomy. * Patient has uncontrolled high blood pressure (systolic bp \>160, or diastolic bp \> 100) after 3 measurements within 24 hours. * Patient is currently implanted with an electrical and/or neurostimulator device (e.g. cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant, Sphenopalatine ganglion stimulator or Occipital nerve stimulator). * Patient has been implanted with metal cervical spine hardware or has a metallic implant near the gammaCore-R stimulation site. * Patient has a history of significant syncope within the last 5 years. * Patient has a history of non-epileptic or epileptic seizures within the last 5 years. * Patient, in the opinion of the investigator, has a known history or suspicion of substance abuse or addiction within the last 5 years. * Patient, in the opinion of the investigator/research staff, the patient is incapable of operating the gammaCore-R device as intended and performing the data collection procedures. * Patient has a psychiatric or cognitive disorder and/or behavioral problem which in the opinion of the clinician may interfere with the study (e.g. Bipolar Disorder, depressive disorder with psychotic features, Specific Phobia, Acute Stress Disorder). * Patient is pregnant or thinking of becoming pregnant in the next 6 months, or is of childbearing years and unwilling to use an accepted form of birth control or is unwilling to undergo pregnancy testing. * Patient is nursing * Patient has undergone botulinum toxin (BOTOX) injections of the head and/or neck in the last 3 months. * Patient is participating or has participated in any other therapeutic clinical investigation during the last 30 days. * Patient belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with follow-up requirements, or provide self-assessments is compromised (e.g., homeless, developmentally disabled, prisoner). * Patient has evidence of suicidality based on the Columbia Suicide Screening test * Patient has previously used a gammaCore device. * Patient is the spouse or housemate of someone else in the trial.