Non-invasive Vagal Nerve Stimulation (nVNS) for Symptomatic Exacerbation of Nausea in Patients With Gastroparesis and Related Disorders

Inclusion Criteria:

• Age 18 years or older at registration.

• Diagnosis of gastroparesis as documented by gastric emptying scintigraphy (4-houremptying after a low-fat meal with any combination of 2- and 4-hour retention of >60% and 10%, respectively), or Chronic Unexplained Nausea and Vomiting (CUNV).

• Ongoing symptoms (i.e. Nausea and vomiting, bloating, and abdominal pain) with anausea score of 3 or more on the patient assessment of upper gastrointestinaldisorders-symptom severity index (PAGI-SYM) scale at baseline (moderate to severenausea).

• Exclusion of other causes of symptoms such as mechanical gastrointestinalobstruction, uncontrolled esophagitis, peptic ulcer disease, etc. By standardradiographic or endoscopic tests.

• Use of the following medications on an as-needed basis: ondansetron, promethazine orprochlorperazine but no more than four times a day.

Exclusion Criteria:

• Another active disorder, which could explain symptoms in the opinion of theinvestigator.

• Age < than 18 years.

• Pregnancy or nursing.

• A previous surgery of the upper gastrointestinal tract, including vagotomy.

• Use of narcotics more than 3 days per week.

• History of prolonged QT interval or a history of clinically significant arrhythmia.

• Abnormal baseline ECG (e.g. Second- and third-degree heart block, atrialfibrillation, atrial flutter, recent history of ventricular tachycardia orventricular fibrillation, or clinically significant premature ventricularcontraction).

• Previous bilateral or right cervical vagotomy.

• Uncontrolled high blood pressure.

• Currently implanted with an electrical and/or neurostimulator device, including butnot limited to cardiac pacemaker or defibrillator, vagal neurostimulator, deep brainstimulator, spinal stimulator, bone growth stimulator, or cochlear implant.

• History of carotid endarterectomy or vascular neck surgery on the right side.

• Implanted with metal cervical spine hardware or has a metallic implant near thegammaCore stimulation site.

• Any other condition, which in the opinion of the investigator would impedecompliance or hinder the completion of the study.

• Failure to give informed consent.