Non-invasive Markers of Esophageal Function in Adults

Dysphagia, or difficulty with swallowing, is a common symptom affecting nearly 9.4 million individuals or 4% of the US population. High resolution esophageal manometry is currently considered the gold standard test for evaluation and diagnosis of esophageal motility disorders, but given that it requires trans-nasal placement in a conscious patient, this test is highly uncomfortable and associated with significant patient dissatisfaction. There are currently no noninvasive tests or markers available to test esophageal function and motility.

In the upper gastrointestinal system, as in the heart, disruption of the electrical syncytium in disease produces measurable dysrhythmia. Recent modifications of the standard electrogastrogram (EGG) that have increased the number of leads to 25 (termed high-resolution EGG) have allowed enhanced spatio-temporal resolution of electric slow wave activity, and newer analytic techniques. Additionally, the magnetogastrogram (MGG) overcomes many of the inherent limitations of the standard EGG. The goal of this proposal is to harness similar technologies applied to the esophagus to develop high-resolution electroesophagogram (EESG) and magnetoesophagogram (MESG) as noninvasive clinical methods to quantify esophageal function and motility disorders, which could guide intervention for a large number of adult patients.

The main aims in this proposal are to develop a mathematical model of esophageal function and characterize phenotypes of esophageal motility disorders using EESG/MESG in healthy controls and esophageal dysmotility patients and determine how EESG/MESG rhythm and pattern abnormalities relate to physiologic function.

Inclusion criteria

• Adults ≥ 18 years of age who are undergoing HRM for routine standard of care evaluation for esophageal motility.
• Normal control participants (ages ≥ 18 years) who have no known gastrointestinal complications.

Exclusion criteria

• Those with claustrophobia who cannot lie still under the SQUID for the length of time required
• Due to interference with signal acquisition, subjects with contraindication to undergoing an MRI scan as noted in the MRI Safety checklist by Vanderbilt University Medical Center (such as with heart pacemakers, metal implants, or metal chips or clips) will not undergo SQUID, but can still be eligible to do cutaneous EESG.
• Morbid obesity (these patients are potentially unable to lie under the current generation of SQUID devices)
• Patients with a history of cardiac arrhythmias or taking anticoagulants will be excluded