Biomagnetic Characterization of Gastric Dysrhythmias III

There is a tremendous clinical need for a noninvasive technique that can assess gastric electrical activity and would be repeatable without any exposure to radiation. Investigators developed a new technique allowing to use noninvasive methods to assess bioelectrical activity in the gastrointestinal system. This has enabled to characterize the normal and pathologic physiology of the stomach through the use of noninvasive magnetogastrogram (MGG) records. Primary hypothesis for this proposal is that analysis of gastric slow wave uncoupling and propagation in multichannel MGG discriminates between normal and pathological gastric electrical activity. Eventually, investigators envision this research leading to new insights for gastrointestinal conditions such as gastroparesis, functional dyspepsia and chronic idiopathic nausea that would inform clinical management of these debilitating diseases.

Studies have demonstrated that the magnetogastrogram (MGG) records the same gastric slow wave activity that detect with serosal and mucosal electrodes. The upgraded magnetometer will improve the spatial resolution resulting in increased sensitivity for detecting and characterizing both abnormal frequency dynamics and abnormal spatiotemporal patterns. The spatiotemporal data collected with multichannel Superconducting QUantum Interference Device (SQUID) biomagnetometer has allowed , for the first time, to characterize propagation of the gastric slow wave noninvasively. In addition to frequency dynamic changes, which are the only reliable parameters from cutaneous electrogastrogram (EGG), and which still do not necessarily correlate well with disease, the MGG reflects normal and abnormal gastric slow wave activity. Furthermore, for the first time, investigators have demonstrated that propagation characteristics determined magnetically distinguish normal subjects from patients with gastroparesis. Also for the first time, investigators have been able to detect the gradient in gastric propagation velocity noninvasively in animal subjects. However, investigators still have unresolved questions about how MGG propagation rhythm and pattern disturbances may specify functional disorders.

Diabetics Without Symptoms of Gastroparesis, Diabetic Gastroparesis, Idiopathic Gastroparesis, Total or Partial Gastrectomy, Chronic Nausea, Functional Dyspepsia

Noninvasive measurement of gastric slow wave dysrhythmia in pediatric patients with nausea and functional dyspepsia

Inclusion Criteria: Participants between ages 12-80 Diabetic patients with gastroparesis, diabetic patients without gastroparesis and who are willing to have a gastric emptying test if they have not had one in the last 6 months and an IV inserted. Patients with idiopathic gastroparesis Total or partial gastrectomy patients Children (ages 12-17) with functional dyspepsia Children (ages 12-17) with chronic nausea Exclusion Criteria: Those with claustrophobia who cannot lie still under the SQUID for the length of time required. Normal participants with known intestinal complications Pregnant females (females who are able to have children will be given a pregnancy test). Morbid obesity (these patients are presumably unable to lie under the current generation of SQUID devices). Patients with a history of cardiac arrhythmias, taking anticoagulants, or greater than 80 years of age will be excluded.

Bradshaw LA, Cheng LK, Chung E, Obioha CB, Erickson JC, Gorman BL, Somarajan S, Richards WO. Diabetic gastroparesis alters the biomagnetic signature of the gastric slow wave. Neurogastroenterol Motil. 2016 Jun;28(6):837-48. doi: 10.1111/nmo.12780. Epub 2016 Feb 3.

Bradshaw LA, Kim JH, Somarajan S, Richards WO, Cheng LK. Characterization of Electrophysiological Propagation by Multichannel Sensors. IEEE Trans Biomed Eng. 2016 Aug;63(8):1751-9. doi: 10.1109/TBME.2015.2502065. Epub 2015 Nov 19.

Kim JH, Pullan AJ, Bradshaw LA, Cheng LK. Influence of body parameters on gastric bioelectric and biomagnetic fields in a realistic volume conductor. Physiol Meas. 2012 Apr;33(4):545-56. doi: 10.1088/0967-3334/33/4/545. Epub 2012 Mar 14.

Somarajan S, Cassilly S, Obioha C, Richards WO, Bradshaw LA. Effects of body mass index on gastric slow wave: a magnetogastrographic study. Physiol Meas. 2014 Feb;35(2):205-15. doi: 10.1088/0967-3334/35/2/205. Epub 2014 Jan 7.

Somarajan S, Muszynski ND, Obioha C, Richards WO, Bradshaw LA. Biomagnetic and bioelectric detection of gastric slow wave activity in normal human subjects--a correlation study. Physiol Meas. 2012 Jul;33(7):1171-9. doi: 10.1088/0967-3334/33/7/1171. Epub 2012 Jun 27.