BlueCross BlueShield of Tennessee Medical Policy Manual

Cutaneous Electrogastrography (EGG)


Electrogastrography (EGG) describes the recording and interpretation of electrical activity of the stomach, typically from the skin surface.  The electrical activity of the stomach can be subdivided into two general categories: electrical control activity (ECA) and electrical response activity (ERA). ECA is characterized by regularly recurring electrical potentials, originating in the gastric pacemaker located in the corpus of the stomach and sweeping in an annular band with increasing velocity toward the pylorus. ECA is not associated with contractions of the stomach unless coupled with action potentials, referred to as ERA.

The usual practice is to record several cutaneous EGG signals from various standardized positions on the outside of the abdominal wall and to select the one with the highest amplitude for further analysis. Nonetheless, the recorded signal is relatively weak and difficult to distinguish from the surrounding background "noise" related to unwanted signals, such as cardiac, respiratory, duodenal, and colonic electrical activity. The EGG is usually evaluated in terms of changes in the EGG amplitude and frequency. Deviations from the normal frequency of 3 cycles per minute may be referred to as brady- or tachygastria.

The use of EGG has been most widely studied in individuals with gastroparesis and functional dyspepsia. Scintigraphic gastric emptying is the typical test for evaluating gastroparesis. Scintigraphic gastric emptying involves the ingestion of a solid meal with 99-technetium added. Serial measurements are then done every 20 minutes for 2-3 hours. Delayed gastric emptying is diagnosed if more than 50% of the radio-labeled food is retained at the end of the study period.




The published literature suggests that EGG is primarily used as a research tool in individuals with a variety of disorders. Other studies continue to focus on the technical performance of the test, including the use of multichannel recording compared to single channel recording.  There is a lack of high quality studies that compare EGG with conventional diagnostic tools.  Data are currently inadequate to determine how the results of EGG may improve health outcomes.


American Gastroenterological Association. (2004). Medical Position Statement: Diagnosis and Treatment of Gastroparesis. Retrieved June 1, 2010 from

American Neurogastroenterology, American Motility Society & Society of Nuclear Medicine. (2008). Consensus recommendations for gastric emptying scintigraphy: a joint report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine. Retrieved July 29, 2016 from

National Institute of Diabetes and Digestive and Kidney Diseases. (2016). Gastroparesis. Retrieved July 27, 2016 from

O’Grady, G., & Abell, T. (2015). Gastric arrhythmias in gastroparesis: low and high resolution mapping of gastric electrical activity. Gastroenterology Clinics of North America, 44 (1), 169–184. (Level 5 evidence)

Palmetto Government Benefits Administrators. (2019, January). Local Coverage Determination (LCD): Noncovered Services other than CPT® Category III Noncovered Services (L36954) Retrieved April 29, 2019 from




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