Dr. Arun Aggarwal Gastroenterologist explains the Electrogastrogram (EGG) Which is the graphic Producer of stomach

1. Electrogastrogram Jayson Franky Dana By: Dr Arun Aggarwal Gastroenterologist

2. Discovery • William Beaumont– 1833 • First to notice gastric psychological changes induced by various emotions. • Later noted emotion causes increased and decreased gastric acid formation • Also causes reflux of bile into stomach causing the slowing of gastric emptying By: Dr Arun Aggarwal Gastroenterologist

3. October 14, 1921 • First recording of Electrogastrogram • Scientists begin to discover changes due to specific stimuli such as stress and anxiety • Use EEG to measure gastric emptying • Recent research has shown that improving quality of life will improve gastrointestinal disease. By: Dr Arun Aggarwal Gastroenterologist

4. What is EGG • Like EKG and heart • Measures muscle activity related to the stomach and abdominal region. • Measured from a baseline reading containing a regular rhythm. In a normal subject a current increase is observed after a meal. • Still an early experimental procedure because it has yet to become a standard medical procedure. By: Dr Arun Aggarwal Gastroenterologist

5. Gastrointestinal Problems • Nausea • Gastric Reflux • Peptic Ulcer • Irritable Bowel Syndrome • Cirrhosis By: Dr Arun Aggarwal Gastroenterologist

6. Nausea • Uneasy feeling; feeling of vomiting • Commonly associated with stomach but including all parts of the body • Brought on by any and all physiological stimuli • May cause dehydration or esophageal erosion and irritation By: Dr Arun Aggarwal Gastroenterologist

7. Gastric Reflux • Very common • Reflux of stomach content into esophagus • Causes damage to lining if occurring often • Heartburn, burning pain • Treatable with weight reduction, avoiding food and activities that cause reflux, avoiding situations that cause reflux, and some medication. By: Dr Arun Aggarwal Gastroenterologist

8. Peptic Ulcers • Break in surface of organ • Excessive HCl formation, infection, some drugs (asprin, anti inflammatory) • Indigestion, nausea, vomiting, bleeding • Monitor pH levels in stomach • Use biofeedback to maintain appropriate HCl amounts By: Dr Arun Aggarwal Gastroenterologist

9. Irritable Bowel Syndrome • Most common psychophysiological disease • Caused by stress and anxiety and effects all parts of the digestive tract • Stress increases corticotropin-releasing factors from brain inhibiting gastric emptying By: Dr Arun Aggarwal Gastroenterologist

10. IBS (Cont) • Causes various symptoms: abdominal pain, altered bowel habit, bloating, bowel noises, indigestion, nausea, headaches, etc. • Avoid problematic food, improve bowel function, antidepressant medication, relaxation therapy, psychological counseling By: Dr Arun Aggarwal Gastroenterologist

11. Cirrhosis • Extended liver damage • Not directly caused by emotional stimuli • Alcohol abuse, drug abuse (hepatitis), AIDs • Generally found amoung older individuals • Irreversible By: Dr Arun Aggarwal Gastroenterologist

12. References • Mai FM. 1988. Beaumont’s Contribution to gastric psychophysiology: a reappraisal. Can J Psychiatry. 33: 650-653. • Muth ER, Koch KL, Stern RM, Thayer JF. 1999. Effect of autonomic nervious system manipulations on gastric myoelectrical activity and emotional responses in healthy human subjects. Psychosom Med. 61: 297-303. • www.gastro.net.au/gastrodiseases/index.php3 By: Dr Arun Aggarwal Gastroenterologist

13. Electrogastrography (EGG) By: Dr Arun Aggarwal Gastroenterologist

14. Electrogastrography • How it works. • Difficulties. • Precautions. • EGG setup. • Data acquisition and analysis. • Capabilities and limitations of EGG. • Applications. By: Dr Arun Aggarwal Gastroenterologist

15. How EGG Works • Very similar to EKG. • Recording of electrical signals produced by the muscles of the stomach that control constriction. • Two forms. By: Dr Arun Aggarwal Gastroenterologist

16. Difficulties • The main difficulty is the human EGG signal. • 3 cycles/min sinusoid. • Data obtained is difficult to analyze and abnormalities difficult to define. • Interference from the duodenum and from the transverse and descending colon. By: Dr Arun Aggarwal Gastroenterologist

17. Precautions • Optimal recording conditions. • Electrodes produce noise to an extent. • Noise must be reduced (0-0.5Hz). • Electrodes should be recessed. • Skin abrasion. • Ideally impedance below 10 Kila-ohmes. By: Dr Arun Aggarwal Gastroenterologist

18. EGG setup • EGG signal is recorded by electrodes that are placed over the upper abdomen. By: Dr Arun Aggarwal Gastroenterologist

19. EGG setup • EGG sample amplitude is typically in the 50-100 micro-Volt range. • Must be filtered. • Removes artifacts. • Provides a low and high frequency cutoff (1cpm and 18cpm) By: Dr Arun Aggarwal Gastroenterologist

20. Data acquisition and analysis • Bradygastrias • O-2.4cpm • Tachygastrias • 3.6-9.9cpm • These Gastric Dysrhythmias have clinical relevance. By: Dr Arun Aggarwal Gastroenterologist

21. Capabilities and Limitations (Frequency) • Most reliable EGG parameter. • Stable frequencies obtained over a population. • Low standard deviation between measurements. • Slight increase in gastric frequency obtained after feeding (only in some people). By: Dr Arun Aggarwal Gastroenterologist

22. Capabilities and Limitations (Amplitude) • With decrease between electrode distance mean power of the major EGG component decays. • Bipolar channels yield stronger signals but are more sensitive to movement artifacts. • Results over a population were surprisingly varied after having eaten. • Poor correlation between amplitude of the EGG signal and the presence of gastric contractions. • In dogs data was recorded for contractions that had been blocked by atropine and glucagon. By: Dr Arun Aggarwal Gastroenterologist

23. Capabilities and Limitations (Time Shifts) • Shifts during periods of greatest stability of EGG channel pairs near non existent regardless of relative difference. • However simultaneous internal recordings from dogs and patients show well defined time shifts. By: Dr Arun Aggarwal Gastroenterologist

24. Capabilities and Limitations (Waveform) • Increased inter electrode distance in internal bipolar recordings results in a change of waveform. (biphasic to sinusoidal) • Occasional changes in waveform will be found in any participant including those deemed normal. By: Dr Arun Aggarwal Gastroenterologist

25. Capabilities and Limitations (Discussion) • Frequency is most reliable parameter for clinical applications. • Electrodes. • Artifact filtering. • Amplification techniques. • Recorded deviations will be related to gastric electrical abnormalities. By: Dr Arun Aggarwal Gastroenterologist

26. Applications • Motion Sickness • Gastric Emptying and Motility • Nausea and Vomiting • Gastric Dysrhythmias • EGG in Children By: Dr Arun Aggarwal Gastroenterologist

27. References • Chen, J. A. McCallum, R. W. (1994). Electrogastrography Principles and Applications. Raven Press., New York. By: Dr Arun Aggarwal Gastroenterologist

28. Current Research in Gastric Psychophysiology By: Dr Arun Aggarwal Gastroenterologist

29. A lot of research has been done to investigate the effects of the mind, mood, and voluntary behaviors on the digestive system • Gastric psychophysiology refers to the stomach or anything relating to it By: Dr Arun Aggarwal Gastroenterologist

30. Psychophysiology of Nausea (A study conducted by R.M. Stern in 2002) Investigation Topic: nausea (uncomfortable sensation usually associated with the stomach and occasionally followed by vomiting) Nausea (like emotional pain or motion sickness) is a private sensation, so little is known. Hypothesis: each individual has a personal threshold for nausea dependant on interaction of inherent factors and changeable physiological factors. By: Dr Arun Aggarwal Gastroenterologist

31. Results and Conclusions of Nausea Study Results: subjects observed showed an increase in sympathetic nerve activity, decrease in parasympathetic nerve activity, increase in abnormal dysrhythmic gastric activity, increase in plasma vasopressin Conclusions: beneficial selective reduction of nausea depends on a greater knowledge of its psychophysiological variables. By: Dr Arun Aggarwal Gastroenterologist

32. Psycho-Physiological Aspects of Gastroesophageal Reflux Disease (a review study by Kamolz, Bammer, Pasuit, Pointner in 2002) Investigation Topic: confirmed the strong relationship between psychophysiological aspects and gastrointestinal diseases… Additionally: investigated interventions into these relationships and focused in on Gastroesophageal reflux disease (GERD). By: Dr Arun Aggarwal Gastroenterologist

33. GERD study • Gastroesophageal reflux disease (more commonly known as acid reflux) occurs when the liquid contents of the stomach are regurgitated into the esophagus, thus damaging the lining of the esophageal walls • Occurs in as many as 10% of Americans per day, 44 % expressing symptoms at least once a month • can be caused/contributed to by the lower esophageal sphincter, significant stressors, hiatal hernias, esophogeal contractions, and the emptying of the gastric chamber. By: Dr Arun Aggarwal Gastroenterologist

34. GERD • Other physiological factors that may contribute to GERD: • Delayed clearance of physiological reflux by saliva • Decreased bicarbonate secretion by esophageal submucosal glands • Attenuated ability of cells lining esophagus to resist acid injury By: Dr Arun Aggarwal Gastroenterologist

35. GERD • Treatments: • Prilosec (a proton pump inhibitor) • Antacids • Lifestyle changes • Elevate head of bed 6inches, decrease fat intake, smoking cessation, weight reduction, avoiding large meals • Endoscopy • Ambulatory pH monitoring (a pH monitor is placed on the esophageal sphincter) By: Dr Arun Aggarwal Gastroenterologist

36. Psychological and Sex Features of delayed gut transit in functional gastrointestinal disorders Study by Bennett, et al. in 2000. Investigation Topic: comparing psychosocial and demographic features of patients w/ functional gastrointestinal disorders and delayed transit in the gastrointestinal tract regions 110 subjects, 46 w/ delayed transit in region 1, 32 delayed transit for region II, and 17 had normal transit By: Dr Arun Aggarwal Gastroenterologist

37. Delayed Gut Transit Study • Gut transit was assessed using a scintigraphic technique, psychometric measures were used to judge psychological status • RESULTS: delayed transit was increased in females, those with depressive mood states, increasing age, frequent control of anger, and severe gastric stasis, whereas Increased transit was found in males and hypochondriasis. CONCLUSIONS: a distinct psycho physiological subgroup defined by delayed gut transit is indicative of gastrointestinal disorders. By: Dr Arun Aggarwal Gastroenterologist

38. Effects of different psychophysiological stressors on the cutaneous electrogastrogram in healthy subjects. A study by Riezzo, Porcelli, Guerra, and Giorgio in 1996 Investigation Topic: following psychophysiological stress on gastric electrical activity Apparatus used: a non invasive, cutaneous electrogastrography (EGG) By: Dr Arun Aggarwal Gastroenterologist

39. Cutaneous EGG study • 3 stressful tests (a cold pressor test, arithmetic test, and Stroop color-word test • A non stressful tests (reading a booklet) • EGG parameters were measured: dominant frequency, coefficient variation of dominant frequency, and gastric power) and were recorded during baseline, task, and rest periods. By: Dr Arun Aggarwal Gastroenterologist

40. Cutaneous EGG study • RESULTS: • Non stressful task had no effects • During stress (especially arithmetic test) gastric power significantly increased. Stroop test showed nearly significant trend to increases in gastric power. CONCLUSIONS: increased individual susceptibility to psychological stress may influence the EGG responses and thus increase gastric electrical activity. By: Dr Arun Aggarwal Gastroenterologist

41. Antidepressants Attenuate Increased Susceptibility to Colitis in Murine Model of Depression Varghese, et al. in 2005. Based on the theory that psychiatric factors determine gastrointestinal health Investigation Topic: using a model of depression, attempted to find alterations in gut physiology and to assess association with increased sensitivity to experimental colitis in adulthood. (also investigated effects of antidepressants therapy) By: Dr Arun Aggarwal Gastroenterologist

42. Depression Study • Using mice: some mouse pups were seperated from their mother, some weren’t. At 8 weeks, pups were evaluated on behavior changes, intestinal permeability, and sensitivity to colitis. RESULTS: adult mice that had been seperated showed depressive behaviors and enhanced intestinal permeability with more severe colitis. CONCLUSIONS: maternal seperation can lead to depression/increased responsiveness to stress, impaired intestinal function, and vulnerability to gastric inflammation. By: Dr Arun Aggarwal Gastroenterologist

43. Peptic Ulcer Disease – nothing but an infection? • M. Gross & C. Herrmann in 1999. Investigated: duodenal and gastric ulcers and stressors RESULTS: 73% of patients had gastric ulcers, 92% had duodenal ulcers. Relapse was 50% and 66%, respectively after 1 year without eradication of the ulcer. After eradication, relapse rates reduced to 0% and 6%, respectively, suggesting an infectious agent……. By: Dr Arun Aggarwal Gastroenterologist

44. Peptic Ulcer • HOWEVER: only a minority had the Helicobacter pylori infection! • CONCLUDED: chronic physiological stress is an ulcerogenic co-factor, interaction between stress and infection can cause ulcers, acute psychological stressors show increased risk of gastric ulcer formation. By: Dr Arun Aggarwal Gastroenterologist

45. REFERENCES • Bennett, E., Evans, P., Scott, A., Badcock, C, Shuter, B., Hoscle, R., Tennant, C., Kellow, J. (2000). Psychological and sex features of delayed gut transit in functional gastrointestinal disorders. GUT. 46(1): 83-87. • Gross, M. & Herrmann, C. (1999). Peptic Ulcer Disease- nothing but an infection? Zeitschrift Fur Psychosomatische Medizin Und Psychotherapie. 45 (4): 390-400. • Kamolz, T, Bammer, T., Pasuit, M., & Pointner, R. (2002). Psycho-physiological aspects of gastroesophageal reflux disease. Psychotherapie Psychosomatik Medizinische Psychologie 52 (3-4): 159-165. • Riezzo, G., Porcelli, P., Guerra, V., & Giorgio, I. (1996). Effects of different psychophysiological stressors on the cutaneous electrogastrogram in healthy subjects. Archives of Physiology and Biochemistry 104(3): 282-286. • Stern, R.M. (2002). The psychophysiology of Nausea. Acta Biologica Hungarica 53(4): 589-599. • Varghese, A., Verdu, E., Bercik, P., Khan, W., Blennerhassett, P., Szectman, H., & Collins, S. (2006) Gastroenterology 130(6) 1743-1753. By: Dr Arun Aggarwal Gastroenterologist