Changes In Gastric Myoelectrical Activity Research Articles

TRANSCUTANEOUS MULTICHANNEL ELECTROGASTROGRAPHY: NORMAL PARAMETERS IN A BRAZILIAN POPULATION.

Electrogastrography (EGG) is a noninvasive technique for the assessment of gastric myoelectrical activity using electrodes placed on the abdominal surface. Changes in gastric myoelectrical activity may be associated with diseases such as gastroparesis, functional dyspepsia, nausea, and recurrent vomiting. In Brazil, no studies to date have assessed gastric myoelectrical activity using multichannel EGG in healthy individuals. To establish normal values of transcutaneous multichannel EGG in healthy Brazilian individuals. This was a prospective study including 20 healthy individuals who underwent EGG. Recording was performed during two periods: a preprandial recording was performed for 30 minutes, and a postprandial recording was performed for 30 minutes after a soft-solid meal of 400 kcal (20 grams of proteins, 60 grams of carbohydrates, and 9 grams of fat). We assessed dominant frequency (DF) parameters, %DF distribution, the instability coefficient, and the power ratio (PR). A total of 20 individuals (11 women and 9 men) with a mean age of 39.5±7.4 years were included. Mean DF (95%CI) ranged from 2.4 to 3.1 cpm in the resting phase and 2.6 to 3.2 cpm in the postprandial period. The %DF in normogastria range was >70% in all healthy individuals. We identified that only one individual did not present a positive response to the test meal, and the other 19 individuals showed a PR greater than 1. The instability coefficient did not change significantly with meal intake. Multichannel EGG may be applied in future studies to evaluate gastric motility disorders in the Brazilian population.

Satiety testing in diabetic gastroparesis: Effects of insulin pump therapy with continuous glucose monitoring on upper gastrointestinal symptoms and gastric myoelectrical activity.

Symptoms induced by caloric or non-caloric satiety test meals and gastric myoelectrical activity (GMA) have not been studied in patients with diabetic gastroparesis (DGP) before and after intense glucose management. Wedetermined the effects of continuous subcutaneous insulin infusion (CSII) with continuous glucose monitoring (CGM) on GI symptoms, volume consumed, and GMA induced by the caloric meal satiety test (CMST) and water load satiety test (WLST) in DGP. Forty-five patients with DGP underwent CMST and WLST at baseline and 24weeks after CSII with CGM. Subjects ingested the test meals until they were completely full. Visual analog scales were used to quantify pre- and postmeal symptoms, and GMA was recorded with cutaneous electrodes and analyzed visually and by computer. KEYRESULTS: At baseline and 24-week visits, nausea, bloating, abdominal discomfort, and fullness were immediately increased after CMST and WLST (Ps<0.01). The meal volumes ingested were significantly less than normal controls at both visits in almost one-third of the subjects. After the CMST, the percentage 3 cycle per minute GMA increased and bradygastria decreased compared with WLST (Ps<0.05). After treatment for 24weeks meal volumes ingested, postmeal symptoms and GMA were no different than baseline. CONCLUSIONS AND INFERENCES: (a) Satiety test meals elicited symptoms of nausea, bloating, and abdominal discomfort; (b) CMST stimulated more symptoms and changes in GMA than WLST; and (c) CSII with CGM for 24weeks did not improve symptoms, volumes ingested, or GMA elicited by the two satiety test meals in these patients with diabetic GP.Satiety tests in diabetic gastropresis are useful to study acutepostprandial symptoms and GMA, but these measures were not improved byintensive insulin therapy.

Gastric myoelectrical and neurohormonal changes associated with nausea during tilt-induced syncope.

Nausea is a common prodromal symptom of neurally mediated syncope, but the biological factors linking nausea with syncope have not been studied. We aimed to characterize nausea during tilt-induced syncope by exploring related changes in gastric myoelectrical activity and plasma epinephrine, norepinephrine, and vasopressin concentrations across study phases of recumbency, tilt, syncope, and recovery. Electrogastrographic and plasma hormone changes were compared between patients with tilt-induced syncope and nausea (n=18) and control subjects (n=6) without symptoms or hemodynamic changes during tilt-table testing. Over a 4-minute period preceding syncope, sequential electrogastrography epochs demonstrated an increase over time in bradygastria (P=.003) and tachygastria (P=.014) power ratios, while the dominant frequency (P<.001) and the percent normogastria (P=.004) decreased. Syncope led to significant differences between cases and controls in electrogastrographic power ratios in each frequency range: bradygastria (P=.001), tachygastria (P=.005), and normogastria (P=.03). Nausea always followed electrogastrographic changes, and nausea resolution always preceded electrogastrographic normalization. Plasma vasopressin (676.5±122.8 vs 91.2±15.3pg/mL, P=.012) and epinephrine (434±91.3 vs 48.7±2.5pg/mL, P=.03), but not norepinephrine (P>.05), also differed with syncope between cases and controls. The nausea related to tilt-induced syncope is temporally associated with changes in gastric myoelectrical activity and increases in plasma vasopressin and epinephrine. The biological mechanisms that induce syncope are physiologically distinct from other experimental models of nausea such as illusory self-motion, yet nausea with syncope appears to have similarly associated electrogastrographic and hormone changes. Thus, tilt-induced syncope could serve as an informative experimental model for nausea research.

Changes in Gastric Myoelectrical Activity in Response to Selected Cranial Osteopathic Manipulations in Healthy Young Individuals

Osteopathic manipulations in the cranial field (cranial manipulation, CM) are a part of osteopathic manipulative treatment and are commonly used to treat patients. It is suggested that CM affects the autonomic nervous system. We hypothesized that CM may have an effect on the digestive system and have conducted this study to measure gastric electrical activity in response to selected CM using non‐invasive cutaneous electrogastrography (EGG). Healthy 25–35 year old men and women participated in this study. All CM were performed by one osteopathic physician and data were recorded and analyzed using BIOPAC Systems, Inc. equipment and software. CM effectiveness was evaluated based on the changes in the amplitude of the EGG in the frequency range that is associated with gastric slow waves.Our preliminary results indicate that CM appears to decrease the amplitude of the EGG. These data suggest that selected cranial manipulations may affect gastric motility.Support or Funding InformationThis project was funded by the TUN Research Grant Award.

P4‐369: Changes in gastric myoelectrical activity in response to nicotine in a mouse model of Alzheimer's disease

P4‐369: Changes in gastric myoelectrical activity in response to nicotine in a mouse model of Alzheimer's disease

The influence of autonomic interventions on the sleep-wake-related changes in gastric myoelectrical activity in rats

Significant changes in autonomic activity occur at sleep-wake transitions and constitute an ideal setting for investigating the modulatory role of the autonomic nervous system on gastric myoelectrical activity (GMA). Using continuous power spectral analysis of electroencephalogram, electromyogram, and electrogastromyogram (EGMG) data from freely moving rats that had undergone chemical sympathetomy and/or truncal vagotomy, sleep-wake-related fluctuations in GMA were compared among the intervention groups. The pattern and extent of fluctuations in EGMG power across the sleep-wake states was blunted most significantly in rats undergoing both chemical sympathectomy and truncal vagotomy. The effect of these interventions also varied with respect to the transition between different sleep-wake states. The most prominent influences were observed between active waking and quiet sleep and between paradoxical sleep and quiet sleep. The sleep-wake-related fluctuations in EGMG power are a result of joint contributions from both sympathetic and vagal innervation. Vagotomy mainly resulted in a reduction in EGMG power, while the role of sympathetic innervation was unveiled by vagotomy and this was reflected most obviously in the extent of the fluctuations in EGMG power.

Banha-sasim-tang as an herbal formula for the treatment of functional dyspepsia: a randomized, double-blind, placebo-controlled, two-center trial

BackgroundFunctional dyspepsia (FD) is characterized by a high prevalence rate and no standard conventional treatments. Alternative therapies, such as herbal formulas, are widely used to treat FD. However, there are inadequate evidences regarding the safety and efficacy of these formulas. Moreover, the mechanisms by which herbal formulas act in the gastrointestinal tract are controversial. In traditional Korean medicine, Banha-sasim-tang has long been one of the most frequently prescribed herbal formulas for treating dyspepsia. The current study is designed to evaluate the efficacy and safety of Banha-sasim-tang for FD patients and to examine whether there will be a significant correlation between cutaneous electrogastrography recordings and dyspeptic symptoms in FD patients, and between changes in gastric myoelectrical activity and improvement in dyspeptic symptoms during Banha-sasim-tang administration.MethodsThis randomized, double-blind, placebo-controlled trial will be performed at two centers and will include a Banha-sasim-tang group and placebo group. Each group will consist of 50 FD patients. Six weeks of administration of Banha-sasim-tang or placebo will be conducted. During the subsequent 2 months, follow-up observations of primary and secondary outcomes will be performed. The primary outcomes are differences as measured on the gastrointestinal symptom scale, and the secondary outcomes are differences as measured on the visual analogue scale for dyspepsia and on the questionnaire for FD-related quality of life. All outcomes will be measured at baseline, at 2, 4, and 6 weeks of treatment, and at the 1 and 2 month follow-up. Cutaneous electrogastrography will be performed and assessed at baseline and at 6 weeks.DiscussionThis trial will provide evidence of the safety and efficacy of Banha-sasim-tang for the treatment for FD. Furthermore, based on the assessment of the relationship between cutaneous electrogastrography recordings and dyspeptic symptoms in this trial, the possibility of clinical applications of cutaneous electrogastrography in the treatment of FD will be elucidated.Trial RegistrationCurrent Controlled Trials (ISRCTN 51910678); Clinical Trials.gov Identifier: NCT00987805

Use of multichannel electrogastrography for noninvasive assessment of gastric myoelectrical activity in dogs

To evaluate whether changes in gastric myoelectrical activity in healthy, awake dogs can be detected via multichannel electrogastrography (EGG). 6 healthy hound-breed dogs. For each dog, 8-channel EGG was performed after food had been withheld for 12 hours and at 30 minutes after subsequent feeding; 60 minutes after feeding, atropine (0.04 mg/kg) was administered IM to induce ileus, and 30 minutes later, EGG was again performed. Mean cycles per minute (cpm) values of the dominant frequency (a measure of the rhythmicity of gastric electrical activity) and mean power ratios (ie, power measured after treatment divided by the power measured when food was withheld) were calculated. Motility of the gastric antrum was assessed via B-mode ultrasonography during the same phases; contractions determined ultrasonographically were correlated with EGG power for each channel in each phase. The criterion for stability (SD of the dominant frequency < 15% of the cpm value in at least 3 of the 8 EGG channels) was met in 4 of the 6 dogs (only in long-distance channels). The mean power ratios were significantly higher in the postprandial phase than in the ileus phase. Compared with the postprandial phase, significantly fewer contractions per minute were evident ultrasonographically in the ileus and food-withholding phases. There was a significant and good correlation between EGG power and ultrasonographic findings in all 8 channels. Electrogastrography may be useful in assessing gastric myoelectrical activities in awake dogs with naturally occurring gastrointestinal disease, including gastric dilatation-volvulus.

29 Burn‐induced GI dysmotility in severe burn injury

Introduction: Severe burn injury is known to delay gastric emptying in both animals and humans; however no data are available on its effect on gastric myoelectrical activity (GMA). We aimed at studying the effect of burn injury on GMA as it might contribute to burn‐induced delayed gastric emptying.Methods: Surgical implantation of a pair of cardiac pacemaker wires onto the stomach serosa was carried out in 20 adult male Sprague‐Dawley rats. Following recovery, GMA was recorded for 30 min in both fasting and fed conditions. The following day, rats received a sham or a 3rd degree scald burn injury under anesthesia. Proper fluid resuscitation and analgesia were given to all animals. Six hours after sham/burn injury, GMA was recorded for 30 min again in both fasting and fed conditions. A methylcellulose meal was mixed with phenol red (marker), so that the percentage of gastric emptying could be calculated based on the amount of phenol red recovered from the stomach. GMA parameters were computed using previously validated spectral analysis software developed in our laboratory, including dominant frequency/power and percentages of normal slow waves, bradygastria, tachygastria and arrhythmia. The normal slow wave frequency range was 4–6 cycles per min (cpm) in rats, while ≤4 cpm and ≥6 cpm were considered bradygastria and tachygastria respectively. Arrhythmia was established if the slow wave frequency had no specific range.Results: 1) None of GMA parameters showed any statistical differences in the fasting condition after burn (p &gt; 0.05). 2) Significant changes in GMA with burn were only observed postprandially, including: a decrease in dominant frequency (4.5 ± 0.2 vs. 5.1 ± 0.2, p = 0.002) and in the percentage of normal slow waves (67.2 ± 7.3 vs. 84.5 ± 4.1, p = 0.02) and an increase in the percentage of bradygastria (24.7 ± 6.8 vs. 9 ± 3.9, p = 0.02). 3) The percentage of gastric emptying was decreased after burn to 40.3 ± 6.5 vs. 77 ± 3.2 in previously obtained controls (p = 0.0003); however, it did not correlate significantly to any of GMA parameters before or after burn, whether in fasting or in fed conditions (p &gt; 0.05).Conclusion: Severe burn injury impairs both GMA and gastric emptying in rats. However, these alterations are not correlated with each other, suggesting that gastric dysrhythmia is a manifestation of burn rather than the cause of burn‐induced delayed gastric emptying.

Changes in gastric myoelectrical activity in hypertrophic pyloric stenosis and after surgical correction.

The changes of gastric myoelectrical activity were investigated in 20 infants by cutaneous electrogastrography (EGG) before and after the surgical correction of infantile hypertrophic pyloric stenosis (IHPS). The dominance of 2-4 cycles per minute (CPM) "slow waves" is typical of the healthy gastric function. The shift of the dominant frequencies towards the slower frequency (0-2 CPM) is defined as bradygastria, whereas a shift towards the more frequent waves (4-10 CPM) is called tachygastria. Unlike with healthy infants, the electrogastrogram showed pathologic patterns in 85% (18 out of 20) of IHPS patients. In all except two of these infants with pathologic electrical patterns, the frequency of the waves significantly shifted towards tachygastria. The effect of feeding on the gastric myoelectrical activity could only be studied in limited (9/20) cases because of recurring vomiting during the preoperative period. In IHPS infants, a significant increase in the bradygastria group was observed in the postprandial period compared with healthy infants. Three to 5 days after surgical repair (pyloromyotomy) and the reintroduction of feeding in gradually increasing amounts, the gastric myoelectrical activity showed physiologic patterns again, showing that the pyloric function was back to normal. Cutaneous EGG is a useful, noninvasive method to obtain indirect information about the motor function of the stomach and might be further applicable to pediatric gastric motility disorders.

Gastric myoelectrical activity in morbidly obese patients before and 3 months after gastric restrictive surgery.

Morbid obesity is often associated with gastrointestinal motor disorders. The aim of this study was to investigate gastric motility in morbid obesity, using electrogastrography (EGG) before and 3 months after gastric restrictive surgery. 40 morbidly obese subjects (age 40.6+/-10.3 years, BMI 46.4+/-5.7 kg/m2) were studied. VBG and Lap-Band operations were performed in 19 and 21 patients respectively. The following EGG-parameters were determined, both during fasting (f) and postprandially (pp): dominant frequency (DF(f/pp)), dominant power (DP(f/pp)), dominant frequency and power instability coefficient (DFIC and DPIC respectively) and power ratio. In the Lap-Band group, DF(pp), DP(pp) and DFIC(pp) were significantly higher compared with the preprandial state, both preoperatively and 3 months postoperatively. After VBG, DF(f) and DFIC(pp) were significantly lower and DPIC(f) significantly higher compared with the preoperative state. Furthermore, DF(pp) and DP(pp) were significantly higher than the preprandial values. However, in both types of operations, power ratio did not differ significantly between the preoperative and postoperative situation. Furthermore, no clear difference in EGG-parameters between both operations could be observed. After gastric restrictive surgery, no major changes in gastric myoelectrical activity occurred, suggesting that if clinical motility problems occur after bariatric surgery, they are not due to gastric myoelectrical dysfunction.

Perspectives of electrogastrography and motion sickness

Electrogastrography (EGG) is a noninvasive measurement of stomach activity using surface electrodes positioned over the abdominal surface. For over 10 years, EGG has been used as an objective measure of epigastric symptoms and nausea experienced in visually induced sickness provoked by circularvection. It was reported that during sickness, there is a shift in the dominant basal electrical activity. The 3 cycles per minute activity decrease and the 4–9 cycles per minute activity increase. This technique has also been used to evaluate the efficacy of antimotion sickness drugs and to monitor sickness induced by other provocative stimuli such as Coriolis cross-coupling, parabolic flight manoeuvres and microgravity. It has been further postulated that peripheral changes in gastric myoelectrical activity in response to visually induced sickness are detected centrally and lead to the generation of motion sickness. However, other studies using either identical or equally effective motion stimuli failed to support the positive correlation of changes in gastric activity with the incidence and severity of motion sickness. The interpretation of spectral analysis on EGG during motion sickness must be taken with great caution. The inherent variability of the EGG and intersubject variability makes it difficult to consider EGG a reliable and robust indicator of motion sickness. Its relation to motion sickness and the underlying mechanism remains unclear. The true diagnostic value of EGG in motion sickness has yet to be determined. Crown Copyright © 1999. Published by Elsevier Science Inc.

The effect of autonomic nervous system activity on gastric myoelectrical activity: does the spectral reserve hypothesis hold for the stomach?

Previous studies have associated changes in gastric myoelectrical activity during motion sickness, as indexed using the electrogastrogram (EGG), with changes in autonomic nervous system (ANS) activity. Subjects who did not report nausea in a rotating optokinetic drum were characterized by normal 3 cycles per minute (cpm) gastric myoelectrical activity, strong parasympathetic nervous system (PNS) activity, and low sympathetic nervous system (SNS) activity. The goals of this study were: (1) to determine whether tasks previously shown to alter ANS activity as indexed by changes in cardiac inter-beat intervals (IBIs) would result in systematic changes in gastric myoelectrical activity in accord with the findings from motion sickness studies; and (2) to determine whether the `spectral reserve hypothesis' applies to gastric myoelectrical activity. EGGs and IBIs were collected from 24 healthy subjects during resting/baseline, reaction time/shock-avoidance (RT) and cold face stress (CF) tasks. Tachyarrhythmia was found to be significantly greater during the RT task than during the baseline and CF tasks. It was concluded that: (1) tasks that alter ANS activity do systematically alter gastric myoelectrical activity; and (2) gastric myoelectrical activity does not follow the cardiac model of health being associated with increased spectral complexity.

Effects of highly selective vagotomy on gastric myoelectrical activity

Changes in gastric myoelectrical activity following highly selective vagotomy were studied in 12 patients by means of electrogastrography (EGG) using cutaneous electrodes. Measurements were made before, 10 days after, and six months after operation. Eight patients undergoing cholecystectomy served as controls. Preoperatively all controls and patients had normal recordings. In the cholecystectomized patients no significant changes were found postoperatively. Ten days after highly selective vagotomy the normal initial postprandial dip in gastric ECA frequency and the subsequent increase in frequency and power were not seen. Tachygastrias were observed in three patients. Six months after operation the normal frequency and power responses to a test meal had returned, but both the fasting and postprandial ECA frequencies were raised significantly. It is concluded that highly selective vagotomy is associated with abnormalities in myoelectrical activity, in particular in the postprandial state, most of which are reversible with time.