Pulsed-field ablation does not induce esophageal and periesophageal injury-A new esophageal safety paradigm in catheter ablation of atrial fibrillation.

INTRODUCTION: Esophageal injury is one of the most serious complications of pulmonary vein isolation (PVI) with thermic energy sources. Better tissue selectivity of primarily non-thermic pulsed field ablation (PFA) may eliminate collateral injury, particularly the risk of atrio-esophageal fistula (AEF). OBJECTIVE: To compare the incidence of any (peri)-esophageal injury following PVI using PFA to thermic energy sources. METHODS: Using endoscopy, endoscopic ultrasound, and electrogastrography before and after PVI, esophageal and periesophageal injury (mucosal lesions, food retention, periesophageal edema, or vagal nerve injury) were assessed following PFA and radiofrequency (RF)- or cryoballoon (CB)-PVI. RESULTS: Between December 2022 and February 2023, 20 patients (67 ± 10 years, 53% male) undergoing PFA (Farapulse, Boston Scientific) for atrial fibrillation (AF) were studied and compared with a previous cohort of 57 patients who underwent thermic PVI (CB: n = 33; RF: n = 24). Following PFA-PVI, none of the patients had mucosal lesions, food retention, or ablation-induced vagal nerve injury; four patients showed periesophageal edema. Following thermic ablation, 33/57 patients (58%) showed esophageal and/or periesophageal injury (CB: 21/33 [64%], RF: 12/24 [50%]), in detail 4/57 mucosal lesions, 18/57 food retention, 17/57 vagal nerve injury, and 20/52 edema. Midterm success rates were similar for all energy sources. CONCLUSION: In contrast to thermic ablation tools, PFA is not associated with relevant esophageal and periesophageal injury, and might, therefore, reduce or eliminate the risk of potentially lethal AEF in interventional treatment of AF. The etiology of ablation-induced periesophageal edema is unknown but has not been shown to be related to lesion progression.

Antibiotic duration and gastric dysmotility in preterm neonates.

OBJECTIVES: Prolonged antibiotic use after birth is associated with neonatal feeding intolerance and functional gastrointestinal disorders (FGIDs). A gastric dysrhythmia (tachygastria) with frequencies >4-9 cycles per minute, measured by electrogastrography (EGG), is associated with FGIDs. The relationship between prolonged antibiotic use and % time spent in tachygastria is unknown in preterm infants. We aimed to compare weekly changes in % tachygastria between preterm infants receiving long (>48 h) versus short (≤48 h) courses of antibiotics for early onset sepsis evaluation (initiated at <3 days of life). METHODS: This was a longitudinal, prospective cohort study of 88 preterm infants (<34 weeks' gestation) with weekly EGG recordings from the first week of life until 40 weeks' post-menstrual age, discharge, or death. We calculated % of EGG recording time in tachygastria and determined the mean across weekly sessions. A mixed effects model assessed variance in % tachygastria between the short- and long-antibiotic exposure groups across all weeks. RESULTS: Baseline characteristics were similar between the two groups. There was no difference in % tachygastria between short and long antibiotic exposure groups across nine postnatal weeks (p = 0.08). CONCLUSIONS: Early, prolonged antibiotic exposure among preterm infants may not lead to significant gastric dysrhythmia. Future studies including larger sample sizes and a "no antibiotic" exposure arm are essential in elucidating this potential relationship.

Reliability and validity of brain-gastric phase synchronization.

Recent studies have reported that various brain regions, mainly sensory, unimodal regions, display phase synchronization with the stomach's slow (0.05 Hz) myoelectrical rhythm. These gastric-brain interactions have broad implications, from feeding behavior to functional gastrointestinal disorders. However, in contrast to other interoceptive signals (e.g., heart rate) and their relation to the brain, little is known about the reliability of these gastric-brain interactions, their robustness to artifacts such as motion, and whether they can be generalized to new samples. Here we examined these aspects in 43 subjects that had undergone multiple runs of concurrent electrogastrography (EGG), brain fMRI, and pulse oximetry. We also repeated all analyses in an open dataset of a highly sampled individual. We found a set of brain regions that were coupled with the EGG signal after controlling for non-grey matter (GM) signals, head motion, and cardiac artifacts. These regions exhibited significant overlap with previous work. However, we also showed that prior to confound regression, the spatial extent of the gastric network was largely overestimated. Finally, we found substantial test-retest reliability in both the brain and the gastric signals when estimated alone, but not for measures of gastric-brain synchrony. Together, these results provide methodological scaffolding for future research into brain-stomach interactions and for a better understanding of the role of the gastric network.

Pulmonary vein isolation-induced vagal nerve injury and gastric motility disorders detected by electrogastrography: The side effects of pulmonary vein isolation in atrial fibrillation (SEPIA) study.

INTRODUCTION: Safety of pulmonary vein isolation (PVI) has been established in clinical studies. However, despite prevention efforts the incidence of damage to (peri)-esophageal tissue has not decreased, and the pathophysiology is incompletely understood. Damage to vagal nerve branches may be involved in lesion progression to atrio-esophageal fistula. Using electrogastrography, we assessed the incidence of periesophageal vagal nerve injury (VNI) following atrial fibrillation ablation and its association with procedural parameters and endoscopic results. METHODS: Patients were studied using electrogastrography, endoscopy, and endoscopic ultrasound before and after cryoballoon (CB) or radiofrequency (RF) PVI. The incidence of ablation-induced neuropathic pattern (indicating VNI) in pre- and postprocedural electrogastrography was assessed and correlated with endoscopic results and ablation data. RESULTS: Between February 2021 und January 2022, 85 patients (67 ± 10 years, 53% male) were included, 33 were treated with CB and 52 with RF (38 with moderate power moderate duration [25-30 W] and 14 with high power short duration [50 W]). Ablation-induced VNI was detected in 27/85 patients independent of the energy form. Patients with VNI more frequently had postprocedural endoscopically detected pathology (8% mucosal esophageal lesions, 36% periesophageal edema, 33% food retention) but there was incomplete overlap. Pre-existing esophagitis increased the likelihood of VNI. Ablation data and esophageal temperature data did not predict VNI. CONCLUSION: PVI-induced VNI is quite common and independent of ablation energy source. VNI is part of (peri)-esophageal damage and only partially overlaps with endoscopic findings. VNI-associated acidic reflux may be involved in the complex pathophysiology of esophageal lesion progression to fistula.

Gastric myoelectrical activity based AI-derived threshold predicts resolution of gastroparesis post-pyloric balloon dilation.

BACKGROUND: A patient subset with gastroparesis (GP) has normal gastric myoelectrical activity (GMA) and pyloric dysfunction. AIMS: (1) To determine pyloric balloon dilation (BD) effect on symptoms and gastric emptying in GP patients with normal 3 cycles per minute (cpm) GMA. (2) To demonstrate GMA-based artificial intelligence (AI)-derived formulae predict BD success at 10-12-month follow-up. METHODS: Cohort subjects completed baseline electrogastrogram w/water load satiety test (WLST), solid-phase nuclear gastric emptying, Gastrointestinal Cardinal Symptom Index (ANMS GCSI-DD) and Leeds questionnaires. Subjects were divided into two groups based on response to the WLST. Group 1 (n = 26) with hypernormal/normal 3 cpm GMA and Group 2 (n = 4) hyponormal/normal range 3 cpm GMA, compared to healthy normals. All subjects underwent endoscopic pyloric BD. After 10-12 months, gastric emptying and dyspepsia questionnaires were repeated to evaluate outcomes. RESULTS: Group 1 ANMS GCSI-DD scores improved from 2 points at baseline (BL) to 0 at follow-up (f/u) (p < 0.001); Group 2 ANMS GSCI-DD scores were 2 at BL and 1.6 at f/u (p = 0.25). Leeds scores improved (p < 0.001) only for Group 1. Group 1 gastric emptying improved (54.5% retained at 2 h at BL vs. 12.2% at f/u, p < 0.001) in contrast to Group 2 patients (51.25% at BL vs. 56.25% at f/u, p = 0.252). Percentage 3 cpm GMA decreased (41.1% at BL vs. 24.9% at f/u, p ≤ 0.005) in Group 1 versus Group 2 (15.3% at BL vs. 23.4% at f/u, p = 0.114). AI-derived GMA threshold (GMAT) of 0.59 predicted positive pyloric BD outcomes at 10-12 months with sensitivity 96%, specificity 75%, and 93% correct classification. CONCLUSIONS: Pyloric BD improved symptoms and gastric emptying long term in patients with GP and hypernormal/normal 3 cpm GMA. AI-derived GMAT predicted pyloric BD success. GMA post-WLST and GMAT are objective measures for improved selection and outcomes for endoscopic pyloric BD.

Gut-Brain Coupling and Multilevel Physiological Response to Biofeedback Relaxation After a Stressful Task Under Virtual Reality Immersion: A Pilot Study.

Human physiological reactions to the environment are coordinated by the interactions between brain and viscera. In particular, the brain, heart, and gastrointestinal tract coordinate with each other to provide physiological equilibrium by involving the central, autonomic, and enteric nervous systems. Recent studies have demonstrated an electrophysiological coupling between the gastrointestinal tract and the brain (gut-brain axis) under resting-state conditions. As the gut-brain axis plays a key role in individual stress regulation, we aimed to examine modulation of gut-brain coupling through the use of an overwhelming and a relaxing module as a first step toward modeling of the underlying mechanisms. This study was performed in 12 participants who, under a virtual reality environment, performed a 9-min cognitive stressful task followed by a 9-min period of relaxation. Brain activity was captured by electroencephalography, autonomic activities by photoplethysmography, and electrodermal and gastric activities by electrogastrography. Results showed that compared with the stressful task, relaxation induced a significant decrease in both tonic and phasic sympathetic activity, with an increase in brain alpha power and a decrease in delta power. The intensity of gut-brain coupling, as assessed by the modulation index of the phase-amplitude coupling between the normogastric slow waves and the brain alpha waves, decreased under the relaxation relative to the stress condition. These results highlight the modulatory effect of biofeedback relaxation on gut-brain coupling and suggest noninvasive multilevel electrophysiology as a promising way to investigate the mechanisms underlying gut-brain coupling in physiological and pathological situations.

Validation of noninvasive body-surface gastric mapping for detecting gastric slow-wave spatiotemporal features by simultaneous serosal mapping in porcine.

Gastric disorders are increasingly prevalent, but reliable noninvasive tools to objectively assess gastric function are lacking. Body-surface gastric mapping (BSGM) is a noninvasive method for the detection of gastric electrophysiological features, which are correlated with symptoms in patients with gastroparesis and functional dyspepsia. Previous studies have validated the relationship between serosal and cutaneous recordings from limited number of channels. This study aimed to comprehensively evaluate the basis of BSGM from 64 cutaneous channels and reliably identify spatial biomarkers associated with slow-wave dysrhythmias. High-resolution electrode arrays were placed to simultaneously capture slow waves from the gastric serosa (32 × 6 electrodes at 4 mm spacing) and epigastrium (8 × 8 electrodes at 20 mm spacing) in 14 porcine subjects. BSGM signals were processed based on a combination of wavelet and phase information analyses. A total of 1,185 individual cycles of slow waves were assessed, out of which 897 (76%) were classified as normal antegrade waves, occurring in 10 (71%) subjects studied. BSGM accurately detected the underlying slow wave in terms of frequency (r = 0.99, P = 0.43) as well as the direction of propagation (P = 0.41, F-measure: 0.92). In addition, the cycle-by-cycle match between BSGM and transitions of gastric slow wave dysrhythmias was demonstrated. These results validate BSGM as a suitable method for noninvasively and accurately detecting gastric slow-wave spatiotemporal profiles from the body surface.NEW & NOTEWORTHY Gastric dysfunctions are associated with abnormalities in the gastric bioelectrical slow waves. Noninvasive detection of gastric slow waves from the body surface can be achieved through multichannel, high-resolution, body-surface gastric mapping (BSGM). BSGM matched the spatiotemporal characteristics of gastric slow waves recorded directly and simultaneously from the serosal surface of the stomach. Abnormal gastric slow waves, such as retrograde propagation, ectopic pacemaker, and colliding wavefronts can be detected by changes in the phase of BSGM.

Aberrant gastric functioning in weight-restored but not acute restricting-type anorexia nervosa: An electrogastrography study.

OBJECTIVE: Individuals with anorexia nervosa (AN) have high levels of gastrointestinal (GI) symptoms, functional GI disorders, and alterations in interoception. The primary aims of the current study were to determine (1) whether individuals with AN differed in gastric physiology as measured by electrogastrography (EGG) as compared to healthy individuals and (2) whether their EGG activity changed from pre- to post-weight restoration. METHOD: Adolescent and young adult females receiving inpatient treatment for restricting-type AN (n = 20) and healthy control females (n = 21) completed two EGG sessions, with measurements taken in fasting state and after administration of a water load. Participants with AN completed the first session while underweight and the second session following weight restoration. Healthy control participants also completed two sessions matched for length of time between sessions. RESULTS: Participants with AN exhibited decreased normogastria post-water load when they were weight restored compared to when they were underweight. Healthy control participants' EGG measures were stable across sessions. DISCUSSION: Findings provide evidence for aberrant gastric physiology in individuals with AN who have been weight restored, but not those in the acute phase of the illness. This supports the need for further research on GI functioning in AN. PUBLIC SIGNIFICANCE: Anorexia nervosa (AN) is a highly debilitating eating disorder that is difficult to treat. The causes of AN are largely unknown, but some theories suggest problems in gastrointestinal functioning may contribute to the disorder. This study found aberrant gastric functioning in individuals diagnosed with AN after weight restoration treatment. These findings contribute to our understanding of the causes and maintenance of AN and may ultimately lead to better treatments.

Abnormalities on Electrogastrography in Nausea and Vomiting Syndromes: A Systematic Review, Meta-Analysis, and Comparison to Other Gastric Disorders.

BACKGROUND: Functional nausea and vomiting syndromes and gastroparesis, collectively grouped as nausea and vomiting syndromes (NVS), are overlapping conditions with incompletely understood pathophysiology. Gastric slow wave abnormalities are thought to contribute. AIMS: This study aimed to systematically review and meta-analyze the prevalence of slow wave abnormalities measured by electrogastrography (EGG) in patients with NVS. METHODS: MEDLINE, EMBASE, EMBASE classic, and CENTRAL databases were systematically searched for articles using EGG in adults (≥ 18 years) with NVS. EGG metrics of interest were percentage time in bradygastria, normogastria, and tachygastria as well as dominant frequency and dominant power. Outcomes were also compared with functional dyspepsia (FD), gastroesophageal reflux disease (GORD), and control cohorts. RESULTS: Seven hundred and sixty NVS patients and 308 controls were included from 24 studies. Overall, 64% of patients had EGG abnormalities. Average percent time in normogastria was low during fasting (50%; 95% CI 40-63%) and fed (53%; 95% CI 41-68%) states in patients, with substantial periods in fasting bradygastria (34.1%; 95% CI 25-47%) and postprandial tachygastria (21%; 95% CI 17-26%). Across gastric disorders, pooling of 84 studies showed a comparably high prevalence of EGG abnormalities in NVS (24 studies; n = 760) and GORD (13 studies; n = 427), compared to FD (47 studies; n = 1751) and controls (45 studies; n = 1027). CONCLUSIONS: Frequency-based gastric slow wave abnormalities are prominent in NVS. The strength and consistency of these associations across many studies suggests that gastric dysrhythmia may be an important factor in NVS, motivating the development of more reliable methods for their clinical assessment.

Analysis of Diagnostic Value of Electrogastrography for Parkinson's Disease and its Predictive Value for the Disease Progression.

The study aimed to evaluate the diagnostic and prognostic value of indexes detected by electrogastrography in Parkinson's disease patients. One hundred twenty early Parkinson's disease patients and 120 healthy controls were recruited, and underwent electrogastrography to detect dominant frequency (DF), instability coefficient of DF (ICDF), low frequency range (LFR), high frequency range (HFR), and normal frequency range (NFR). The receiver operating characteristic (ROC) curve was drawn for the diagnostic value analysis. The motor function was scored with the Unified Parkinson's Disease Rating Scale (UPDRS). Sniffin' Sticks test was used for the olfactory evaluation, and the TDI score consisting of odor threshold (T), odor discrimination (D) and odor identification (I) tests was calculated. The preprandial ICDF of Parkinson's disease patients was significantly higher than that of the control group, and decreased slowly during the late postprandial phase. The levels of LFR%, HFR% and NFR% in Parkinson's disease patients were higher than the control group during both the preprandial and late postprandial phase, and the changes of each index before and after meals were not obvious. Preprandial ICDF value and TDI score had the ability to distinguish Parkinson's disease patients with the AUC of 0.874 and 0.859 respectively. The ICDF detected by electrogastrography has high clinical value in the early diagnosis of Parkinson's disease, and the combination of ICDF and TDI can improve the diagnostic sensitivity and specificity of a single indicator. High ICDF levels during the preprandial phase are related to the poor prognosis of Parkinson's disease patients after treatment.

Simultaneous Gut-Brain Electrophysiology Shows Cognition and Satiety Specific Coupling.

Recent studies, using high resolution magnetoencephalography (MEG) and electrogastrography (EGG), have shown that during resting state, rhythmic gastric physiological signals are linked with cortical brain oscillations. Yet, gut-brain coupling has not been investigated with electroencephalography (EEG) during cognitive brain engagement or during hunger-related gut engagement. In this study in 14 young adults (7 females, mean ± SD age 25.71 ± 8.32 years), we study gut-brain coupling using simultaneous EEG and EGG during hunger and satiety states measured in separate visits, and compare responses both while resting as well as during a cognitively demanding working memory task. We find that EGG-EEG phase-amplitude coupling (PAC) differs based on both satiety state and cognitive effort, with greater PAC modulation observed in the resting state relative to working memory. We find a significant interaction between gut satiation levels and cognitive states in the left fronto-central brain region, with larger cognitive demand based differences in the hunger state. Furthermore, strength of PAC correlated with behavioral performance during the working memory task. Altogether, these results highlight the role of gut-brain interactions in cognition and demonstrate the feasibility of these recordings using scalable sensors.

Electrogastrogram-Derived Features for Automated Sickness Detection in Driving Simulator.

The rapid development of driving simulators for the evaluation of automated driving experience is constrained by the simulator sickness-related nausea. The electrogastrogram (EGG)-based approach may be promising for immediate, objective, and quantitative nausea assessment. Given the relatively high EGG sensitivity to noises associated with the relatively low amplitude and frequency spans, we introduce an automated procedure comprising statistical analysis and machine learning techniques for EGG-based nausea detection in relation to the noise contamination during automated driving simulation. We calculate the root mean square of EGG amplitude, median and dominant frequencies, magnitude of Power Spectral Density (PSD) at dominant frequency, crest factor of PSD, and spectral variation distribution along with newly introduced parameters: sample and spectral entropy, autocorrelation zero-crossing, and parameters derived from the Poincaré diagram of consecutive EGG samples. Results showed outstanding robustness of sample entropy with moderate robustness of autocorrelation zero-crossing, dominant frequency, and its median. Machine learning reached an accuracy of 88.2% and revealed sample entropy as one of the most relevant and robust parameters, while linear analysis highlighted spectral entropy, spectral variation distribution, and crest factor of PSD. This study clearly indicates the need for customized feature selection in noisy environments, as well as a complementary approach comprising machine learning and statistical analysis for efficient nausea detection.

Does maladaptive cardiovagal modulation extend to gastric modulation in women with chronic pelvic pain?

BACKGROUND: Women with chronic pelvic pain (CPP) have poor cardiovagal modulation. It is unclear whether this finding reflects a broader abnormality across many systems such as gastro-vagal modulation. AIM: To determine if maladaptive cardiovagal activity in females with CPP is accompanied by maladaptive gastric myoelectric activity. METHODS: A total of 36 health controls (HC) and 75 CPP underwent supine (10 min), then upright (tilted 70° head up; 30 min), and back to supine (10 min) positions. High-frequency heart rate variability (HF-HRV; 0.15-0.4 Hz) was measured as an index of cardiovagal activity. Cutaneous electrogastrography (EGG) assessed gastric myoelectric activity pre- and during-upright tilt. EGG measures from 16 HC and 31 CPP patients were available for analysis and included relative percentage of gastric activity within the normal (2-4 cpm) and tachygastria (4-10 cpm) ranges, plus ratio of normal/tachygastria. RESULTS: HF-HRV was lower in CPP individuals at all time points (each p < .05). CPP individuals showed lesser decrease in HF-HRV from supine to upright, and poorer HF-HRV recovery from upright back to supine (F[1, 106] = 4.62, p = .034). HC showed increase in tachygastria activity (t[15] = -2.09, p = .054) while the CPP group showed no change in tachygastria activity from pre-upright to upright (t[30] = -0.62, p = .537). CONCLUSIONS: Individuals with CPP going from supine to upright demonstrate an impairment in both tachygastria and the parallel decrement in HRV. These results support the hypothesis of a generalized blunting in the physiological modulation in CPP individuals affecting both cardiovascular and gastric systems.

Gastric interoception and gastric myoelectrical activity in bulimia nervosa and binge-eating disorder.

OBJECTIVE: Identifying factors that control food intake is crucial to the understanding and treatment of eating disorders characterized by binge eating. In healthy individuals, stomach distension plays an important role in the development of satiation, but gastric sensations might be overridden in binge eating. The present study investigated the perception of gastric signals (i.e., gastric interoception) and gastric motility in patients experiencing binge-eating episodes, that is, bulimia nervosa (BN) and binge-eating disorder (BED). METHOD: Twenty-nine patients with BN or BED (ED group) and 32 age-, sex-, and BMI-matched healthy controls (HC group) participated in the study. The onset of satiation and stomach fullness were assessed using a novel 2-step water load test (WLT-II). Gastric myoelectrical activity (GMA) was measured by electrogastrography (EGG) before and after ingestion of noncaloric water. RESULTS: Individuals in the ED group drank significantly more water until reporting satiation during the WLT-II. The percentage of normal gastric myoelectrical power was significantly smaller in the ED group compared to HC, and negatively related to the number of objective binge-eating episodes per week in patients with BN or BED. Power in the bradygastria range was greater in ED than in HC participants. DISCUSSION: Patients with EDs have a delayed response to satiation compared to HC participants, together with abnormal GMA. Repeated binge-eating episodes may induce disturbances to gastric motor function.

Advanced Bioelectrical Signal Processing Methods: Past, Present, and Future Approach-Part III: Other Biosignals.

Analysis of biomedical signals is a very challenging task involving implementation of various advanced signal processing methods. This area is rapidly developing. This paper is a Part III paper, where the most popular and efficient digital signal processing methods are presented. This paper covers the following bioelectrical signals and their processing methods: electromyography (EMG), electroneurography (ENG), electrogastrography (EGG), electrooculography (EOG), electroretinography (ERG), and electrohysterography (EHG).

Electrogastrography in Autonomous Vehicles-An Objective Method for Assessment of Motion Sickness in Simulated Driving Environments.

Autonomous vehicles are expected to take complete control of the driving process, enabling the former drivers to act as passengers only. This could lead to increased sickness as they can be engaged in tasks other than driving. Adopting different sickness mitigation techniques gives us unique types of motion sickness in autonomous vehicles to be studied. In this paper, we report on a study where we explored the possibilities of assessing motion sickness with electrogastrography (EGG), a non-invasive method used to measure the myoelectric activity of the stomach, and its potential usage in autonomous vehicles (AVs). The study was conducted in a high-fidelity driving simulator with a virtual reality (VR) headset. There separate EGG measurements were performed: before, during and after the driving AV simulation video in VR. During the driving, the participants encountered two driving environments: a straight and less dynamic highway road and a highly dynamic and curvy countryside road. The EGG signal was recorded with a proprietary 3-channel recording device and Ag/AgCl cutaneous electrodes. In addition, participants were asked to signalize whenever they felt uncomfortable and nauseated by pressing a special button. After the drive they completed also the Simulator Sickness Questionnaire (SSQ) and reported on their overall subjective perception of sickness symptoms. The EGG results showed a significant increase of the dominant frequency (DF) and the percentage of the high power spectrum density (FSD) as well as a significant decrease of the power spectrum density Crest factor (CF) during the AV simulation. The vast majority of participants reported nausea during more dynamic conditions, accompanied by an increase in the amplitude and the RMS value of EGG. Reported nausea occurred simultaneously with the increase in EGG amplitude. Based on the results, we conclude that EGG could be used for assessment of motion sickness in autonomous vehicles. DF, CF and FSD can be used as overall sickness indicators, while the relative increase in amplitude of EGG signal and duration of that increase can be used as short-term sickness indicators where the driving environment may affect the driver.

The Impact of Dextran Sodium Sulfate-Induced Gastrointestinal Injury on the Pharmacokinetic Parameters of Donepezil and Its Active Metabolite 6-O-desmethyldonepezil, and Gastric Myoelectric Activity in Experimental Pigs.

Gastrointestinal side effects of donepezil, including dyspepsia, nausea, vomiting or diarrhea, occur in 20-30% of patients. The pathogenesis of these dysmotility associated disorders has not been fully clarified yet. Pharmacokinetic parameters of donepezil and its active metabolite 6-O-desmethyldonepezil were investigated in experimental pigs with and without small intestinal injury induced by dextran sodium sulfate (DSS). Morphological features of this injury were evaluated by a video capsule endoscopy. The effect of a single and repeated doses of donepezil on gastric myoelectric activity was assessed. Both DSS-induced small intestinal injury and prolonged small intestinal transit time caused higher plasma concentrations of donepezil in experimental pigs. This has an important implication for clinical practice in humans, with a need to reduce doses of the drug if an underlying gastrointestinal disease is present. Donepezil had an undesirable impact on porcine myoelectric activity. This effect was further aggravated by DSS-induced small intestinal injury. These findings can explain donepezil-associated dyspepsia in humans.

The effect of ginger (Zingiber officinale Roscoe) in patients with advanced cancer.

BACKGROUND: Anorexia-cachexia syndrome (ACS) is a complex condition in advanced cancer patients, defined by disproportionate loss of skeletal muscle mass, and a lack or loss of appetite. This condition greatly lowers the quality of life and limits the treatment options. ACS is commonly associated with gastrointestinal symptoms such as nausea and vomiting. Ginger has been successful in treating these symptoms but has not yet been tested on patients with advanced cancer. Electrogastrography is a technology that allows the direct recording of the gastric myoelectrical activity (GMA). PURPOSE: The aim of this study is to (1) determine the effects of ginger on the GMA in these patients, (2) evaluate the subjective symptoms using 3 validated scales, and (3) correlate the level of inflammatory factors and ghrelin in this patient population. METHODS: Patients with ACS and advanced cancer were recruited from the Palliative Rehabilitation outpatient program at Elisabeth Bruyère Hospital. Patients were instructed to take a daily capsule of 1650 mg of ginger for 14 days and outcome measures were recorded at pre- and post-intervention, which included a blood test for analysis of CRP, albumin and ghrelin levels, 3 self-administered surveys (DSSI, PG-SGA, ESAS), patient-reported symptoms, and an EGG diagnosis. RESULTS: Fifteen patients with a median age of 58 and varying cancer diagnoses were enrolled. EGG diagnosis showed that 9 of the 15 patients had a direct improvement in their GMA, and all patients showed improvement in reported symptoms, most notably nausea, dysmotility- and reflux-like symptoms. There was no correlation found for ginger administration and inflammatory factors. CONCLUSION: These findings suggest that ginger may improve GMA as measured by EGG and may have a notable effect on symptom improvement.

Heart Rate Variability and Gastric Electrical Response to a Cold Pressor Task in Youth with Functional Dyspepsia.

BACKGROUND/AIMS: While stress has been implicated in functional dyspepsia (FD), the mechanisms by which stress results in symptoms are not well defined. The aim of the current study was to assess gastric myoelectric and autonomic changes in response to a physical stressor in youth with FD. METHODS: In a group of healthy controls and pediatric FD subjects, we recorded ECG and EGG signals 30 min before and 60 min after, a cold pressor task (CPT). Gastric EGG and heart rate variability (HRV) parameters were calculated in pre- and post-CPT stages and in short intervals. RESULTS: The pre-CPT percent tachygastria was higher in FD subjects as compared to controls. However, CPT did not induce any EGG changes in either controls or FD subjects and the two groups did not differ from each other post-CPT. The CPT resulted in an increase in HRV and standard deviation of NN intervals in controls; there was no change in any HRV parameter in FD subjects. CONCLUSIONS: Acute physical stress does not appear to induce gastric electrical abnormalities in youth with FD. Youth with FD appear to lack the normal flexible autonomic response to a physical stressor.

Lessons Learned: Gastric Motility Assessment During Driving Simulation.

In the era of technological advances and innovations in transportation technologies, application of driving simulators for the investigation and assessment of the driving process provides a safe and suitable testing environment. Although driving simulators are crucial for further improvements in transportation, it is important to resolve one of their main disadvantages-simulator sickness. Therefore, suitable methods for the assessment of simulator sickness are required. The main aim of this paper was to present a non-invasive method for assessing simulator sickness by recording gastric myoelectrical activity-electrogastrography. Open-source hardware for electrogastrography together with recordings obtained in 13 healthy volunteers is presented, and the main aspects of signal processing for artifact cancellation and feature extraction were discussed. Based on the obtained results, it was concluded that slow-wave electrical gastric activity can be recorded during driving simulation by following adequate recommendations and that proposed features could be beneficial in describing non-ordinary electrogastrography signals.