Electrogastrogram Research Articles

Short- and long-term reproducibility of body surface gastric mapping using the Gastric Alimetry® system.

Many diagnostic tests for gastroduodenal symptoms, such as gastric emptying scintigraphy (GES), gastric emptying breath tests (GEBT), and electrogastrography (EGG) show variable intra-individual reproducibility over time. This study investigated the short- and long-term reproducibility of body surface gastric mapping (BSGM), a non-invasive test for assessing gastric function, in controls and patients with chronic gastroduodenal disorders. Participants completed three standardized BSGM tests using Gastric Alimetry® (Alimetry, New Zealand). The test encompassed a fasting baseline (30 min), a 482 kCal standard meal, and a 4 h postprandial recording. The first two tests were >6 months apart and the last occurred ~1 week after the second test, to evaluate long and short-term reproducibility. Fourteen patients with upper gastrointestinal symptoms and 14 healthy controls were recruited. There were no significant differences in any BSGM metrics between the tests at short and long term (all p > 0.180). Lin's concordance correlation coefficients (CCC) for the primary metrics were high, ranging from 0.58 to 0.96, with intra-individual coefficients of variance (CVintra) ranging from 0.2% to 1.9%. Reproducibility was higher, and intra-individual variation lower, than in previous studies of GES (CCC = 0.54-0.83, CVintra = 3%-77%), GEBT (CVintra = 8%-11%), and EGG (CVintra = 3%-78%). BSGM spectral metrics demonstrate high reproducibility and low intra-individual variation at both short and long term, with superior results to comparable tests. The high reproducibility of Gastric Alimetry supports its role as a diagnostic aid for gastric dysfunction and a reliable tool for evaluating treatment outcomes and disease progression over time.

Electrogastrography measurement systems and analysis methods used in clinical practice and research: comprehensive review.

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A Case Report of Korean Medical Treatment for an Adult with Cyclic Vomiting Syndrome Analyzed by Electrogastrography and Subjective Evaluation Scale

Objectives: This case study reports the effectiveness of Korean medical treatment in a patient with cyclic vomiting syndrome.Methods: A 29-year-old female Korean patient with cyclic vomiting syndrome received acupuncture, electroacupuncture, herbal medicine, and moxibustion for 2 weeks in hospital. Changes in symptoms were evaluated using the Gastrointestinal Symptom Rating Scale (GSRS), Visual Analog Scale (VAS), Index for Nausea, Vomiting, and Retching (INVR), Nausea Severity Scale (NSS), Nepean Dyspepsia Index-Korean version (NDI-K), quality of life using the Functional Dyspepsia Related Quality of Life questionnaire (FD-QoL), and gastric motility using electrogastrography (EGG).Results: Post-treatment, the patient showed high satisfaction and improvement in symptoms of nausea and vomiting. The following changes were observed in scores: GSRS: 23 to 19; VAS of nausea: 88 to 95; VAS of dyspepsia: 95 to 12; INVR: 13 to 1; NSS: 17 to 5; NDI-K: 107 to 78; and FD-QoL 84 to 27. We also found positive results in Channel 3 of EGG parameters, implying the improvement of gastric motility disorder.Conclusion: Korean medical treatment can be a therapeutic option for cyclic vomiting syndrome.

Analysis of gastric electrical rhythm in patients with type 2 diabetes mellitus

AimTo analysis the change of electrogastrogram (EGG) in patients with type 2 diabetes mellitus (T2DM), and evaluate the prevalence of abnormal gastric electrical rhythm (AGER) and its relative influencing factors.MethodsA total of 65 patients with T2DM hospitalized at the Second Affiliated Hospital of Soochow University from Dec. 2020 to Dec. 2021 were included in the cross-sectional study. General information, clinical data, and medical history data of all study subjects, including name, gender, body mass index (BMI), duration of diabetes, anti-diabetic therapies, high blood pressure (HBP) history, smoking history, and medication history, were completely collected. The results of laboratory tests, including biochemical parameters, glycosylated hemoglobin (HbA1c), fasting C-peptide, 2 h postprandial C-peptide, 24 h urine total protein (24 hUTP), urine microalbumin creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) were recorded. EGG, Gastroparesis Cardinal Symptom Index (GCSI), gastric emptying ultrasound, fundus examination, carotid artery ultrasonography, cardiac autonomic function test, heart rate variability (HRV) were all examined and recorded as well. According to the results of EGG, the subjects were divided into normal gastric electrical rhythm (NGER) group and abnormal gastric electrical rhythm (AGER) group.Results(1) Fasting blood glucose (FBG), HbA1c, the presence of diabetic peripheral neuropathy (DPN) and diabetic cardiac autonomic neuropathy (DCAN) were significantly higher in the AGER group (p < 0.05). Low frequency (LF) and high frequency (HF), the indicators of HRV, were significantly lower in the AGER group (p < 0.05). In addition, the prevalence of feeling excessively full after meals, loss of appetite, and stomach or belly visibly larger after meals of gastrointestinal symptoms of gastroparesis were significantly higher in the AGER group (p < 0.05). Multiple logistic regression analysis showed that FBG and the prevalence of DCAN were the independent risk factors.ConclusionAGER was associated with high FBG and the presence of DCAN. EGG examination is recommended for patients with gastrointestinal symptoms and clues of DCAN.

Data augmentation for generating synthetic electrogastrogram time series

To address an emerging need for large number of diverse datasets for rigor evaluation of signal processing techniques, we developed and evaluated a new method for generating synthetic electrogastrogram time series. We used electrogastrography (EGG) data from an open database to set model parameters and statistical tests to evaluate synthesized data. Additionally, we illustrated method customization for generating artificial EGG time series alterations caused by the simulator sickness. Proposed data augmentation method generates synthetic EGG data with specified duration, sampling frequency, recording state (postprandial or fasting state), overall noise and breathing artifact injection, and pauses in the gastric rhythm (arrhythmia occurrence) with statistically significant difference between postprandial and fasting states in > 70% cases while not accounting for individual differences. Features obtained from the synthetic EGG signal resembling simulator sickness occurrence displayed expected trends. The code for generation of synthetic EGG time series is not only freely available and can be further customized to assess signal processing algorithms but also may be used to increase data diversity for training artificial intelligence (AI) algorithms. The proposed approach is customized for EGG data synthesis but can be easily utilized for other biosignals with similar nature such as electroencephalogram.Graphical abstract

Antibiotic duration and gastric dysmotility in preterm neonates.

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). 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. 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). 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.

Difference in Cyclic Versus Non-cyclic Symptom Patterns in Patients with the Symptoms of Gastroparesis Undergoing Bioelectric Therapy.

Patients with gastroparesis (Gp) have symptoms with or without a cyclic pattern. This retrospective study evaluates differences in cyclic vs. non-cyclic symptoms of Gp by analyzing mucosal electrogastrogram (mEG), familial dysautonomias, and response to gastric stimulation. 37 patients with drug refractory Gp, 7 male and 30 female, with a mean age of 41.4years, were studied. 18 had diabetes mellitus, 25 had cyclic (Cyc), and 12 had a non-cyclic (NoCyc) pattern of symptoms. Patients underwent temporary mucosal gastric stimulator (tGES) placement, which was done as a trial before permanent stimulator (GES) placement. Electrogastrogram (EGG) by mucosal (mEG) measures, including frequency, amplitude, and frequency-amplitude ratio (FAR), were pre- and post-tGES. Patients' history of personal and familial dysautonomias, quality of life, and symptom scores were recorded. Baseline vs. follow-ups were compared by paired t tests and McNemar's tests. T tests contrasted symptom scores, gastric emptying tests (GET), and mEG measures, while chi-squared tests deciphered comorbidity differences between two groups and univariate and multivariate analyses. There were significantly more patients with diabetes in the Cyc group vs. the NoCyc group. Using a 1 point in symptom outcome, 18 patients did not improve and 19 did improve with tGES. Using univariable analysis, with the cyclic pattern as a predictor, patients exhibiting a cyclic pattern had an odds ratio of 0.22 (95% CI 0.05-0.81, p = 0.054) for achieving an improvement of at least one unit in vomiting at follow-up from baseline. The mucosal electrogastrogram frequency to amplitude ratio (FAR) for the "not Improved" group was 19.6 [3.5, 33.6], whereas, for the "Improved" group, it was 54.3 [25.6, 72.5] with a p-value of 0.049. For multivariate logistic regression, accounting for sex and age squared, patients exhibiting a cyclic pattern had an adjusted odds ratio (OR) of 0.16 (95% CI 0.03-0.81, p = 0.027) for achieving an improvement of at least one unit in vomiting at follow-up from baseline. The two groups had no significant differences in the personal or inherited history of investigated familial patterns. This study shows differences in Gp patients with Cyc vs. NoCyc symptoms in several areas. Larger studies are needed to elicit further differences between the two groups about cycles of symptoms, EGG, findings, familial patterns, and response to mucosal GES.

Gastric myoelectrical associations with autonomic and central nervous system activity during state negative emotionality and perseverative negative thinking: A two-study investigation

BackgroundDistress is known to set off a variety of physiological dysfunctions. There have been previous investigations of central and peripheral (e.g., cardiac) correlates of distress and a burgeoning field examining immunological and inflammatory relationships to distress. However, despite a connection between gastrointestinal symptoms and distress at the clinical level, little research has connected this activity to other biological correlates of distress. Heightened negative emotions and dysregulation of emotions in the form of perseverative negative thinking (PNT, e.g., worry, rumination) are two components that underlie distress. Investigating the effect that these components have on gastric and related biological measures is crucial to better understanding the relationship between distress and health outcomes. We present results from two studies, which examined the impact of experimentally induced negative emotionality and PNT on gastric, autonomic nervous system, central nervous system, and inflammatory processes. MethodIn Study 1 (N = 95), we examined changes in electrogastrogram (EGG), respiratory sinus arrythmia (RSA), and alpha- and beta-band electroencephalogram (EEG) power at baseline and during experimental inductions of fear and sadness in a diverse sample of undergraduate students. In Study 2 (N = 30), we examined changes in EGG, RSA, and EEG at baseline and during worry and rumination inductions. We also collected inflammatory markers post-inductions in Study 2. ResultsIn Study 1, normal gastric activity, vagal tone, and alpha- and beta-band power decreased, whereas EGG cycle length and variability increased during fear and sadness compared to baseline. We also observed significant relationships among EGG, RSA, and EEG during fear and sadness. In Study 2, normal gastric activity and RSA decreased, whereas EGG cycle length and variability increased during rumination compared to baseline. We also observed increases in frontal alpha-band power during worry and rumination compared to baseline. Regarding relationships among EGG, RSA, EEG, and inflammation, greater EGG cycle variability was associated with higher vagal tone during worry; additionally, EGG cycle length and variability during rumination were positively related to CRP and TNF-α inflammation composite scores post-inductions. ConclusionsThese findings offer insight into how negative emotionality and PNT might relate to gastric, ANS, CNS, and inflammatory processes.

A Low-Noise Low-Power 0.001Hz-1kHz Neural Recording System-on-Chip With Sample-Level Duty-Cycling.

Advances in brain-machine interfaces and wearable biomedical sensors for healthcare and human-computer interactions call for precision electrophysiology to resolve a variety of biopotential signals across the body that cover a wide range of frequencies, from the mHz-range electrogastrogram (EGG) to the kHz-range electroneurogram (ENG). Existing integrated wearable solutions for minimally invasive biopotential recordings are limited in detection range and accuracy due to trade-offs in bandwidth, noise, input impedance, and power consumption. This article presents a 16-channel wide-band ultra-low-noise neural recording system-on-chip (SoC) fabricated in 65nm CMOS for chronic use in mobile healthcare settings that spans a bandwidth of 0.001 Hz to 1 kHz through a featured sample-level duty-cycling (SLDC) mode. Each recording channel is implemented by a delta-sigma analog-to-digital converter (ADC) achieving 1.0 μ V rms input-referred noise over 1Hz-1kHz bandwidth with a Noise Efficiency Factor (NEF) of 2.93 in continuous operation mode. In SLDC mode, the power supply is duty-cycled while maintaining consistently low input-referred noise levels at ultra-low frequencies (1.1 μV rms over 0.001Hz-1Hz) and 435 M Ω input impedance. The functionalities of the proposed SoC are validated with two human electrophysiology applications: recording low-amplitude electroencephalogram (EEG) through electrodes fixated on the forehead to monitor brain waves, and ultra-slow-wave electrogastrogram (EGG) through electrodes fixated on the abdomen to monitor digestion.

Gastric dysrhythmias in patients with early systemic sclerosis: a cross-sectional study.

Gastric involvement in patients with early systemic sclerosis (SSc) has not been previously investigated. We aim to evaluate the association of gastric dysrhythmias with gastrointestinal (GI) symptoms and nailfold video capillaroscopy (NVC). Cross-sectional study. Patients with early SSc, completed the UCLA GIT 2.0 questionnaire, performed an NVC, and a surface Electrogastrography (EGG). Descriptive statistics was used for demographic and clinical characteristics and Fisher and Kendall Tau tests were used for association analysis. 75 patients were screened, 30 patients were consecutively enrolled, 29 performed the EGG and 1 patient had a non-interpretable NVC. 29/30 were female with a mean age of 48.7 years (25-72). The mean disease duration from the first non-RP symptom was 22.6 +/-10.8 months and most of the patients had limited disease (76.6%). Total GIT 2.0 score symptoms were moderate-severe in 63% of the participants and 28/29 had an abnormal EGG. Bradygastria was the most common pattern present in 70% of the participants. NVC patterns: 17% early, 34% active, 28% scleroderma-like, 14% non-specific, and 2 patients had a normal NVC. There was no association between severe GI symptoms or NVC patterns and severely abnormal EGG, but the presence of bradygastria was associated with severe impairment in the social functioning area (p 0.018). Gastric dysmotility is common in early SSc and there is a lack of correlation between GI symptoms and NVC scleroderma patterns. EGG is a sensitive, cheap, and non-invasive exam, that may be an alternative to early diagnosis of GI involvement.

Vectorgastrogram: dynamic trajectory and recurrence quantification analysis to assess slow wave vector movement in healthy subjects

Functional gastric disorders entail chronic or recurrent symptoms, high prevalence and a significant financial burden. These disorders do not always involve structural abnormalities and since they cannot be diagnosed by routine procedures, electrogastrography (EGG) has been proposed as a diagnostic alternative. However, the method still has not been transferred to clinical practice due to the difficulty of identifying gastric activity because of the low-frequency interference caused by skin–electrode contact potential in obtaining spatiotemporal information by simple procedures. This work attempted to robustly identify the gastric slow wave (SW) main components by applying multivariate variational mode decomposition (MVMD) to the multichannel EGG. Another aim was to obtain the 2D SW vectorgastrogram VGGSW from 4 electrodes perpendicularly arranged in a T-shape and analyse its dynamic trajectory and recurrence quantification (RQA) to assess slow wave vector movement in healthy subjects. The results revealed that MVMD can reliably identify the gastric SW, with detection rates over 91% in fasting postprandial subjects and a frequency instability of less than 5.3%, statistically increasing its amplitude and frequency after ingestion. The VGGSW dynamic trajectory showed a statistically higher predominance of vertical displacement after ingestion. RQA metrics (recurrence ratio, average length, entropy, and trapping time) showed a postprandial statistical increase, suggesting that gastric SW became more intense and coordinated with a less complex VGGSW and higher periodicity. The results support the VGGSW as a simple technique that can provide relevant information on the “global” spatial pattern of gastric slow wave propagation that could help diagnose gastric pathologies.

Who says you are so sick? An investigation on individual susceptibility to cybersickness triggers using EEG, EGG and ECG.

In this research paper, we conducted a study to investigate the connection between three objective measures: Electrocardio-gram(EGG), Electrogastrogram (EGG), and Electroencephalogram (EEG), and individuals' susceptibility to cybersickness. Our primary objective was to identify which of these factors plays a central role in causing discomfort when experiencing rotations along three different axes: Roll, Pitch, and Yaw. This study involved 35 participants who were tasked with destroying asteroids using their eye gaze while undergoing passive rotations in four separate sessions. The results, when combined with subjective measurements (specifically, Fast motion sickness questionnaire (FMS) and Simulator sickness questionnaire (SSQ) score), demonstrated that EGG measurements were superior in detecting symptoms associated with nausea. As for ECG measurements, our observations did reveal significant changes in Heart Rate Variability (HRV) parameters. However, we caution against relying solely on ECG as a dependable indicator for assessing the extent of cybersickness. Most notably, EEG signals emerged as a crucial resource for discerning individual differences related to these rotational axes. Our findings were significant not only in the context of periodic activities but also underscored the potential of aperiodic activities in detecting the severity of cybersickness and an individual's susceptibility to rotational triggers.

Gastric emptying and myoelectrical activity testing in children with esophageal atresia: A pilot study.

Abnormalities of gastric function in children with esophageal atresia (EA) could potentially contribute to gastrointestinal symptoms and reduced quality of life (QOL). Therefore, we aimed to determine the feasibility and clinical usefulness of gastric function testing in children with EA. The validated PedsQL Gastrointestinal Symptoms Questionnaire (PedsQL-GI) was completed to assess gastrointestinal symptoms and symptom-related QOL. Gastric emptying and gastric myoelectrical activity were studied using 13C-gastric emptying octanoic acid breath test (13C-GEBT) and surface electrogastrography (EGG). Correlations between 13C-GEBT and EGG parameters and PedsQL-GI scores were investigated. Fifteen patients (four males) were included (median age: 6 [3.0-8.5] years). Mean PedsQL-GI scores as reported by the children were comparable to the healthy population. However, parents reported a diminished QOL. Gastric function tests (gastric emptying and/or surface EGG) showed abnormalities in 12 patients (80%). Patients with abnormal slow waves showed abnormal gastric emptying coefficientmore often. There was no significant association between 13C-GEBT nor EGG results and PedsQL-GI scores. 13C-GEBT and EGG can be used to evaluate gastric function in patients with EA. Abnormal gastric function tests were present in 80% of our cohort. However, abnormal gastric function did not significantly correlate with reported gastrointestinal symptom-related QOL.

Exploring the Gut-Brain Connection in Gastroparesis With Autonomic and Gastric Myoelectric Monitoring.

The goal of this study was to identify autonomic and gastric myoelectric biomarkers from throughout the day that differentiate patients with gastroparesis, diabetics without gastroparesis, and healthy controls, while providing insight into etiology. We collected 19 24-hour recordings of electrocardiogram (ECG) and electrogastrogram (EGG) data from healthy controls and patients with diabetic or idiopathic gastroparesis. We used physiologically and statistically rigorous models to extract autonomic and gastric myoelectric information from the ECG and EGG data, respectively. From these, we constructed quantitative indices which differentiated the distinct groups and demonstrated their application in automatic classification paradigms and as quantitative summary scores. We identified several differentiators that separate healthy controls from gastroparetic patient groups, specifically around sleep and meals. We also demonstrated the downstream utility of these differentiators in automatic classification and quantitative scoring paradigms. Even with this small pilot dataset, automated classifiers achieved an accuracy of 79% separating autonomic phenotypes and 65% separating gastrointestinal phenotypes. We also achieved 89% accuracy separating controls from gastroparetic patients in general and 90% accuracy separating diabetics with and without gastroparesis. These differentiators also suggested varying etiologies for different phenotypes. The differentiators we identified were able to successfully distinguish between several autonomic and gastrointestinal (GI) phenotypes using data collected while at-home with non-invasive sensors. Autonomic and gastric myoelectric differentiators, obtained using at-home recording of fully non-invasive signals, can be the first step towards dynamic quantitative markers to track severity, disease progression, and treatment response for combined autonomic and GI phenotypes.

Quantifying the effects of vagus nerve stimulation on gastric myoelectric activity in ferrets using an interpretable machine learning approach.

Vagus nerve stimulation (VNS) is a potential treatment option for gastrointestinal (GI) diseases. The present study aimed to understand the physiological effects of VNS on gastrointestinal (GI) function, which is crucial for developing more effective adaptive closed-loop VNS therapies for GI diseases. Electrogastrography (EGG), which measures gastric electrical activities (GEAs) as a proxy to quantify GI functions, was employed in our investigation. We introduced a recording schema that allowed us to simultaneously induce electrical VNS and record EGG. While this setup created a unique model for studying the effects of VNS on the GI function and provided an excellent testbed for designing advanced neuromodulation therapies, the resulting data was noisy, heterogeneous, and required specialized analysis tools. The current study aimed at formulating a systematic and interpretable approach to quantify the physiological effects of electrical VNS on GEAs in ferrets by using signal processing and machine learning techniques. Our analysis pipeline included pre-processing steps, feature extraction from both time and frequency domains, a voting algorithm for selecting features, and model training and validation. Our results indicated that the electrophysiological changes induced by VNS were optimally characterized by a distinct set of features for each classification scenario. Additionally, our findings demonstrated that the process of feature selection enhanced classification performance and facilitated representation learning.

Electrogastrography in patients with gastric motility disorders.

Electrogastrography (EGG) is a novel diagnostic modality for assessing the gastrointestinal tract (GI) that generates spontaneous electrical activity and monitors gastric motility. The aim of this study was to compare patients with functional dyspepsia (FD) and diabetic gastroparesis (D-GP) with healthy controls (CT) to use established findings on abnormalities of gastric motility based on EGG characteristics. In this study, 50 patients with FD, 50 D-GP patients, and 50 CT subjects were studied to compare EGG with discrete wavelet transform models (DWT) to extract signal characteristics using a variety of different qualitative and quantitative metrics from pre-prandial and postprandial states. As a result, higher statistically significant (p < 0.05*) were found in the DWT models based on power spectral density (PSD) analysis in both states. We also present that the correlations between EGG metrics and the presence of FD, D-GP, and CT symptoms were inconsistent. This paper represents that EGG assessments of FD and D-GP patients differ from healthy controls in terms of abnormalities of gastric motility. Additionally, we demonstrate that diverse datasets showed adequate gastric motility responses to a meal. We anticipate that our method will provide a comprehensive understanding of gastric motility disorders for better treatment and monitoring in both clinical and research settings. In conclusion, we present potential future opportunities for precise gastrointestinal electrophysiological disorders.

Application of electrogastrogram in assessment of gastric motility in acute pancreatitis.

Background: Electrogastrogram (EGG) can reflect gastric motility disorders in many diseases, but its application in acute pancreatitis (AP) has not been studied. Therefore, our study aimed to investigate the value of EGG in assessing the existence of gastric motility disorder in patients with AP and in predicting the severity of AP. Methods: Patients with AP admitted to the First Affiliated Hospital of Nanchang University from June 2020 to December 2020 were enrolled. Five EGG parameters (Percentage of normal gastric slow wave (PNGSW), main frequency, average frequency, percentage of gastric tachycardia (PGT), percentage of gastric bradycardia (PGB)) were collected. The receiver operating characteristic (ROC) curve was constructed to judge the predictive value of EGG parameters to AP severity. Results: The PNGSW in AP patients was significantly lower than that of the control group (p < 0.05), and the PGB was higher in AP patients than that of the control group (p < 0.05). The area under curve (AUC) of the PNGSW and the PGB in diagnosing non-mild acute pancreatitis (N-MAP) were 0.777 (95% CI: 0.676-0.877, p < 0.001) and 0.775 (95% CI: 0.670-0.879, p < 0.001) respectively. After combining with C-reactive protein, the accuracy, sensitivity and specificity of predicting N-MAP were improved. Conclusion: EGG parameters can well reflect the gastric motility disorder of AP patients. The PNGSW and the PGB can be used to predict the occurrence of N-MAP.

Comparison of Gastric Alimetry® body surface gastric mapping versus electrogastrography spectral analysis

Electrogastrography (EGG) non-invasively evaluates gastric motility but is viewed as lacking clinical utility. Gastric Alimetry® is a new diagnostic test that combines high-resolution body surface gastric mapping (BSGM) with validated symptom profiling, with the goal of overcoming EGG’s limitations. This study directly compared EGG and BSGM to define performance differences in spectral analysis. Comparisons between Gastric Alimetry BSGM and EGG were conducted by protocolized retrospective evaluation of 178 subjects [110 controls; 68 nausea and vomiting (NVS) and/or type 1 diabetes (T1D)]. Comparisons followed standard methodologies for each test (pre-processing, post-processing, analysis), with statistical evaluations for group-level differences, symptom correlations, and patient-level classifications. BSGM showed substantially tighter frequency ranges vs EGG in controls. Both tests detected rhythm instability in NVS, but EGG showed opposite frequency effects in T1D. BSGM showed an 8× increase in the number of significant correlations with symptoms. BSGM accuracy for patient-level classification was 0.78 for patients vs controls and 0.96 as compared to blinded consensus panel; EGG accuracy was 0.54 and 0.43. EGG detected group-level differences in patients, but lacked symptom correlations and showed poor accuracy for patient-level classification, explaining EGG’s limited clinical utility. BSGM demonstrated substantial performance improvements across all domains.

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.

Postprandial effect of gastrointestinal hormones and gastric activity in patients with irritable bowel syndrome

Altered gut regulation, including motor and secretory mechanisms, is characteristic of irritable bowel syndrome (IBS). The severity of postprandial symptoms in IBS patients is associated with discomfort and pain; gas-related symptoms such as bloating and abdominal distension; and abnormal colonic motility. The aim of this study was to assess the postprandial response, i.e., gut peptide secretion and gastric myoelectric activity, in patients with constipation-predominant IBS. The study was conducted on 42 IBS patients (14 males, 28 females, mean age 45.1 ± 15.3 years) and 42 healthy participants (16 males, 26 females, mean age 41.1 ± 8.7 years). The study assessed plasma gut peptide levels (gastrin, CCK—Cholecystokinin, VIP—Vasoactive Intestinal Peptide, ghrelin, insulin) and gastric myoelectric activity obtained from electrogastrography (EGG) in the preprandial and postprandial period (meal–oral nutritional supplement 300 kcal/300 ml). Mean preprandial gastrin and insulin levels were significantly elevated in IBS patients compared to the control group (gastrin: 72.27 ± 26.89 vs. 12.27 ± 4.91 pg/ml; p < 0.00001 and insulin: 15.31 ± 12.92 vs. 8.04 ± 3.21 IU/ml; p = 0.0001), while VIP and ghrelin levels were decreased in IBS patients (VIP: 6.69 ± 4.68 vs. 27.26 ± 21.51 ng/ml; p = 0.0001 and ghrelin: 176.01 ± 88.47 vs. 250.24 ± 84.55 pg/ml; p < 0.0001). A nonsignificant change in the CCK level was observed. IBS patients showed significant changes in postprandial hormone levels compared to the preprandial state—specifically, there were increases in gastrin (p = 0.000), CCK (p < 0.0001), VIP (p < 0.0001), ghrelin (p = 0.000) and insulin (p < 0.0001). Patients with IBS showed reduced preprandial and postprandial normogastria (59.8 ± 22.0 vs. 66.3 ± 20.2%) compared to control values (83.19 ± 16.7%; p < 0.0001 vs. 86.1 ± 9.4%; p < 0.0001). In response to the meal, we did not observe an increase in the percentage of normogastria or the average percentage slow-wave coupling (APSWC) in IBS patients. The postprandial to preprandial power ratio (PR) indicates alterations in gastric contractions; in controls, PR = 2.7, whereas in IBS patients, PR = 1.7, which was significantly lower (p = 0.00009). This ratio reflects a decrease in gastric contractility. Disturbances in the postprandial concentration of gut peptides (gastrin, insulin and ghrelin) in plasma may contribute to abnormal gastric function and consequently intestinal motility, which are manifested in the intensification of clinical symptoms, such as visceral hypersensitivity or irregular bowel movements in IBS patients.