Relating gastric scintigraphy and symptoms to motility capsule transit and pressure findings in suspected gastroparesis.

BACKGROUND: Wireless motility capsule (WMC) findings are incompletely defined in suspected gastroparesis. We aimed to characterize regional WMC transit and contractility in relation to scintigraphy, etiology, and symptoms in patients undergoing gastric emptying testing. METHODS: A total of 209 patients with gastroparesis symptoms at NIDDK Gastroparesis Consortium centers underwent gastric scintigraphy and WMCs on separate days to measure regional transit and contractility. Validated questionnaires quantified symptoms. KEY RESULTS: Solid scintigraphy and liquid scintigraphy were delayed in 68.8% and 34.8% of patients; WMC gastric emptying times (GET) were delayed in 40.3% and showed 52.8% agreement with scintigraphy; 15.5% and 33.5% had delayed small bowel (SBTT) and colon transit (CTT) times. Transit was delayed in ≥2 regions in 23.3%. Rapid transit was rarely observed. Diabetics had slower GET but more rapid SBTT versus idiopathics (P ≤ .02). GET delays related to greater scintigraphic retention, slower SBTT, and fewer gastric contractions (P ≤ .04). Overall gastroparesis symptoms and nausea/vomiting, early satiety/fullness, bloating/distention, and upper abdominal pain subscores showed no relation to WMC transit. Upper and lower abdominal pain scores (P ≤ .03) were greater with increased colon contractions. Constipation correlated with slower CTT and higher colon contractions (P = .03). Diarrhea scores were higher with delayed SBTT and CTT (P ≤ .04). CONCLUSIONS & INFERENCES: Wireless motility capsules define gastric emptying delays similar but not identical to scintigraphy that are more severe in diabetics and relate to reduced gastric contractility. Extragastric transit delays occur in >40% with suspected gastroparesis. Gastroparesis symptoms show little association with WMC profiles, although lower symptoms relate to small bowel or colon abnormalities.

Diabetic and idiopathic gastroparesis is associated with loss of CD206-positive macrophages in the gastric antrum.

BACKGROUND: Animal studies have increasingly highlighted the role of macrophages in the development of delayed gastric emptying. However, their role in the pathophysiology of human gastroparesis is unclear. Our aim was to determine changes in macrophages and other cell types in the gastric antrum muscularis propria of patients with diabetic and idiopathic gastroparesis. METHODS: Full thickness gastric antrum biopsies were obtained from patients enrolled in the Gastroparesis Clinical Research Consortium (11 diabetic, 6 idiopathic) and 5 controls. Immunolabeling and quantitative assessment was done for interstitial cells of Cajal (ICC) (Kit), enteric nerves protein gene product 9.5, neuronal nitric oxide synthase, vasoactive intestinal peptide, substance P, tyrosine hydroxylase), overall immune cells (CD45) and anti-inflammatory macrophages (CD206). Gastric emptying was assessed using nuclear medicine scintigraphy and symptom severity using the Gastroparesis Cardinal Symptom Index. RESULTS: Both diabetic and idiopathic gastroparesis patients showed loss of ICC as compared to controls (Mean [standard error of mean]/hpf: diabetic, 2.28 [0.16]; idiopathic, 2.53 [0.47]; controls, 6.05 [0.62]; P=.004). Overall immune cell population (CD45) was unchanged but there was a loss of anti-inflammatory macrophages (CD206) in circular muscle (diabetic, 3.87 [0.32]; idiopathic, 4.16 [0.52]; controls, 6.59 [1.09]; P=.04) and myenteric plexus (diabetic, 3.83 [0.27]; idiopathic, 3.59 [0.68]; controls, 7.46 [0.51]; P=.004). There was correlation between the number of ICC and CD206-positive cells (r=.55, P=.008). Enteric nerves (PGP9.5) were unchanged: diabetic, 33.64 (3.45); idiopathic, 41.26 (6.40); controls, 46.80 (6.04). CONCLUSION: Loss of antral CD206-positive anti-inflammatory macrophages is a key feature in human gastroparesis and it is associates with ICC loss.

Early satiety and postprandial fullness in gastroparesis correlate with gastroparesis severity, gastric emptying, and water load testing.

BACKGROUND: Early satiety (ES) and postprandial fullness (PPF) are often present in gastroparesis, but the importance of these symptoms in gastroparesis has not been well-described. The aims were: (i) Characterize ES and PPF in patients with gastroparesis. (ii) Assess relationships of ES and PPF with etiology of gastroparesis, quality of life, body weight, gastric emptying, and water load testing. METHODS: Gastroparetic patients filled out questionnaires assessing symptoms (PAGI-SYM) and quality of life (PAGI-QOL, SF-36v2). Patients underwent gastric emptying scintigraphy and water load testing. KEY RESULTS: 198 patients with gastroparesis (134 IG, 64 DG) were evaluated. Early satiety was severe or very severe in 50% of patients. Postprandial fullness was severe or very severe in 60% of patients. Severity scores for ES and PPF were similar between idiopathic and diabetic gastroparesis. Increasing severity of ES and PPF were associated with other gastroparesis symptoms including nausea/vomiting, satiety/early fullness, bloating, and upper abdominal pain and GERD subscores. Increasing severity of ES and PPF were associated with increasing gastroparesis severity, decreased BMI, decreased quality of life from PAGI-QOL and SF-36 physical health. Increasing severity of ES and PPF were associated with increasing gastric retention of a solid meal and decreased volume during water load test. CONCLUSIONS & INFERENCES: Early satiety and PPF are commonly severe symptoms in both diabetic and idiopathic gastroparesis. Early satiety and PPF severity are associated with other gastroparesis symptom severities, body weight, quality of life, gastric emptying, and water load testing. Thus, ES and PPF are important symptoms characterizing gastroparesis. ClinicalTrials.gov number: NCT NCT01696747.

Nausea and vomiting in gastroparesis: similarities and differences in idiopathic and diabetic gastroparesis.

BACKGROUND: Nausea and vomiting are classic symptoms of gastroparesis. It remains unclear if characteristics of nausea and vomiting are similar in different etiologies of gastroparesis. The aims of this article were as follows: to describe characteristics of nausea and vomiting in patients with gastroparesis and to determine if there are differences in nausea and vomiting in diabetic (DG) and idiopathic gastroparesis (IG). METHODS: Gastroparetic patients enrolling in the NIDDK Gastroparesis Registry underwent assessment with history and questionnaires assessing symptoms, quality of life, and a questionnaire characterizing nausea and vomiting. KEY RESULTS: Of 159 gastroparesis patients (107 IG, 52 DG), 96% experienced nausea, whereas 65% experienced vomiting. Nausea was predominant symptom in 28% and vomiting was predominant in 4%. Nausea was severe or very severe in 41%. PAGI-SYM nausea/vomiting subscore was greater with increased vomiting severity, but not nausea severity in DG than IG. Nausea was related to meals in 71%; lasting most of the day in 41%. Increasing nausea severity was related to decreased quality of life. Nausea often preceded vomiting in 82% of patients and vomiting often relieved nausea in 30%. Vomiting was more common in DG (81%) compared to IG (57%; p = 0.004). Diabetic patients more often had vomiting in the morning before eating, during the night, and when not eating. CONCLUSIONS & INFERENCES: Nausea is present in essentially all patients with gastroparesis irrespective of cause and associated with decreased quality of life. In contrast, vomiting was more prevalent, more severe, and occurred more often in DG than IG. Thus, characteristics of vomiting differ in IG vs DG.

Baseline features and differences in 48 week clinical outcomes in patients with gastroparesis and type 1 vs type 2 diabetes.

BACKGROUND: In studies of diabetic gastroparesis, patients with type 1 and type 2 diabetes mellitus (T1DM, T2DM) are often combined for analyses. We compared gastroparesis severity, healthcare utilization, psychological function, and quality of life in T1DM vs T2DM gastroparesis patients. METHODS: Questionnaire, laboratory, and scintigraphy data from patients with gastroparesis and T1DM and T2DM from seven centers of the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium Registry were compared at enrollment and after 48 weeks. Multiple regression models assessed baseline and follow-up differences between diabetes subtypes. KEY RESULTS: At baseline, T1DM patients (N = 78) had slower gastric emptying, more hospitalizations, more gastric stimulator implantations, higher hemoglobin A1c (HbA1c), and more anxiety vs T2DM patients (N = 59). Independent discriminators of patients with T1DM vs T2DM included worse gastroesophageal reflux disease, less bloating, more peripheral neuropathy, and fewer comorbidities (p ≤ 0.05). On follow-up, gastrointestinal (GI) symptom scores decreased only in T2DM (p < 0.05), but not in T1DM patients who reported greater prokinetic, proton pump inhibitor, anxiolytic, and gastric stimulator usage over 48 weeks (p ≤ 0.03). Gastrointestinal symptoms at baseline and 48 weeks with both subtypes were not associated with HbA1c, peripheral neuropathy, psychological factors, or quality of life. CONCLUSIONS & INFERENCES: Baseline symptoms were similar in T1DM and T2DM patients, even though T1DM patients had worse gastric emptying delays and higher HbA1c suggesting other factors mediate symptom severity. Symptom scores at 48 weeks decreased in T2DM, but not T1DM patients, despite increased medical and surgical treatment utilization by T1DM patients. Defining causes of different outcomes in diabetic gastroparesis warrants further investigation.

Association of low numbers of CD206-positive cells with loss of ICC in the gastric body of patients with diabetic gastroparesis.

BACKGROUND: There is increasing evidence for specific cellular changes in the stomach of patients with diabetic (DG) and idiopathic (IG) gastroparesis. The most significant findings are loss of interstitial cells of Cajal (ICC), neuronal abnormalities, and an immune cellular infiltrate. Studies done in diabetic mice have shown a cytoprotective effect of CD206+ M2 macrophages. To quantify overall immune cellular infiltrate, identify macrophage populations, and quantify CD206+ and iNOS+ cells. To investigate associations between cellular phenotypes and ICC. METHODS: Full thickness gastric body biopsies were obtained from non-diabetic controls (C), diabetic controls (DC), DG, and IG patients. Sections were labeled for CD45, CD206, Kit, iNOS, and putative human macrophage markers (HAM56, CD68, and EMR1). Immunoreactive cells were quantified from the circular muscle layer. KEY RESULTS: Significantly fewer ICC were detected in DG and IG tissues, but there were no differences in the numbers of cells immunoreactive for other markers between patient groups. There was a significant correlation between the number of CD206+ cells and ICC in DG and DC patients, but not in C and IG and a significant correlation between iNOS+ cells and ICC in the DC group, but not the other groups. CD68 and HAM56 reliably labeled the same cell populations, but EMR1 labeled other cell types. CONCLUSIONS & INFERENCES: Depletion of ICC and correlation with changes in CD206+ cell numbers in DC and DG patients suggests that in humans, like mice, CD206+ macrophages may play a cytoprotective role in diabetes. These findings may lead to novel therapeutic options, targeting alternatively activated macrophages.

Factors related to abdominal pain in gastroparesis: contrast to patients with predominant nausea and vomiting.

BACKGROUND: Factors associated with abdominal pain in gastroparesis are incompletely evaluated and comparisons of pain vs other symptoms are limited. This study related pain to clinical factors in gastroparesis and contrasted pain/discomfort- with nausea/vomiting-predominant disease. METHODS: Clinical and scintigraphy data were compared in 393 patients from seven centers of the NIDDK Gastroparesis Clinical Research Consortium with moderate-severe (Patient Assessment of Upper Gastrointestinal Disorders Symptoms [PAGI-SYM] score ≥ 3) vs none-mild (PAGI-SYM < 3) upper abdominal pain and predominant pain/discomfort vs nausea/vomiting. KEY RESULTS: Upper abdominal pain was moderate-severe in 261 (66%). Pain/discomfort was predominant in 81 (21%); nausea/vomiting was predominant in 172 (44%). Moderate-severe pain was more prevalent with idiopathic gastroparesis and with lack of infectious prodrome (P ≤ 0.05) and correlated with scores for nausea/vomiting, bloating, lower abdominal pain/discomfort, bowel disturbances, and opiate and antiemetic use (P < 0.05), but not gastric emptying or diabetic neuropathy or control. Gastroparesis severity, quality of life, and depression and anxiety were worse with moderate-severe pain (P ≤ 0.008). Factors associated with moderate-severe pain were similar in diabetic and idiopathic gastroparesis. Compared to predominant nausea/vomiting, predominant pain/discomfort was associated with impaired quality of life, greater opiate, and less antiemetic use (P < 0.01), but similar severity and gastric retention. CONCLUSIONS & INFERENCES: Moderate-severe abdominal pain is prevalent in gastroparesis, impairs quality of life, and is associated with idiopathic etiology, lack of infectious prodrome, and opiate use. Pain is predominant in one fifth of gastroparetics. Predominant pain has at least as great an impact on disease severity and quality of life as predominant nausea/vomiting.

Clinical-histological associations in gastroparesis: results from the Gastroparesis Clinical Research Consortium.

BACKGROUND: Cellular changes associated with diabetic (DG) and idiopathic gastroparesis (IG) have recently been described from patients enrolled in the Gastroparesis Clinical Research Consortium. The association of these cellular changes with gastroparesis symptoms and gastric emptying is unknown. The aim of this study was to relate cellular changes to symptoms and gastric emptying in patients with gastroparesis. METHODS: Earlier, using full thickness gastric body biopsies from 20 DG, 20 IG, and 20 matched controls, we found decreased interstitial cells of Cajal (ICC) and enteric nerves and an increase in immune cells in both DG and IG. Here, demographic, symptoms [gastroparesis cardinal symptom index score (GCSI)], and gastric emptying were related to cellular alterations using Pearson's correlation coefficients. KEY RESULTS: Interstitial cells of Cajal counts inversely correlated with 4 h gastric retention in DG but not in IG (r = -0.6, P = 0.008, DG, r = 0.2, P = 0.4, IG). There was also a significant correlation between loss of ICC and enteric nerves in DG but not in IG (r = 0.5, P = 0.03 for DG, r = 0.3, P = 0.16, IG). Idiopathic gastroparesis with a myenteric immune infiltrate scored higher on the average GCSI (3.6 ± 0.7 vs 2.7 ± 0.9, P = 0.05) and nausea score (3.8 ± 0.9 vs 2.6 ± 1.0, P = 0.02) as compared to those without an infiltrate. CONCLUSIONS & INFERENCES: In DG, loss of ICC is associated with delayed gastric emptying. Interstitial cells of Cajal or enteric nerve loss did not correlate with symptom severity. Overall clinical severity and nausea in IG is associated with a myenteric immune infiltrate. Thus, full thickness gastric biopsies can help define specific cellular abnormalities in gastroparesis, some of which are associated with physiological and clinical characteristics of gastroparesis.

Bitter taster status predicts susceptibility to vection-induced motion sickness and nausea.

BACKGROUND: Sensitivity to bitter taste and susceptibility to nausea are both protective mechanisms that guard against toxin ingestion, and both these traits vary within and between populations. Thus, we postulated that they may have co-evolved, such that they are associated. METHODS: Bitter taster status was determined in 40 subjects (13 men, 27 women) by measuring the differential perceived taste intensity between salt and n-propylthiouracil using a labeled magnitude scale; susceptibility to vection-induced motion sickness and nausea was assessed using an optokinetic drum, a validated multi-symptom scoring scale, and electrogastrography. KEY RESULTS: Taster status distribution was 25% non-tasters (NT), 40% tasters (T), and 35% supertasters (ST). Gender had no impact on this distribution, but females had a higher mean maximum symptom score than males (12.4 ± 1.4 vs 7.3 ± 2.0). Non-tasters displayed a faster and larger increase in mean symptom scores, had a higher percentage of subjects with high maximum symptom scores, and had a higher mean maximum score than T or ST, (14.8 ± 2.6 vs 7.1 ± 1.8, vs 9.8 ± 2.0). Taster status did not affect the gastric myoelectric frequency response to vection. CONCLUSIONS & INFERENCES: Non-tasters are more susceptible to vection-induced motion sickness and nausea than T or ST, suggesting these two traits may have co-evolved in a reciprocal manner: in environments where the NT trait conferred an evolutionary advantage by enabling intake of fruits and vegetables containing bitter, yet beneficial, phytonutrients, increased nausea susceptibility may have arisen to maintain protection against ingested toxins.

The electrifying stomach.

The stomach is electrified and subject to eurhythmic and dysrhythmic electrical events - much like the heart. The normal human slow wave ranges from 2.5 to 3.75 cycles per min (cpm), tachygastrias range from 3.75 cpm to 10.0 cpm and bradygastrias from .5 to 2.5 cpm, the gastric dysrhythmias of men and women. In this issue of Neurogastroenterology & Motility, O'Grady, et al. describe the gastric dysrhythmias of pigs in electrocardiology terms. Printed circuit boards (PCB) with multi-electrode arrays (160-192 electrodes) were attached to the stomach serosa. Gastric dysrhythmias occurred in eight of the 16 anesthetized pigs and were analysed by manually and by computer. The patterns of dysrhythmias were reminiscent of cardiac dysrhythmias: conduction blocks, ectopic foci, re-entrant wave fronts, premature and aberrant slow waves and regular and irregular tachygastrias. The authors suggest gastric dysrhythmias recorded in pigs may be relevant to human gastric dysrhythmias and electricity-based therapies. The categories of porcine gastric dysrhythmias may help to understand the spectrum of gastric dysrhythmias of men and women recorded over the past 25 years. Analogies between gastric and cardiac neuromuscular disorders are explored because Neurogastroenterology is evolving as a clinical and therapeutic field utilizing knowledge of gastric rhythmicity and electro-contractile events. Interstitial cells of Cajal are the pacemaker cells of the stomach and loss of cells or faulty circuitry appear to be key pathways to gastric dysrhythmias. Gastric electrophysiology (EP) labs, human and animal, are needed to test hypotheses and advance understanding of human gastric dysrhythmias and upper GI symptoms.

Motility of the antroduodenum in healthy and gastroparetics characterized by wireless motility capsule.

BACKGROUND: The wireless motility capsule (WMC) measures intraluminal pH and pressure, and records transit time and contractile activity throughout the gastrointestinal tract. Our hypothesis is that WMC can differentiate antroduodenal pressure profiles between healthy people and patients with upper gut motility dysfunctions. This study aims to analyze differences in the phasic pressure profiles of the stomach and small intestine in healthy and gastroparetic subjects. METHODS: Data from 71 healthy and 42 gastroparetic subjects were analyzed. The number of contractions (Ct), area under the pressure curve and motility index (MI = Ln (Ct *sum amplitudes +1)) were analyzed for 60 min before gastric emptying of the capsule (GET), (gastric window) and after GET (small bowel window) and results between groups were compared with the Wilcoxon rank sum test. KEY RESULTS: Significant differences were observed between healthy and gastroparetic subjects for Ct and MI (P < 0.05). Median values of the motility parameters in gastric window were Ct = 72, MI = 11.83 for healthy and Ct = 47, MI = 11.12 for gastroparetics. In the small bowel, median values were Ct = 144.5, MI = 12.78 for healthy and Ct = 93, MI = 12.12 for gastroparetics. Diabetic subjects with gastroparesis showed significantly lower Ct and MI compared with healthy subjects in both gastric and small bowel windows while idiopathic gastroparetic subjects did not show significant differences. CONCLUSIONS & INFERENCES: The WMC is able to differentiate between healthy and gastroparetic subjects based on gastric and small bowel motility profiles.

The assessment of regional gut transit times in healthy controls and patients with gastroparesis using wireless motility technology.

BACKGROUND: Wireless pH and pressure motility capsule (wireless motility capsule) technology provides a method to assess regional gastrointestinal transit times. AIMS: To analyse data from a multi-centre study of gastroparetic patients and healthy controls and to compare regional transit times measured by wireless motility capsule in healthy controls and gastroparetics (GP). METHODS: A total of 66 healthy controls and 34 patients with GP (15 diabetic and 19 idiopathic) swallowed wireless motility capsule together with standardized meal (255 kcal). Gastric emptying time (GET), small bowel transit time (SBTT), colon transit time (CTT) and whole gut transit time (WGTT) were calculated using the wireless motility capsule. RESULTS: Gastric emptying time, CTT and WGTT but not SBTT were significantly longer in GP than in controls. Eighteen percent of gastroparetic patients had delayed WGTT. Both diabetic and idiopathic aetiologies of gastroparetics had significantly slower WGTT (P < 0.0001) in addition to significantly slower GET than healthy controls. Diabetic gastroparetics additionally had significantly slower CTT than healthy controls (P = 0.0054). CONCLUSIONS: In addition to assessing gastric emptying, regional transit times can be measured using wireless motility capsule. The prolongation of CTT in gastroparetic patients indicates that dysmotility beyond the stomach in GP is present, and it could be contributing to symptom presentation.

Gastroparesis and functional dyspepsia: excerpts from the AGA/ANMS meeting.

BACKGROUND: Despite the relatively high prevalence of gastroparesis and functional dyspepsia, the aetiology and pathophysiology of these disorders remain incompletely understood. Similarly, the diagnostic and treatment options for these two disorders are relatively limited despite recent advances in our understanding of both disorders. PURPOSE: This manuscript reviews the advances in the understanding of the epidemiology, pathophysiology, diagnosis, and treatment of gastroparesis and functional dyspepsia as discussed at a recent conference sponsored by the American Gastroenterological Association (AGA) and the American Neurogastroenterology and Motility Society (ANMS). Particular focus is placed on discussing unmet needs and areas for future research.

Comparison of gastric emptying of a nondigestible capsule to a radio-labelled meal in healthy and gastroparetic subjects.

BACKGROUND: Gastric emptying scintigraphy (GES) using a radio-labelled meal is used to measure gastric emptying. A nondigestible capsule, SmartPill, records luminal pH, temperature, and pressure during gastrointestinal transit providing a measure of gastric emptying time (GET). AIMS: To compare gastric emptying time and GES by assessing their correlation, and to compare GET and GES for discriminating healthy subjects from gastroparetics. METHODS: Eighty-seven healthy subjects and 61 gastroparetics enrolled with simultaneous SmartPill and GES. Fasted subjects were ingested capsule and [(99m)Tc]-SC radio-labelled meal. Images were obtained every 30 min for 6 h. Gastric emptying time and percentage of meal remaining at 2/4 h were determined for each subject. The sensitivity/specificity and receiver operating characteristic analysis of each measure were determined for each subject. RESULTS: Correlation between GET and GES-4 h was 0.73 and GES-2 h was 0.63. The diagnostic accuracy from the receiver operating characteristic curve between gastroparetics and healthy subjects was GET = 0.83, GES-4 h = 0.82 and GES-2 h = 0.79. The 300-min cut-off time for GET gives sensitivity of 0.65 and specificity of 0.87 for diagnosis of gastroparesis. The corresponding sensitivity/specificity for 2 and 4 h standard GES measures were 0.34/0.93 and 0.44/0.93, respectively. CONCLUSION: SmartPill GET correlates with GES and discriminates between healthy and gastroparetic subjects offering a nonradioactive, standardized, ambulatory alternative to scintigraphy.

Electrogastrographic biofeedback: a technique for enhancing normal gastric activity.

Biofeedback has been used effectively for approximately 40 years as a technique to help individuals learn to control muscle activity, brain waves, certain autonomic nervous system responses such as heart rate and blood pressure, and, more recently, constipation and fecal and urinary incontinence. In the present study, biofeedback of electrogastrographic (EGG) activity was used to determine the extent to which healthy subjects could increase normal 3 cpm gastric myoelectric activity. Thirteen experimental participants were provided with biofeedback of their EGG activity on a computer screen, and instructed to try to make their own EGG signal match a simulated 3 cpm signal that was also present on the screen. Subjects were told to relax using various forms of imagery, and to heighten their awareness of their stomach activity. Thirteen control participants did not receive any biofeedback but were otherwise given the same instructions. Both groups showed an increase in 3 cpm activity while relaxing. However, over four trials separated by 2-7 days, experimental participants showed an increased percentage of 3 cpm activity during biofeedback sessions, while control participants showed a decrease in 3 cpm activity during the corresponding sessions. In conclusion, we have demonstrated that healthy subjects can increase their normal gastric 3 cpm activity with the use of EGG biofeedback.

Gastroparesis and neuromuscular disorders of the stomach.

Gastroparesis is the most severe form of gastric neuromuscular dysfunction along a continuum that encompasses gastric visceral hypersensitivity, gastric dysrhythmias, and pylorospasm. Gastroparesis may present with vague dyspepsia symptoms or with vomiting of undigested food and weight loss. A careful history and physical examination may suggest the diagnosis of gastroparesis, but symptoms associated with gastric neuromuscular disorders are non-specific. Gastroparesis in patients with diabetes, particularly type 2 diabetes, is more common than appreciated. If gastroparesis is confirmed, then reversible causes such as mechanical obstruction of stomach and chronic mesenteric ischemia must be excluded. ''Idiopathic'' gastroparesis may follow viral infections or be due to degenerative processes that affect gastric enteric neurons, smooth muscle, and/or interstitial cells of Cajal. An approach to the diagnosis and treatment of gastroparesis and gastric neuromuscular disorders is reviewed including dietary counselling and new medical devices.

Electrogastrography: physiological basis and clinical application in diabetic gastropathy.

Electrogastrography is the recording and measurement of gastric myoelectrical activity from electrodes placed on the surface of the epigastrium. Normal electrogastrograms (EGGs) reflect 3 cycles per min (cpm) gastric myoelectrical activity produced by specialized pacemaker cells, the interstitial cells of Cajal, located in the muscular wall of the gastric corpus and antrum. Gastric dysrhythmias (tachygastrias and bradygastrias) are disturbances of the normal gastric pacesetter potentials and are associated with symptoms of nausea, epigastric fullness, and bloating and with hyperglycemia and delayed gastric emptying. In diabetic gastropathy, the normal 3-cpm electrical rhythm is replaced with bradygastrias, tachygastrias, and mixed or nonspecific dysrhythmias. Diagnosis of gastric dysrhythmias identifies an objective neuromuscular abnormality in diabetic patients with upper gastrointestinal (GI) symptoms. Correction of gastric dysrhythmias decreases upper GI symptoms and may improve gastric emptying all of which may enhance glucose control. The EGG diagnosis of gastric dysrhythmias provides new insights into gastric neuromuscular abnormalities and guides therapies to improve upper GI symptoms in patients with diabetes mellitus.

The stomach's response to unappetizing food: cephalic-vagal effects on gastric myoelectric activity.

The aim of this investigation was to determine the effects of sham feeding food that was perceived as unappetizing on the cephalic-vagal reflex as measured by changes in gastric myoelectric activity. Thirty-eight healthy human participants experienced one of two conditions: (i) an appetizing sham feeding condition in which participants chewed and expectorated two cooked frankfurters, and (ii) an unappetizing sham-feeding condition in which participants chewed and expectorated two cold tofu frankfurters. All participants were asked to chew each mouth-full of food 6-7 times and to be very careful not to swallow any of the food. Electrogastrograms (EGGs) were recorded for 10 min prior to, during, and for 15 min after sham feeding. A questionnaire was given to each participant after the procedure as a manipulation check and to assess food palatability. Results from the questionnaire showed, as expected, that the cooked frankfurters were significantly more appetizing than the cold tofu frankfurters (P < 0.01). In the group sham fed appetizing food, 3 cycles per minute (cpm) power increased during sham feeding, but the change was not significant; however, 3 cpm power decreased in the group sham fed unappetizing food. This difference was significant (P < 0.05). In conclusion, we have demonstrated that the cephalic-vagal reflex, as measured by power in the 3 cpm frequency region of the EGG, is sensitive to the subjective palatability of the food.

Reproducibility of gastric myoelectrical activity and the water load test in patients with dysmotility-like dyspepsia symptoms and in control subjects.

Gastric dysrhythmias and normal gastric myoelectrical activity have been recorded in patients with functional dyspepsia. The aim of this study was to determine the reproducibility of gastric myoelectrical patterns and responses to a water load in patients with dysmotility-like functional dyspepsia and healthy control subjects. We studied 24 patients with dysmotility-like functional dyspepsia and 24 age-matched control subjects. Gastric myoelectrical activity was assessed using cutaneous electrodes to record electrogastrograms (EGGs) before and after the subjects ingested water until full. The EGGs with water load tests were repeated 1 week apart. The patients ingested significantly smaller volumes of water at both week 1 and 2 (358 +/- 26 mL and 349 +/- 30 mL) compared to control subjects (557 +/- 35 mL and 560 +/- 27 mL, p < 0.01). Gastric dysrhythmias were found in 4 of 24 (16.7%) control subjects at each visit and in 14 (58%) and 12 (50%) of the dyspeptic patients at week 1 and 2, respectively. Of 14 patients, 2 (14.3%) had gastric dysrhythmias at week 1 but had normal gastric rhythms at week 2. Thus, reproducibility was 100% in the control subjects and 91.7% in the patients. In conclusion, some variability in EGG pattern occurred, but gastric myoelectrical activity and responses to the water load test were generally consistent and reproducible in patients with dysmotility-like functional dyspepsia and in healthy control subjects.

Assessment of gastric emptying using a low fat meal: establishment of international control values.

OBJECTIVE: The diagnosis of gastroparesis implies delayed gastric emptying. The diagnostic gold standard is scintigraphy, but techniques and measured endpoints vary widely among institutions. In this study, a simplified scintigraphic measurement of gastric emptying was compared to conventional gastric scintigraphic techniques and normal gastric emptying values defined in healthy subjects. METHODS: In 123 volunteers (aged 19-73 yr, 60 women and 63 men) from 11 centers, scintigraphy was used to assess gastric emptying of a 99Tc-labeled low fat meal (egg substitute) and percent intragastric residual contents 60, 120, and 240 min after completion of the meal. In 42 subjects, additional measurements were taken every 10 min for 1 h. In 20 subjects, gastric emptying of a 99Tc-labeled liver meal was compared with that of the 99Tc-labeled low fat meal. RESULTS: Median values (95th percentile) for percent gastric retention at 60, 120, and 240 min were 69% (90%), 24% (60%) and 1.2% (10%) respectively. A power exponential model yielded similar emptying curves and estimated T50 when using images only taken at 1, 2 and 4 h, or with imaging taken every 10 min. Gastric emptying was initially more rapid in men but was comparable in men and women at 4 h; it was faster in older subjects (p < 0.05) but was independent of body mass index. CONCLUSIONS: This multicenter study provides gastric emptying values in healthy subjects based on data obtained using a large sample size and consistent meal and methodology. Gastric retention of >10% at 4 h is indicative of delayed emptying, a value comparable to those provided by more intensive scanning approaches. Gastric emptying of a low fat meal is initially faster in men but is comparable in women at 4 h; it is also faster in older individuals but is independent of body mass.