Multicenter, Phase 1, Open Prospective Trial of Gastric Electrical Stimulation for the Treatment of Obesity: First-in-Human Results with a Novel Implantable System

Background and Aims

To assess safety of the Exilis™ gastric electrical stimulation (GES) system and to investigate whether the settings can be adjusted for comfortable chronic use in subjects with morbid obesity. Gastric emptying and motility and meal intake were evaluated.

Method

In a multicenter, phase 1, open prospective cohort study, 20 morbidly obese subjects (17 female, mean BMI of 40.8 ± 0.7 kg/m²) were implanted with the Exilis™ system. Amplitude of the Exilis™ system was individually set during titration visits. Subjects underwent two blinded baseline test days (GES ON vs. OFF), after which long-term, monthly follow-up continued for up to 52 weeks.

Results

The procedure was safe, and electrical stimulation was well tolerated and comfortable in all subjects. No significant differences in gastric emptying halftime (203 ± 16 vs. 212 ± 14 min, p > 0.05), food intake (713 ± 68 vs. 799 ± 69 kcal, p > 0.05), insulin AUC (2448 ± 347 vs. 2186 ± 204, p > 0.05), and glucose AUC (41 ± 2 vs.41 ± 2, p > 0.05) were found between GES ON and OFF. At week 4, 13, and 26, a significant (p < 0.01) reduction in weight loss was observed but not at week 52. At this time point, the mean excess weight loss (EWL) was 14.2 ± 4.5%.

Conclusion

Gastric electrical stimulation with the Exilis™ system can be considered as safe. No significant effect on food intake, gastric emptying, or gastric motility was observed. The reduction in weight loss with Exilis™ GES was significant but short lasting. Further electrophysiological research is needed to gain more insight in optimal stimulation parameters and lead localization.

Intravenous immunoglobulin in drug and device refractory patients with the symptoms of gastroparesis-an open-label study

BACKGROUND

Gastroparesis is a complex clinical entity; many aspects of which remain unknown. Although most patients have idiopathic, diabetic, or postsurgical gastroparesis, many are thought to have measurable neuromuscular abnormalities. Immunotherapy has recently been utilized to treat suspected autoimmune gastrointestinal dysmotility.

METHODS

Fourteen patients with symptoms of gastroparesis (Gp) who were refractory to drug/device were selected from 443 Gp patients from 2013 to 2015 who were treated at the University of Louisville motility center. All patients underwent a structural and psychiatric evaluation along with detailed psychological and behavioral examination to rule out eating disorders. We performed detailed neuromuscular evaluation and all 14 patients received at least 12 weeks of intravenous immunoglobulin (400 mg/kg infusion weekly). Response was defined subjectively (symptomatic improvement) using standardized IDIOM score system.

KEY RESULTS

All 14 patients had serological evidence and/or tissue evidence of immunological abnormality. Post-IVIG therapy, there was a significant improvement in symptoms scores for nausea, vomiting, early satiety, and abdominal pain.

CONCLUSIONS AND INFERENCES

Although limited by the absence of placebo group, the data illustrate the role of autoimmunity and neuromuscular evaluation in patients with gastroparesis and support the utility of a diagnostic trial of immunotherapy in an effort to improve therapeutic outcomes for such patients.

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.

Relationships between gastric slow wave frequency, velocity, and extracellular amplitude studied by a joint experimental-theoretical approach

BACKGROUND

Gastric slow wave dysrhythmias are accompanied by deviations in frequency, velocity, and extracellular amplitude, but the inherent association between these parameters in normal activity still requires clarification. This study quantified these associations using a joint experimental-theoretical approach.

METHODS

Gastric pacing was conducted in pigs with simultaneous high-resolution slow wave mapping (32-256 electrodes; 4-7.6 mm spacing). Relationships between period, velocity, and amplitude were quantified and correlated for each wavefront. Human data from two existing mapping control cohorts were analyzed to extract and correlate these same parameters. A validated biophysically based ICC model was also applied in silico to quantify velocity-period relationships during entrainment simulations and velocity-amplitude relationships from membrane potential equations.

KEY RESULTS

Porcine pacing studies identified positive correlations for velocity-period (0.13 mm s^-1 per 1 s, r² =.63, P<.001) and amplitude-velocity (74 μV per 1 mm s^-1 , r² =.21, P=.002). In humans, positive correlations were also quantified for velocity-period (corpus: 0.11 mm s^-1 per 1 s, r² =.16, P<.001; antrum: 0.23 mm s^-1 per 1 s, r² =.55; P<.001), and amplitude-velocity (94 μV per 1 mm s^-1 , r² =.56; P<.001). Entrainment simulations matched the experimental velocity-period relationships and demonstrated dependence on the slow wave recovery phase. Simulated membrane potential relationships were close to these experimental results (100 μV per 1 mm s^-1 ).

CONCLUSIONS AND INFERENCES

These data quantify the relationships between slow wave frequency, velocity, and extracellular amplitude. The results from both human and porcine studies were in keeping with biophysical models, demonstrating concordance with ICC biophysics. These relationships are important in the regulation of gastric motility and will help to guide interpretations of dysrhythmias.

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.

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.

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.

Gastric dysmotility and low serum vitamin D levels in patients with gastroparesis

Nutritional abnormalities are common in patients with gastroparesis (Gp), a disorder that may affect gastric motility and may delay emptying. The aim of this work was to identify relationships between serum nutrition markers including 25-OH vitamin D and gastric motility measures in Gp patients. We enrolled 59 consecutive gastric motility clinic patients (48 females, 11 males; mean age 44 years; 42 idiopathic; 17 diabetes mellitus) with Gp symptoms. The 25-OH vitamin D levels, for most patients slightly above the lower limit of normal (96.98 nmol/l ± 60.99), were lowest in diabetic range (DM) (75.68 nmol/l ± 34.22) vs. idiopathic (ID) (105.03 nmol/l ± 67.08) gastroparesis patients. First hour GET: one unit increase in 25-OH vitamin D level was associated 0.11% improvement (95% CI -0.22, 0.01 p=0.056) in gastric motility in all patients; this association, although marked in ID Gp patients, (-0.13, CI -0.25, -0.01 p=0.034), was not seen in DM Gp, (0.2, CI -0.45, 0.87, p=0.525). Fourth hour GET: Every unit increase of 25-OH vitamin D was associated with significant improvement in all patients, ( 0.11% CI -0.23, 0.01, p=0.053), and some weak improvement in ID group, (0.11% -0.24, 0.01, p=0.076) and absent in patients with DM (0.03, CI -0.66, 0.72, p=0.932). It is concluded that 25-OH vitamin D levels may influence gastric emptying. Underlying mechanisms for this observation might include the impact of 25-OH vitamin D on the health of the enteric nervous system. 25-OH vitamin D contributions to enteric nerve functions should be explored, particularly where autonomic nervous system comorbidities exist.

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.

Cyclic vomiting syndrome in adults

Cyclic vomiting syndrome (CVS) was initially described in children but can occur in all age groups. Cyclic vomiting syndrome is increasingly recognized in adults. However, the lack of awareness of CVS in adults has led to small numbers of diagnosed patients and a paucity of published data on the causes, diagnosis and management of CVS in adults. This article is a state-of-knowledge overview on CVS in adults and is intended to provide a framework for management and further investigations into CVS in adults.

An energy algorithm improves symptoms in some patients with gastroparesis and treated with gastric electrical stimulation

Gastric electrical stimulation (GES) is effective to improve symptoms of nausea and vomiting in most patients, but very little is known about the effect of varying stimulation parameters. We analysed stimulation parameters in a pilot study of 22 patients (12 idiopathic, four diabetic and four postsurgical) with drug-refractory gastroparesis who did not respond optimally to initial settings. Patients underwent high-frequency/low energy GES using identical initial stimulation parameters: 5 mA of current, 330 micros pulse width, 14 Hz for 0.1 s on and 5.0 s off. Due to lack on optimal response, 22 patients underwent alteration of an algorithm using stimulation parameters. At follow-up (mean of 4.3 years) a dose-response relationship for charge, power and energy were compared with baseline for the whole group and for each diagnostic subgroup by anova data are reported as mean +/- SE. Based on the mean of individual dose-response curves, differences in data are charge, current per pulse and energy per pulse were noted for the whole group at follow up vs baseline. The subgroup of patients with postsurgical gastroparesis required the most energy using the algorithm. In conclusion, an algorithmic approach to identify optimal stimulation parameters in GES for individual patients is associated with symptom improvement. Also, certain subgroups appear to have different energy parameters. Based on this preliminary data, the use of an algorithm for some patients with GES is feasible and may have potential for clinical application. A randomized-controlled trial of different stimulation parameters for GES seems warranted.

Treatment of gastroparesis: a multidisciplinary clinical review

This clinical review on the treatment of patients with gastroparesis is a consensus document developed by the American Motility Society Task Force on Gastroparesis. It is a multidisciplinary effort with input from gastroenterologists and other specialists who are involved in the care of patients with gastroparesis. To provide practical guidelines for treatment, this document covers results of published research studies in the literature and areas developed by consensus agreement where clinical research trials remain lacking in the field of gastroparesis.

Postinfectious gastroparesis related to autonomic failure: a case report

BACKGROUND AND AIM

Severe dysautonomia may be secondary to viral infections, resulting in impaired autoimmune, cardiovascular, urinary and digestive dysfunction. Herein, we present a case of a 31-year-old white female patient who had severe gastroparesis related to autonomic failure following an episode of acute gastroenteritis. This seems to be the first report providing thorough assessment of the enteric and autonomic nervous system by analysis of full-thickness small intestinal biopsies, cardiovagal testing and autopsy.

HOSPITAL COURSE

This patient affected by a severe gastroparesis was treated with antiemetics, prokinetics, analgesics and gastric electrical stimulation to control symptoms. Nutritional support was made using jejunal feeding tube and, in the final stage of disease, with total parenteral nutrition. Autonomic studies revealed minimal heart rate variability and a disordered Valsalva manoeuvre although the enteric nervous system and the smooth muscle layer showed a normal appearance. Hospital courses were complicated by episodes of bacteraemia and fungemia. Serum antiphospholipid antibodies were noted but despite anticoagulation, she developed a pulmonary embolism and shortly thereafter the patient died. Autopsy revealed acute haemorrhagic Candida pneumonia with left main pulmonary artery thrombus. Sympathetic chain analysis revealed decreased myelinated axons with vacuolar degeneration and patchy inflammation consistent with Guillain-Barre syndrome. The evaluation of the enteric nervous system in the stomach and small bowel revealed no evidence of enteric neuropathy or myopathy.

CONCLUSION

A Guillain-Barre-like disease with gastroparesis following acute gastroenteritis is supported by physiological and autonomic studies with histological findings.

Is gastric electrical stimulation superior to standard pharmacologic therapy in improving GI symptoms, healthcare resources, and long-term health care benefits?

CONTEXT

Severe upper gastrointestinal (GI) motor disorders, including gastroparesis (GP), can consume significant health care resources. Many patients are refractory to traditional drug therapy.

OBJECTIVE

To compare symptoms, healthcare resource utilization and costs in two groups of patients with the symptoms of GP: those treated via gastric electrical stimulation (GES) and those treated with traditional pharmacological agents in an intensive outpatient program (MED).

DESIGN

A long-term comparison of patients with devices (n = 9) vs intensive medical therapy (n = 9).

SETTING AND PATIENTS

A total of 18 eligible patients with the symptoms of GP reported for 1-year baseline and long-term treatment for 3 years.

INTERVENTIONS

Patients with the symptoms of GP were treated by a GES or intensive medical therapy (MED).

MAIN OUTCOME MEASURES

GP Symptoms, healthcare resource utilization using investigator-derived independent outcome measure score (IDIOMS) and total hospital (inpatient and outpatient) billing costs.

RESULTS

Gastrointestinal symptoms were significantly different from baseline (F = 3.03, P < 0.017) with GP patients treated via GES showing more sustained improvement over 36 months than those treated via MED. Healthcare resource usage, measured via the IDIOMS, significantly improved at 12, 24 and 36 month follow-up for GES patients (F = 10.49, P < 0.001), compared with patients receiving medical therapy, who demonstrated further deterioration. GP patients treated via GES also proved superior to medical therapy at 24 and 36 months with regard to decreased costs (F = 4.85, P < 0.001). Within group comparisons indicated significantly reduced hospital days for both patient groups; however, no statistical differences were noted between groups in terms of hospital days. Three of nine patients in the MED group died primarily from i.v. access related problems; none of the GES patients died.

CONCLUSION

We conclude that GES is more effective in improving long-term GI symptoms and costs, and decreasing use of healthcare resources than intensive medical therapy, in this sample of patients with the symptoms of GP followed for 3 years. Certain patients with GP form a high-risk group in terms of costs, quality of life, morbidity and mortality.

Assessment of gastric electrical activity and autonomic function among diabetic and nondiabetic patients with symptoms of gastroesophageal reflux

Gastroesophageal reflux disease (GERD) may present differently in patients with diabetes mellitus (DM) than in nondiabetics (NDM). We compared three tests in two patient groups with GERD symptoms: a DM group (n = 10) and a NDM group (n = 13). The tests were 24-hr esophageal pH, autonomic function testing (AFT), and electrogastrography (EGG). Analysis of the 23 patients revealed the DM group had normal 24-hr pH values (9 of 10 patients, mean pH 3.1 +/- 1.7), while NDM displayed abnormal pH values (9 of 13 patients, mean pH 21.2 +/- 5.9). AFT results were abnormal in DM (demonstrating cholinergic/ adrenergic dysfunction), but normal in NDM. EGG values were abnormal in both groups (mean 3.31 +/- 0.1 in each). We conclude that in GERD-symptomatic patients, those with DM frequently have normal 24-hr pH, but abnormal autonomic functioning, in contrast to NDM, who have abnormal 24-hr pH but normal autonomic function. Both groups had identically abnormal mean EGG values.

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.

Autonomic function in cyclic vomiting syndrome and classic migraine

Cyclic vomiting syndrome is an idiopathic disorder characterized by attacks of severe vomiting, interspersed with normal periods, and found in patients with a family history of migraine headaches. In this report, we investigated the characterization of the autonomic abnormalities in cyclic vomiting syndrome, contrasting them with values in pediatric population, as well as adults with migraine headache. We studied five groups: 41 normal pediatric controls (NPC), 12 patients with pediatric chronic vomiting (PCV), 15 patients with cyclic vomiting syndrome (CVS), 21 adults patients with migraine headaches (MHA), and 40 normal adult controls (NAC). We studied the sympathetic and cholinergic functions: two measures of sympathetic adrenergic function-vasoconstriction to cold and postural adjustment ratio; two measures of vagal cholinergic function--Valsalva ratio and ECG R-R interval; and one measure of total autonomic score. Comparisons were performed between and within groups by t tests and reported as mean +/- SEM. Although cholinergic function measures were lower in cyclic vomiting and migraine groups, the most distinct abnormality was low postural adjustment ratio in both cyclic vomiting and migraine groups vs normal pediatric and pediatric chronic vomiting groups. There was also a significant difference between cyclic vomiting and pediatric chronic vomiting groups (P < 0.05 in three other parameters). Cyclic vomiting syndrome is associated with distinctive adrenergic autonomic abnormalities similar to those in patients with migraine headaches and is usually characterized by a low postural adjustment ratio. These findings may have implications for both confirmation and diagnosis of cyclic vomiting syndrome.

Effect of leuprolide acetate in treatment of abdominal pain and nausea in premenopausal women with functional bowel disease: a double-blind, placebo-controlled, randomized study

We have previously reported impressive results in using a gonadotropin-releasing hormone analog, leuprolide acetate (Lupron), in the treatment of moderate to severe symptoms (especially abdominal pain and nausea) in patients with functional bowel disease (FBD). Pain is the hallmark of patients with FBD, and there is no consistent therapy for the treatment of these patients. The purpose of the present study was to expand the investigation to study similar patients (menstruating females) in a multicenter, double-blind, placebo-controlled, randomized study using Lupron Depot (which delivers a continuous dose of drug for one month), 3.75 mg (N = 32) or 7.5 mg (N = 33), or placebo (N = 35) given intramuscularly every four weeks for 16 weeks. Symptoms were assessed using daily diary cards to record abdominal pain, nausea, vomiting, early satiety, anorexia, bloating, and altered bowel habits. Additional assessment tools were quality of life questionnaires, psychological profile, oral-to-cecal transit using the hydrogen breath test, antroduodenal manometry, reproductive hormone levels, and global evaluations by both patient and investigator. Patients in both Lupron Depot-treated groups showed consistent improvement in symptoms; however, only the Lupron Depot 7.5 mg group showed a significant improvement for abdominal pain and nausea compared to placebo (P < 0.001). Patient quality of life assessments and global evaluations completed by both patient and investigators were highly significant compared to placebo (P < 0.001). All reproductive hormone levels significantly decreased for both Lupron Depot-treated groups by week 4 and were significantly different compared to placebo at week 16 (P < 0.001). This study shows that leuprolide acetate is effective in controlling the debilitating symptoms of abdominal pain and nausea in patients with FBD.

Biliary, pancreatic, and sphincter of Oddi electrical and mechanical signals recorded during ERCP

Measurements of biliary tract motility have focused on radiologic and pressure measurements to quantify biliary motility rather than measurements of electrical activity of the biliary tract. We previously reported the recording of biliary electrical signals during ERCP and now report on the continued development and validation of a system to measure biliary tract electrical activity as well as biliary mechanical activity. In 26 patients presenting with a variety of clinical indications, we recorded measurements of electrical activity from the common bile duct sphincter (16 patients), pancreatic duct sphincter (eight patients), and/or sphincter of Oddi (eight patients). Electrical recordings were performed with a specially modified ERCP catheter, using two circular electrodes as well as a custom catheter that measured both electrical and mechanical activity. Electrical activity of the biliary tract was successfully recorded in 25 of 26 patients (96%), including the common bile duct sphincter (16 patients, 62%), pancreatic duct sphincter (eight patients, 31%) and sphincter of Oddi (eight patients, 31%). Along with the electrical recordings, common bile duct sphincter mechanical activity was recorded in 12 patients (67%), pancreatic duct sphincter mechanical activity in six patients (33%), and sphincter of Oddi mechanical activity in six patients (33%). Frequency analysis of electrical signals revealed a mean frequency (cycles/min) of 4.7 +/- 0.5 in the common bile duct sphincter, 4.1 +/- 0.6 in the pancreatic duct sphincter, and 4.9 +/- 0.7 in the sphincter of Oddi. Phasic mechanical frequency in cycles per minute was recorded at a frequency of 4.8 +/- 0.5 in common bile duct sphincter, 4.0 +/- 0.6 in pancreatic duct sphincter, and 5.3 +/- 0.9 in sphincter of Oddi. Tonic pressure (averaged 12.1 +/- 1.5 mm Hg) in common bile duct sphincter, 12.4 +/- 1.4 mm Hg in pancreatic duct sphincter, and 15.0 +/- 5.1 mm Hg in sphincter of Oddi. Analysis of wave form propagations (noted as percentage antegrade, retrograde, or indeterminant) revealed 50% antegrade, 23% retrograde, and 27% indeterminant). One patient was recorded on two occasions via ERCP; the same patient had an intraoperative recording. All three recordings showed similarities. We conclude that measurements of biliary, pancreatic, and sphincter of Oddi electrical and mechanical activity are feasible and can be done as part of ERCP. There was good correlation between biliary tract electrical and mechanical events and different wave form characteristics were noted for different parts of the biliary tree. Further studies are warranted to evaluate the potential usefulness of measurement of biliary tract electrical activity, and to confirm its correlation with mechanical events in the pancreato-biliary tree.

Efficacy of electrical stimulation at frequencies higher than basal rate in canine stomach

The optimum frequency for electrically stimulating motility in the stomach is still in question. Some studies of gastric electrical stimulation (GES) at near physiologic frequencies have reported gastric electrical entrainment but with little efficacy in improving motility. In this study we examined the effectiveness of electrical stimulation at a broad range of frequencies in entraining gastric electrical activity (GEA) and eliciting contractions in a canine model. The stomachs of six dogs, each implanted with four pairs of stainless steel electrodes and two strain gauges were stimulated at frequencies ranging from 3 to 30 cycles/min. GEA and contractions were monitored before and during electrical stimulation. The ability of GES at different frequencies to reverse the effect of glucagon was also investigated. GEA was entrained in most animals at frequencies close to the intrinsic rate as well as at four to five times the intrinsic rate. At other stimulation frequencies, the recorded electrical control activity either remained unchanged, uncoupled, or became dysrhythmic. Contractile response to stimulation at four to five times the intrinsic rate were significantly higher than those at frequencies close to the intrinsic rate (P < 0.05). GES did not alter the effect of glucagon. Stimulation at a frequency of four times the basal rate of 5/min elicited the largest motility index in dogs. Stimulation at frequencies much higher than the physiologic rate warrants further study as a possible optimum range for GES.

Symptom improvement from prokinetic therapy corresponds to improved quality of life in patients with severe dyspepsia

Prokinetic therapy has been shown to improve patients' symptoms associated with gastrointestinal motility disorders and quality of life. This study investigated the correlation between clinical improvement and quality of life after 12 months of treatment with cisapride or domperidone in patients with severe dyspepsia. Psychological and quality-of-life measures were assessed at baseline and after 12 months of therapy using three patient-administered, standardized questionnaires: the Minnesota Multiphasic Personality Inventory, the Millon Behavioral Health Inventory, and the Sickness Impact Profile. Changes in clinical symptoms were correlated with changes in these measures. Twenty-seven patients with symptoms of severe dyspepsia were treated with cisapride or domperidone (60-80 mg/day) for 12 months. Symptoms and quality-of-life measures were improved at the end of therapy. There were significant correlations between improvement in clinical symptoms and improvement in quality of life parameters. Patients with more marked symptom improvement had more significant improvements in quality of life measures. We conclude that prokinetic therapy improved symptoms and quality of life. Standardized questionnaires can be used to quantify response to prokinetic therapy and to individualize treatment regimens for patients with dyspepsia who have specific psychologic or behavioral characteristics.

Gastrointestinal motility disorders

A careful history can localize gastrointestinal motility disorders and suggest appropriate diagnostic tests. Dysphagia, odynophagia, heartburn and reflux have esophageal origins. The same symptoms occur in achalasia, a classic motor disorder of the lower esophageal sphincter, which can be diagnosed by barium swallow, endoscopy and esophageal motility studies. Nausea, vomiting, anorexia, bloating and abdominal pain are symptoms of motor disorders of the stomach and small intestine. When these symptoms are accompanied by unexplained right upper quadrant pain, elevated liver enzyme levels and unexplained recurrent pancreatitis, the diagnosis of impaired biliary motility is suggested. Colorectal motility disorders may present as abdominal pain, diarrhea, constipation and/or fecal incontinence. If symptoms do not resolve with dietary changes and appropriate medications and the anatomy is normal on lower gastrointestinal studies, colorectal motility studies may be indicated.

A model of gastric electrical activity in health and disease

The idea of diagnosing gastric dysfunction from noninvasive measurements of gastric electrical activity (GEA) is intuitively appealing, but the predictive accuracy of the cutaneous signal, especially that of its amplitude, is still in question. Mathematical modeling provides a means of investigating, analyzing, and predicting GEA measured percutaneously. In this study, a model of GEA applicable both in health and disease was developed and simulated for a cylindrical body surface. Body-surface maps of the simulated electrogastrogram (EGG) were generated at a 20 by 20 array of sites on the model's surface, and the accuracy of the percutaneous method in detecting simulated gastric electrical abnormalities was determined. The relationship between the amplitude of the simulated surface EGG and the velocity of propagation of the myogenic activity was also investigated. This was compared to a similar investigation of the fluctuations in the amplitude of the surface EGG with the velocity of propagation of the serosal activity measured in humans. The diagnostic accuracy of the measured cutaneous EGG in humans was also determined. The results obtained from the mathematical model show that the amplitude of the electrogastrogram increases with the propagation velocity of GEA. Similar results were obtained from the experimental measurements. The amplitude of the simulated and measured cutaneous signal correlated well (p < 0.05) with the phase shift of the simulated and measured activities, (-0.85, -0.54), respectively. Serosal normal activity, tachygastria, and uncoupling were detected 67%, 90%, and 0% of the time, respectively, at the cutaneous electrode in humans. In simulations, normal activity and tachygastria were accurately detected at all 400 sites on the surface. Uncoupling simulated with 50% of the myogenic sources "diseased" was detected at only 20 of the 400 sites. The results confirm that the amplitude of the cutaneous signal is a function of the velocity of propagation of the myogenic signal. It also confirms that while GEA in health may be accurately predicted from percutaneous recordings, frequency and phase/coupling abnormalities are poorly detected from single-channel electrogastrograms. This suggests the use of multiple-channel surface recordings in clinical electrogastrography.

Measurement of gastric and small bowel electrical activity at laparoscopy

Recordings of gastric electrical activity can be employed in the diagnosis of certain gastric motility disorders. Since the best recordings are obtained from electrodes implanted at laparotomy, the scope of application of this technique is limited. The current study details a method of measuring gastric electrical activity at laparoscopy. The patients were 3 Caucasian women whose age range was 16 to 30 years. Their pertinent history included symptoms of nausea, vomiting, constipation, and abdominal pain. Gastric and small bowel electrical activity was measured with stainless steel electrodes implanted into the serosa of the stomach and small bowel at laparoscopy. Laparoscopy was performed for small bowel biopsy, bowel resection, or feeding tube placement. The recorded signals were evaluated by manual analysis. Good quality gastric and small bowel electrical activities were obtained. Amplitude, frequency, rhythmicity, and direction of propagation information were readily obtained by visual inspection. Laparoscopic measurement of gastric electrical activity produces excellent quality recordings comparable with recordings from electrodes implanted at laparostomy. The technique combines the advantage of laparoscopy with the usefulness of serosal measurement of gastrointestinal electrical activity.

Predominant symptoms in irritable bowel syndrome correlate with specific autonomic nervous system abnormalities

BACKGROUND/AIMS

Irritable bowel syndrome may be influenced by the autonomic nervous system. Abnormalities in autonomic function, colon transit time, and psychological profiles in 21 patients were assessed.

METHODS

Using modified Manning criteria for irritable bowel syndrome, patients were classified as constipation-predominant or diarrhea-predominant. Autonomic function was determined by one vagal cholinergic and two sympathetic adrenergic measures. Colon transit was assessed by radiopaque markers, and psychological profiles were determined by three inventories.

RESULTS

Autonomic function tests showed that diarrhea-predominant subgroup values for one sympathetic adrenergic measure (postural adjustment ratio) were significantly different from controls (P < 0.01). Constipation-predominant subgroup values were significantly lower for the vagal cholinergic measure R-R interval (P < 0.05). Colon transit measures differed by subgroup in left, right, rectosigmoid, and total colon transit times. Both subgroups differed significantly from controls on psychological measures; the constipation subgroup showed more psychological distress.

CONCLUSIONS

Irritable bowel syndrome specific-symptom subgroups had different patterns of autonomic functioning, colonic transit, and psychological measures. The constipation subgroup is associated with a cholinergic abnormality and the diarrhea-predominant subgroup with an adrenergic abnormality. These findings suggest specific associations between the autonomic nervous system, predominant physical symptoms, colon transit time, and psychological factors in patients with irritable bowel syndrome.

Cutaneous exposure to warfarin-like anticoagulant causing an intracerebral hemorrhage: a case report

A case of intercerebral hematoma due to warfarin-induced coagulopathy is presented. The 39-year-old woman had spread a warfarin-type rat poison around her house weekly using her bare hands, with no washing post application. Percutaneous absorption of warfarin causing coagulopathy, reported three times in the past, is a significant risk if protective measures, such as gloves, are not used. An adverse drug interaction with piroxicam, which she took occasionally, may have exacerbated the coagulopathy.

Effect of cisapride therapy for severe dyspepsia on gastrointestinal symptoms and quality of life

Quality of life measures have received little attention in evaluation of therapy for dyspepsia. To examine the effect of cisapride on gastrointestinal symptoms and quality of life measures, we studied eight patients with chronic, severe dyspepsia, before and after therapy with cisapride (20 mg three times daily) for 12 months. Gastrointestinal (GI) Total Symptom Score (TSS), Overall Patient Assessment (OPA), and quality of life by both trait (Minnesota Multiphasic Personality Inventory (MMPI)) and physical function (Sickness Impact Profile (SIP)) were measured at base line and at month 12 of cisapride therapy. Results showed significant improvement in TSS, OPA, and the MMPI Depression and Anxiety scales (all, p < 0.05). Improvement in the SIP physical dimension score approached significance (p = 0.065). We conclude that, in this group of patients with severe dyspepsia, both GI symptoms and quality of life measures improved with 12 months of cisapride therapy. These quality of life measures may prove useful in evaluating the efficacy of drug treatment for dyspepsia.

Hyperemesis gravidarum

Hyperemesis gravidarum is a poorly understood disorder and one for which many physicians have little sympathy, perhaps because we find it difficult to understand its pathogenesis and to treat. It may be associated with dysfunction in a variety of organs, including the thyroid and liver. Many theories, prominently including psychological or behavioral abnormalities, have been proposed to explicate this syndrome. On examination, however, no single theory seems to provide an adequate explanation for hyperemesis gravidarum. Treatment for hyperemesis gravidarum includes fluid and electrolyte supplementation, nutritional support, and total parenteral nutrition, as well as psychological and behavioral therapies and, in selected cases, pharmacotherapy.

Long-term efficacy of oral cisapride in symptomatic upper gut dysmotility

We conducted a 12-month trial of cisapride (10 mg three times a day) in 21 patients with gastric stasis due to clinically and manometrically diagnosed gastroparesis (N = 9; seven due to diabetes) or chronic intestinal pseudo-obstruction (N = 12). Radionuclide solid-liquid gastric emptying tests were performed at baseline and at the end of the 12-month period. Symptoms were assessed monthly by diary and every three months by the investigators; frequency and severity of symptoms were scored in a standardized manner. For the whole group of 21 patients, gastric emptying of both solids and liquids improved significantly after one year of cisapride (P less than 0.05). Among chronic intestinal pseudoobstruction patients, there was predominantly an improvement in gastric emptying of solids; in contrast, patients with gastroparesis had a greater improvement in liquid emptying. Total symptom score improved significantly in the gastroparesis group (median score: 8 at baseline vs 6 at one year, P less than 0.05) but not in the chronic intestinal pseudoobstruction patients (median score at baseline 10 vs 9 at one year). Similarly, body weight showed a trend towards improvement in the gastroparesis group. No significant side effects were noted. We conclude that during a 12-month open trial, cisapride was effective in improving gastric emptying in patients with gastric stasis and consistently improved symptoms in those with gastroparesis.

Changes in gastric emptying in recipients of successful combined pancreas-kidney transplants

Gastroparesis causes gastric emptying disorders in patients with chronic diabetes mellitus and it results from reduced smooth muscle contractility secondary to autonomic dysfunction. Today there has been little objective evidence of improvement in gastric emptying following correction of both uremia and diabetes by combined kidney-pancreas transplantation. We used gastrointestinal symptom scores, solid gastric emptying tests and electrogastrography to evaluate the effect of combined kidney-pancreas transplantation on gastric emptying in 8 uremic diabetic patients. The mean age of the patients was 40 years (range: 30-51 years) and the mean duration of diabetes was 24 years (range: 16-30 years). The patients had been on dialysis up to 24 months. The pretransplant A1 mean was 6.5 before improving to 4.3 after transplantation. All patients were receiving exogenous insulin. Our study data indicate that uremic diabetics have a high prevalence of symptomatic gastrointestinal dysfunction including abnormalities of gastric emptying and gastric electrical activity. Following transplantation, the gastrointestinal symptomatology improved significantly. Significant improvement in the rate of gastric emptying also correlated with improvement in the symptom complex. Gastric electrical activity also improved during the follow-up period.

Effect of six weeks of treatment with cisapride in gastroparesis and intestinal pseudoobstruction

We have investigated the effect of oral cisapride (10 mg t.i.d.) in a double-blind, placebo-controlled trial in 26 patients with upper gut dysmotility: 11 with gastroparesis (8 diabetic, 3 idiopathic) and 15 with chronic idiopathic intestinal pseudoobstruction. Patients were evaluated at entry and at the end of the 6-wk study by upper gastrointestinal manometry, scintigraphic evaluation of gastric emptying of solids and liquids, measurement of body weight, and scoring of the following symptoms: abdominal pain, nausea, vomiting, early satiety, bloating, and distention. Cisapride and placebo groups were strictly comparable for all parameters assessed. Cisapride resulted in a significant increase in the gastric emptying of solids (p less than 0.05) compared with placebo; cisapride also tended to increase the postcibal antral motility and normalize the abnormal manometric features in the patients with intestinal dysmotility, particularly the characteristics of fasting interdigestive motor complexes and the fed motor pattern. Both cisapride and placebo groups showed an improvement in total symptom scores and there was no significant difference in overall symptom response between the two groups. However, the change in abdominal pain was greater with cisapride (p = 0.07). Cisapride facilitates gastric emptying in patients with upper gut dysmotility. The overall symptomatic benefit during a 6-wk trial of cisapride, 10 mg t.i.d., was not greater than that of placebo, and dose-response as well as longer term trials are necessary to determine the clinical efficacy of this medication.

Effect of inhibition of prostaglandin synthesis on epinephrine-induced gastroduodenal electromechanical changes in humans

We conducted a double-blind randomized study to investigate the role of endogenous prostaglandins in epinephrine-induced changes in human gastric electromechanical activity. Intravenous administration of a pharmacologic dosage of epinephrine (222 ng/kg per min) caused gastric dysrhythmia in 8 of 12 healthy subjects. After indomethacin treatment, the incidence of epinephrine-induced gastric dysrhythmia was reduced to 4 of 12 healthy subjects, which is similar to the incidence of gastric dysrhythmia noted in the placebo group. The difference, however, was not statistically significant (P = 0.2). Epinephrine also substantially inhibited both the amplitude and the frequency of antral contractions. Indomethacin treatment partially reversed the reduction in the amplitude but not the frequency of antral contractions. These results suggest that endogenous prostaglandins may, in part, regulate the amplitude of human antral contractions; however, the role of prostaglandins in epinephrine-induced gastric dysrhythmia in humans remains uncertain.

Idiopathic cyclic nausea and vomiting--a disorder of gastrointestinal motility?

Eight patients (five men and three women) with previously unexplained recurrent cyclic episodes of nausea and vomiting are described. In these patients, the symptoms developed a mean of once every 3.2 months and persisted a mean of 3.5 days. None of the patients had an identifiable cause of their symptoms on conventional diagnostic tests. A detailed investigation of the gastrointestinal motility during an asymptomatic period revealed abnormal findings in all eight patients. Gastric hypomotility was substantiated in five patients, small bowel dysmotility in six, delayed gastric emptying in two, and gastric dysrhythmia in two. The data demonstrate that abnormal gastrointestinal motility occurs during an asymptomatic state in patients with cyclic episodes of nausea and vomiting. Because all patients with this syndrome had abnormal gastrointestinal motility but normal results of other gastrointestinal studies, idiopathic cyclic nausea and vomiting may be related to altered gastrointestinal motility.

Gastric electromechanical and neurohormonal function in anorexia nervosa

The gastrointestinal motor function in patients with anorexia nervosa is poorly understood, although it may be relevant to the pathophysiology of the disorder. We have undertaken a multidisciplinary study of 8 patients with anorexia nervosa and 8 age- and sex-matched controls. We have characterized their gastrointestinal and neurohormonal function by measuring (a) gastric electrical activity, (b) antral phasic pressure activity, (c) gastric emptying of solids and liquids, and (d) hormonal and autonomic function. Patients with anorexia nervosa at the time of the initiation of therapy presented with (a) increased episodes of gastric dysrhythmia (mean percentage of dysrhythmic time: 9.75 patients vs. 0.48 controls during fasting, p less than 0.02; 7.21 patients vs. 0.18 controls postcibally, p less than 0.001), (b) impaired antral contractility (mean motility index, 12.8 patients vs. 14.2 controls, p less than 0.002), (c) delayed emptying of solids, (d) decreased postcibal blood levels of norepinephrine and neurotensin (levels of beta-endorphin, insulin, glucagon, gastric inhibitory polypeptide, gastrin, cholecystokinin, and human pancreatic polypeptide were normal), and (e) impaired autonomic function (resting diastolic blood pressure and skin conductance were decreased and the response to the cold pressor test was dampened). Differences between patient and control groups were statistically significant. We conclude that patients with anorexia nervosa present multiple gastrointestinal abnormalities involving control mechanisms as well as target organs.

The rumination syndrome in adults. A characteristic manometric pattern

The rumination syndrome is defined as a process in which a person chews regurgitated gastric contents and then either partially ejects or swallows them. We report 12 cases of rumination in which the clinical diagnosis was supported by esophageal and gastrointestinal motility studies. These patients showed a characteristic pressure spike-wave pattern that was associated with regurgitation and was recorded simultaneously at all manometric sites. These spike waves increased significantly in frequency (p less than 0.001) and amplitude (p less than 0.04) during the postprandial period. The underlying gastrointestinal motility was normal except for a small decrease in postprandial antral motility index, with mean (+/- SE) values of 13.2 +/- 0.3 for patients compared with 14.2 +/- 0.3 for eight healthy adult controls (p less than 0.03). Nine patients had significant personality disturbances, including six whose scores on the Minnesota Multiphasic Personality Inventory for hypochondriasis and depression were significantly above the reference population (p less than 0.02). The rumination syndrome should be considered in adult patients with long-standing postprandial vomiting. The manometric pattern is characteristic.

Entamoeba polecki infection in Southeast Asian refugees: multiple cases of a rarely reported parasite

Recently, Entamoeba polecki was identified for the first time in our parasitology laboratory in stool specimens from eight Southeast Asian refugees. This ameba has been reported infrequently in the Western world; most reported cases have been from the New Guinea region. In most previously described patients and in our patients, no definite gastrointestinal symptoms could be directly attributed to E. polecki infection. Morphologically, E. polecki may mimic the pathogen E. histolytica and also nonpathogens such as E. coli. These species are most readily distinguished by studying encysted forms. In contrast to E. histolytica and E. coli, E. polecki characteristically has uninucleate cysts. Both pigs and monkeys naturally harbor E. polecki, but four of the patients in this series had no apparent contact with these animals. Other modes of infection may be human-to-human transmission or acquisition from other domestic animals. Six of our eight patients were treated successfully with one course of metronidazole in a regimen similar to that used for E. histolytica infection. In the two other patients, repeated courses of therapy eradicated the infection. Because of the recent increase in number of Southeast Asian immigrants to the United States, E. polecki may be identified more frequently than in the past. Physicians and laboratory personnel should be familiar with this organism, because it may be confused with E. histolytica or may act as a pathogen.

Glucagon-evoked gastric dysrhythmias in humans shown by an improved electrogastrographic technique

The objective of this study was to improve recording techniques for the recognition of gastric electrical dysrhythmias, and to explore the potential of pharmacologic agents to "evoke" gastric dysrhythmias. Eighteen healthy volunteers participated in 22 individual recordings, divided into two separate studies--a dose-response study and a randomized, double-blind study. The internal or mucosal electrogastrogram was recorded with a novel approach, using magnetic force to maintain internal electrodes in apposition with the gastric wall, whereas the external or cutaneous electrogastrogram, manometric activity, and respiration were measured by conventional methods. Analysis of simultaneous internal and external electrogastrographic signals, including both dysrhythmia and dysrhythmia-free intervals, revealed a good correspondence between the internal and external signals. In the dose-response study, 5 of the 6 volunteers intravenously infused with glucagon, in doses ranging from 3 to 22 micrograms/kg, developed gastric electrical dysrhythmias. In the randomized, double-blind study, 4 of 5 volunteers intravenously infused with glucagon (7 micrograms/kg) developed gastric dysrhythmias that were recognized by our improved techniques. Dysrhythmias, defined by visual analysis, consisted either of "tachygastria" (greater than or equal to 6 cycles/min for greater than or equal to 1 min) or "bradygastria" (greater than or equal to 1 cycle/min for greater than or equal to 1 min) and were evident on both internal and external electrogastrograms. Dysrhythmias were usually associated with absence of antral phasic pressure activity and frequently with nausea.