Idiopathic and Diabetic Gastroparesis

Bayesian inverse methods for spatiotemporal characterization of gastric electrical activity from cutaneous multi-electrode recordings

Gastrointestinal (GI) problems give rise to 10 percent of initial patient visits to their physician. Although blockages and infections are easy to diagnose, more than half of GI disorders involve abnormal functioning of the GI tract, where diagnosis entails subjective symptom-based questionnaires or objective but invasive, intermittent procedures in specialized centers. Although common procedures capture motor aspects of gastric function, which do not correlate with symptoms or treatment response, recent findings with invasive electrical recordings show that spatiotemporal patterns of the gastric slow wave are associated with diagnosis, symptoms, and treatment response. We here consider developing non-invasive approaches to extract this information. Using CT scans from human subjects, we simulate normative and disordered gastric surface electrical activity along with associated abdominal activity. We employ Bayesian inference to solve the ill-posed inverse problem of estimating gastric surface activity from cutaneous recordings. We utilize a prior distribution on the spatiotemporal activity pertaining to sparsity in the number of wavefronts on the stomach surface, and smooth evolution of these wavefronts across time. We implement an efficient procedure to construct the Bayes optimal estimate and demonstrate its superiority compared to other commonly used inverse methods, for both normal and disordered gastric activity. Region-specific wave direction information is calculated and consistent with the simulated normative and disordered cases. We apply these methods to cutaneous multi-electrode recordings of two human subjects with the same clinical description of motor function, but different diagnosis of underlying cause. Our method finds statistically significant wave propagation in all stomach regions for both subjects, anterograde activity throughout for the subject with diabetic gastroparesis, and retrograde activity in some regions for the subject with idiopathic gastroparesis. These findings provide a further step towards towards non-invasive phenotyping of gastric function and indicate the long-term potential for enabling population health opportunities with objective GI assessment.

Gastroparesis in Non-Diabetics: Associated Conditions and Possible Risk Factors

Background

Gastroparesis is a syndrome characterized by delayed gastric emptying in the absence of any mechanical cause. While often associated with diabetes mellitus, most cases of gastroparesis are idiopathic. The purpose of the present paper is to review the co-morbid conditions that most likely associate with non-diabetic gastroparesis.

Methods

The Healthcare Cost and Utilization Project: Nationwide Inpatient Sample (HCUP-NIS) data were used from the year 2013 - 2014 and the Apriori algorithm was run on this subset of patients to identify what co-morbid conditions are most likely associated with gastroparesis.

Results

Notable conditions that were found to be most closely linked with gastroparesis were: chronic pancreatitis, end stage renal disease, irritable bowel syndrome, systemic lupus erythematosus, fibromyalgia, and venous thromboembolism. Some of the implications of these findings are briefly discussed.

Conclusions

Gastroparesis is strongly associated with multiple medical conditions which may be potential targets for treatment.

The Vomiting Patient: Small Bowel Obstruction, Cyclic Vomiting, and Gastroparesis

Vomiting and abdominal pain are common in patients in the emergency department. This article focuses on small bowel obstruction (SBO), cyclic vomiting, and gastroparesis. Through early diagnosis and appropriate management, the morbidity and mortality associated with SBOs can be significantly reduced. Management of SBOs involves correction of physiologic and electrolyte disturbances, bowel rest and removing the source of the obstruction. Treatment of acute cyclic vomiting is primarily directed at symptom control, volume and electrolyte repletion, and appropriate specialist follow-up. The mainstay of therapy for gastroparesis is metoclopramide.

Management and prevention of delayed gastric emptying after pancreaticoduodenectomy

Although technical advances have been made in pancreaticoduodenectomy, the incidence of delayed gastric emptying (DGE) is reported as being high. Postoperative DGE is not fatal, but often results in prolonging the length of patients' stay in hospital, increasing their medical expenses, and further lowering their quality of life. DGE is a complex process caused by disorder and incoordination of various factors in charge of gastric mobility, such as smooth muscle cells (myogenic), enteric neuron (hormonal), and autonomic nervous system (neural). DGE often occurs after operative maneuvers that cause the loss of organs responsible for gastric motility and emptying or kinetic muscular or neuromuscular ischemia. To prevent DGE, it is most important to develop and universalize a standardized surgical technique in a way to reduce factors that are considered to cause DGE after pancreaticoduodenectomy. Moreover, if it is suspected that DGE occurred after pancreaticoduodenectomy, a differential diagnosis from diseases with similar symptoms via an accurate diagnostic approach should be implemented.

Gastroparesis: approach, diagnostic evaluation, and management

Gastroparesis is a chronic motility disorder of the stomach that involves delayed emptying of solids and liquids, without evidence of mechanical obstruction. Although no cause can be determined for the majority of cases, the disease often develops as a complication of abdominal surgeries or because of other underlying disorders, such as diabetes mellitus or scleroderma. The pathophysiology behind delayed gastric emptying is still not well-understood, but encompasses abnormalities at 3 levels--autonomic nervous system, smooth muscle cells, and enteric neurons. Patients will often cite nausea, vomiting, postprandial fullness, and early satiety as their most bothersome symptoms on history and physical examination. Those that present with severe disease may already have developed complications, such as the formation of bezoars or masses of undigested food. In patients suspected of gastroparesis, diagnostic evaluation requires an initial upper endoscopy to rule out mechanical causes, followed by a gastric-emptying scintigraphy for diagnosis. Other diagnostic alternatives would be wireless capsule motility, antroduodenal manometry, and breath testing. Once gastroparesis is diagnosed, dietary modifications, such as the recommendation of more frequent and more liquid-based meals, are encouraged. Promotility medications like erythromycin and antiemetics like prochlorperazine are offered for symptomatic relief. These agents may be frequently changed, as the right combination of effective medications will vary with each individual. In patients who are refractory to pharmacologic treatment, more invasive options, such as intrapyloric botulinum toxin injections, placement of a jejunostomy tube, or implantation of a gastric stimulator, are considered. Future areas of research are based on current findings from clinical studies. New medications, such as hemin therapy, are emerging because of a better understanding of the pathophysiology behind gastroparesis, and present treatment options, such as gastric electric stimulation, are evolving to be more effective. Regenerative medicine and stem cell-based therapies also hold promise for gastroparesis in the near future.

Not just another case of nausea and vomiting: a review of postinfectious gastroparesis

PURPOSE

To review the epidemiology, pathophysiology, clinical presentation, diagnosis, and treatment of postinfectious gastroparesis (PIGP).

DATA SOURCES

Review of literature using Medscape, the Internet, and PubMed. The following search terms were used: gastroparesis, postinfectious gastroparesis, postviral gastroparesis, and idiopathic gastroparesis. There was no limitation placed on publication year. Only articles in English were used.

CONCLUSIONS

PIGP is a rare illness that can affect all ages and both genders, although more prominent in middle-aged women. It is defined as delayed gastric emptying after an acute self-limited viral infection in the absence of mechanical obstruction. Limited research is available on PIGP. It is a complicated disorder with an unclear pathogenesis and narrow treatment options, therefore affecting the patient's quality of life significantly. Fortunately, the prognosis of PIGP is good, although in some instances it can take years to recover completely.

IMPLICATIONS FOR PRACTICE

There is a huge lack of awareness of PIGP among primary care providers (PCPs). The importance of this illness is greatly underestimated. Educating PCPs about PIGP leads to quicker referrals and therefore faster treatment for patients, which in turn improves their health and quality of life, and thereby decreases healthcare costs as well.

Diabetic gastroparesis-backwards and forwards

Diabetic gastroparesis was once thought to be rare, associated with a poor prognosis, and to affect only patients with type 1 diabetes and irreversible autonomic neuropathy. A landmark study conducted by Horowitz et al. and published in JGH in 1986 paved the way for further studies to examine the pathophysiology, natural history and prognosis of diabetic gastroparesis, as well as its optimal management. This review summarizes the developments in knowledge gained over the last ∼25 years that have led to understanding about normal and disordered gastric emptying in diabetes, with a particular emphasis on the inter-relationship between the rate of gastric emptying and the regulation of blood glucose.

Diabetes mellitus and gastric emptying: questions and issues in clinical practice

It is long known that both type 1 and type 2 diabetes can be associated with changes in gastric emptying; a number of publications have linked diabetes to delayed gastric emptying of variable severity and often with poor relationship to gastrointestinal symptomatology. In contrast, more recent studies have reported accelerated gastric emptying when adjusted for glucose concentration in patients with diabetes, indicating a reciprocal relationship between gastric emptying and ambient glucose concentrations. This review proposes that gastroparesis or gastroparesis diabeticorum, a severe condition characterized by a significant impairment of gastric emptying accompanied by severe nausea, vomiting, and malnutrition, is often overdiagnosed and not well contrasted with delays in gastric emptying. The article offers a clinically relevant definition of gastroparesis that should help differentiate this rare condition from (often asymptomatic) delays in gastric emptying. The fact that delayed gastric emptying can also be observed in non-diabetic individuals under experimental conditions in which hyperglycaemia is artificially induced suggests that a delay in gastric emptying rate when blood glucose concentrations are high is actually an appropriate physiological response to hyperglycaemia, slowing further increases in blood glucose. The article discusses the strengths and weaknesses of various methodologies for assessing gastric emptying, especially with respect to the diabetes population, and reviews newer diabetes therapies that decelerate the rate of gastric emptying. These therapies may be a beneficial tool in managing postprandial hyperglycaemia because they attenuate rapid surges in glucose concentrations by slowing the delivery of meal-derived glucose.

Diabetic gastroparesis: diagnosis and management

Gastric emptying is frequently abnormal in patients with long-standing type 1 and type 2 diabetes mellitus. Symptoms commonly associated with disordered gastric emptying include nausea, vomiting, bloating and epigastric pain, while patients are also at risk of malnutrition, weight loss, impaired drug absorption, disordered glycaemic control and poor quality of life. Although often attributed to the presence of irreversible autonomic neuropathy, acute hyperglycaemia represents a potentially reversible cause of gastric dysfunction in diabetes. Scintigraphy represents the gold standard for measuring gastric emptying. The management of diabetic gastroparesis is less than optimal, partly because the pathogenesis has not been clearly defined. Treatment approaches include dietary modification and optimization of glycaemia, and the use of prokinetic drugs, while novel therapies such as gastric electrical stimulation are the subject of ongoing investigation.

Diagnostic and therapeutic approach to pancreatic cancer-associated gastroparesis: literature review and our experience

BACKGROUND

Patients with unresectable pancreatic carcinoma often present with early satiety, nausea, and vomiting without evidence of mechanical obstruction, mucosal disease, or metabolic abnormality. This condition is well described in the literature and is thought to result from pancreatic cancer-associated gastroparesis (PCAG). No clinical guideline is available for diagnosing and managing this rare disease.

OBJECTIVE

To propose an algorithm for diagnosing and managing patients with PCAG based on a literature review and our clinical experience.

METHODS

A comprehensive review was conducted of literature on the subject from 1966 to 2005, and retrospective analysis was performed for patients with PCAG who presented to the University of Iowa Hospitals and Clinics (Iowa City, IA, USA) during the period 1998-2005.

RESULTS

Literature on an optimal diagnostic and therapeutic approach to PCAG is lacking. There are only two small case series and one case report regarding management of PCAG. Extensive chart review only identified two patients who met the diagnostic criteria of PCAG. We propose performing routine upper GI series and esophagogastroduodenoscopy on all patients with pancreatic cancer who present with nausea and vomiting, to rule out obstruction and mucosal disease. If there is no obstruction or mucosal disease, we do not recommend further workup. Prokinetic agents are the first line therapy for PCAG. In refractory cases, percutaneous endoscopic gastrostomy with jejunal extension may be considered in selected patients who respond to nasojejunal decompression.

CONCLUSIONS

We propose a time-effective and useful strategy for diagnosing and managing patients with PCAG. We also define the diagnostic end-point for this difficult to manage condition.

Clinical application prospects of gastric pacing for treating postoperative gastric motility disorders

Similar to the heartbeat, gastric peristalsis is regulated by an electrical rhythm generated by a pacemaker. Thus, electrical dysrhythmia of gastric slow waves will inevitably affect gastric peristalsis and emptying. The recurrence of postoperative gastroparesis is thereby closely related to the abnormalities of electrical dysrhythmia and ectopic pacemakers, resulting in postoperatively persistent gastric motility disorders in some severe cases, despite the use of prokinetic and antiemetic drugs. Recent studies have demonstrated that gastric pacing, analogous to pacing the human heart, is an attractive and promising therapy that is both feasible and safe. Gastric pacing has been shown to be strikingly effective in normalizing gastric dysrhythmia, increasing the activity of the gastric slow wave and thereby prompting gastric dynamia and emptying. Furthermore, the long-term utilization of gastric pacing can (i) relieve patients from clinical symptoms, such as nausea and vomiting; (ii) release patients with severe postoperative gastroparesis from relying on prokinetic drugs and the jejunal feeding tube; (iii) return patients to normal oral nutritional intake and provide a more satisfactory nutritional status and most importantly; and (iv) give patients a better quality of life. Overall, research focused on gastric pacing has demonstrated excellent prospects for clinical application in the treatment of postoperative gastroparesis disorders, especially for those unresponsive to prokinetic drugs.

Gastric emptying, diabetes, and aging

Gastric emptying is mildly slowed in healthy aging, although generally remains within the normal range for young people. The significance of this is unclear, but may potentially influence the absorption of certain drugs, especially when a rapid effect is desired. Type 2 diabetes is common in the elderly, but there is little data regarding its natural history, prognosis, and management. This article focuses on the interactions between gastric emptying and diabetes, how each is influenced by the process of aging, and the implications for patient management.

Tricyclic antidepressants for chronic vomiting in diabetic patients

Chronic vomiting in diabetic patients often is unresponsive to prokinetic agents and poorly explained by delayed gastric emptying or neuropathy. This retrospective study examines clinical response to tricyclic antidepressants, a treatment of reported benefit in nondiabetic patients with unexplained vomiting syndromes. Outcomes were studied in 24 diabetic outpatients who had been treated with tricyclic antidepressants specifically for nausea and vomiting after an unsatisfactory response to prokinetic therapy. Symptom patterns and treatment response were determined from chart review and telephone interview. Ten patients (42%) had recurrent, stereotypical vomiting episodes with symptom-free intervals suggesting cyclic vomiting syndrome; 14 (58%) had persistent symptoms. By chart review, at least moderate symptom response to tricyclic antidepressant treatment (median dosage, 50 mg/day) occurred in 88% of subjects, with complete or nearly complete resolution of symptoms in one-third. At follow-up interview, 77% self-reported at least moderate symptom improvement during therapy and 68% rated tricyclic antidepressants the most effective treatment received. Duration of diabetes, presence of neuropathy, and psychiatric status were not predictive of treatment outcome in multivariate analysis, but a cyclical symptom pattern attenuated antidepressant response (P< 0.05). In this retrospective review, the majority of diabetic patients with chronic vomiting and incomplete response to prokinetic therapy benefited from tricyclic antidepressants in low-dose, open-label regimens and rated them the most effective treatment received. This therapeutic option should be further studied in diabetic patients considering the morbidity of chronic vomiting in this population.

Hypomagnesemia in patients with type 2 diabetes

Hypomagnesemia has been reported to occur at an increased frequency among patients with type 2 diabetes compared with their counterparts without diabetes. Despite numerous reports linking hypomagnesemia to chronic diabetic complications, attention to this issue is poor among clinicians. This article reviews the literature on the metabolism of magnesium, incidence of hypomagnesemia in patients with type 2 diabetes, implicated contributing factors, and associated complications. Hypomagnesemia occurs at an incidence of 13.5 to 47.7% among patients with type 2 diabetes. Poor dietary intake, autonomic dysfunction, altered insulin metabolism, glomerular hyperfiltration, osmotic diuresis, recurrent metabolic acidosis, hypophosphatemia, and hypokalemia may be contributory. Hypomagnesemia has been linked to poor glycemic control, coronary artery diseases, hypertension, diabetic retinopathy, nephropathy, neuropathy, and foot ulcerations. The increased incidence of hypomagnesemia among patients with type 2 diabetes presumably is multifactorial. Because current data suggest adverse outcomes in association with hypomagnesemia, it is prudent to monitor magnesium routinely in this patient population and treat the condition whenever possible.

Pathophysiology and management of diabetic gastropathy: a guide for endocrinologists

Delayed gastric emptying is frequently observed in patients with long-standing type 1 and type 2 diabetes mellitus, and potentially impacts on upper gastrointestinal symptoms, glycaemic control, nutrition and oral drug absorption. The pathogenesis remains unclear and management strategies are currently suboptimal. Therapeutic strategies focus on accelerating gastric emptying, controlling symptoms and improving glycaemic control. The potential adverse effects of hyperglycaemia on gastric emptying and upper gut symptoms indicate the importance of normalising blood glucose if possible. Nutritional and psychological supports are also important, but often neglected. A number of recent pharmacological and non-pharmacological therapies show promise, including gastric electrical stimulation. As with all chronic illnesses, a multidisciplinary approach to management is recommended, but there are few data regarding long-term outcomes.

Loss of interstitial cells of Cajal network in severe idiopathic gastroparesis

AIM: To report a case of severe idiopathic gastroparesis in complete absence of Kit-positive gastric interstitial cells of Cajal (ICC).

METHODS: Gastric tissue from a patient with severe idiopathic gastroparesis unresponsive to medical treatment and requiring surgery was analyzed by conventional histology and immunohistochemistry.

RESULTS: Gastric pacemaker cells expressing Kit receptor had completely disappeared while the local level of stem cell factor, the essential ligand for its development and maintenance, was increased. No signs of cell death were observed in the pacemaker region.

CONCLUSION: These results are consistent with the hypothesis that a lack of Kit expression may lead to impaired functioning of ICC. Total gastrectomy proves to be curative.

An integrative software package for gastrointestinal biomagnetic data acquisition and analysis using SQUID magnetometers

The study of bioelectric and biomagnetic activity in the human gastrointestinal (GI) tract is of great interest in clinical research due to the proven possibility to detect pathological conditions thereof from electric and magnetic field recordings. The magnetogastrogram (MGG) and magnetoenterogram (MENG) can be recorded using superconducting quantum interference device (SQUID) magnetometers, which are the most sensitive magnetic flux-to-voltage converters currently available. To address the urgent need for powerful acquisition and analysis software tools faced by many researchers and clinicians in this important area of investigation, an integrative and modular computer program was developed for the acquisition, processing and analysis of GI SQUID signals. In addition to a robust hardware implementation for efficient data acquisition, a number of signal processing and analysis modules were developed to serve in a variety of both clinical procedures and scientific investigations. Implemented software features include data processing and visualization, waterfall plots of signal frequency spectra as well as spatial maps of GI signal frequencies. Moreover, a software tool providing powerful 3D visualizations of GI signals was created using realistic models of the human torso and internal organs.

New management approaches for gastroparesis

Management of patients with gastroparesis is challenging. Although the syndrome has multiple causes and knowledge of the pathophysiology and natural history is far from complete, a number of common management principles can be applied. The relatively poor correlation between upper-gastrointestinal symptoms and disordered gastric emptying represents a major difficulty in the therapeutic approach, and evidence to support the efficacy of current management strategies is often suboptimal, especially in relation to long-term therapy. In this review, the common causes and pathophysiology of gastroparesis are summarized, the diagnostic approach considered, and the evidence to support medical and surgical therapies reviewed. These therapies include currently available prokinetic drugs, novel medical therapies, and the promising technique of gastric electrical stimulation.