Buspirone, a new drug for the management of patients with ineffective esophageal motility?

The Impact of Chronic Cannabis Use on Esophageal Motility in Patients Referred for Esophageal Manometry

BACKGROUND

Tetrahydrocannabinol, the main psychoactive compound in cannabis, binds with high affinity to the cannabinoid 1 receptor. Small randomized controlled studies using conventional manometry have shown that the cannabinoid 1 receptor can modulate esophageal function, namely transient lower esophageal sphincter relaxation frequency and lower esophageal sphincter tone. The effect of cannabinoids on esophageal motility in patients referred for esophageal manometry has not been fully elucidated using high-resolution esophageal manometry (HREM). We aimed to characterize the clinical effect of chronic cannabis use on esophageal motility utilizing HREM.

METHODS

Patients who underwent HREM from 2009 to 2019 were identified at 4 academic medical centers. The study group consisted of patients with a noted history of chronic cannabis use, a diagnosis of cannabis-related disorder, or a positive urine toxicology screen. Age and gender-matched patients with no history of cannabis use were selected to form the control group. Data on HREM metrics based on the Chicago classification V3, and the prevalence of esophageal motility disorders were compared. Confounding effects of BMI and medications on esophageal motility were adjusted for.

RESULTS

Chronic cannabis use was found to be an independent negative predictor of weak swallows (β=-8.02, P =0.0109), but not a predictor of failed swallows ( P =0.6890). The prevalence of ineffective esophageal motility was significantly lower in chronic cannabis users compared with nonusers (OR=0.44, 95% CI 0.19-0.93, P =0.0384). There was no significant difference in the prevalence of other esophageal motility disorders between the 2 cohorts. In patients with dysphagia as their primary indication for HREM, chronic cannabis use was found to be independently associated with increased median integrated relaxation pressure (β=6.638, P =0.0153) and increased mean lower esophageal sphincter resting pressure (β=10.38, P =0.0084).

CONCLUSIONS

Chronic cannabis use is associated with decreased weak swallows and reduced prevalence of ineffective esophageal motility in patients referred for esophageal manometry. In patients referred for dysphagia, chronic cannabis use is associated with increased integrated relaxation pressure and lower esophageal sphincter resting pressure, though not to levels above the normal range.

Systemic sclerosis gastrointestinal dysmotility: risk factors, pathophysiology, diagnosis and management

Nearly all patients with systemic sclerosis (SSc) are negatively affected by dysfunction in the gastrointestinal tract, and the severity of gastrointestinal disease in SSc correlates with high mortality. The clinical complications of this dysfunction are heterogeneous and include gastro-oesophageal reflux disease, gastroparesis, small intestinal bacterial overgrowth, intestinal pseudo-obstruction, malabsorption and the requirement for total parenteral nutrition. The abnormal gastrointestinal physiology that promotes the clinical manifestations of SSc gastrointestinal disease throughout the gastrointestinal tract are diverse and present a range of therapeutic targets. Furthermore, the armamentarium of medications and non-pharmacological interventions that can benefit affected patients has substantially expanded in the past 10 years, and research is increasingly focused in this area. Here, we review the details of the gastrointestinal complications in SSc, tie physiological abnormalities to clinical manifestations, detail the roles of standard and novel therapies and lay a foundation for future investigative work.

Evaluation of Therapeutic Effect of Buspirone in Improving Dysphagia in Patients with GERD and Ineffective Esophageal Motility: A Randomized Clinical Trial

Background: Ineffective esophageal motility (IEM) is the most common esophageal motility disorder associated with low-to-moderate amplitude contractions in the distal esophagus in manometric evaluations. Despite recent new conceptions regarding the pathophysiology of esophageal motility and IEM, there are still no effective therapeutic interventions for the treatment of this disorder. This study aimed to investigate the effect of buspirone in the treatment of concomitant IEM and GERD. Methods and Materials: The present study was a randomized clinical trial conducted at the Imam Khomeini Hospital, Tehran. Patients with a history of gastroesophageal reflux disease and dysphagia underwent upper endoscopy to rule out any mechanical obstruction and were diagnosed with an ineffective esophageal motility disorder based on high-resolution manometry. They were given a package containing the desired medication(s); half of the packets contained 10 mg (for 30 days) of buspirone and 40 mg (for 30 days) of pantoprazole, and the other half contained only 40 mg (for 30 days) of pantoprazole. Dysphagia was scored based on the Mayo score, as well as a table of dysphagia severity. Manometric variables were recorded before and after the treatment. Results: Thirty patients (15 pantoprazole and 15 pantoprazole plus buspirone) were included. Females comprised 63.3% of the population, with a mean age of 46.33 ± 11.15. The MAYO score and resting LES pressure significantly changed after treatment. The MAYO and Swallowing Disorder Questionnaire scores significantly decreased after treatment in both groups of patients. Our results revealed that the post-intervention values of manometric variables differed significantly between the two groups after controlling for the baseline values of the variables. This analysis did not demonstrate the superiority of buspirone. Conclusion: Buspirone seems to have no superiority over PPI. Treatment with concomitant IEM and GERD using proton pump inhibitors improves the patient’s clinical condition and quality of life. However, adding buspirone to the treatment regimen did not appear to make a significant difference in patient treatment.

Neurochemical classification of serotonin-immunoreactive neurons co-innervating motor endplates in the mouse esophagus

Serotonin immunoreactivity was previously found in myenteric neurons co-innervating motor endplates in the mouse esophagus striated muscle and an involvement in motility control was suggested. However, it is not known if other neuroactive substances are present in these neurons and to what extent they co-localize. First, vasoactive intestinal peptide (VIP) was established as a bona fide marker for putative inhibitory myenteric neurons by evaluating co-localization with neuronal nitric oxide synthase (nNOS) and neuropeptide Y (NPY). Then, co-localization of serotonin and VIP was tested in co-innervating axons on motor endplates, which were visualized with α-bungarotoxin (α-BT) by multilabel immunofluorescence. Myenteric ganglia were also surveyed for co-localization in neuronal perikarya and varicosities. nNOS, NPY, and VIP were completely co-localized in enteric co-innervating nerve terminals on motor endplates. After co-staining with VIP, we found (a) serotonin (5-HT)-positive nerve endings without VIP (44% of 5-HT-positively innervated endplates), (b) 5-HT- and VIP-positive endings without co-localization (35%), and (c) 5-HT- and VIP-positive endings with co-localization (21%). About one-fifth of nerve terminals on motor endplates containing 5-HT originate from putative inhibitory peptidegic nitrergic neurons. However, the majority represents a different population presumably subserving different functions.

Management of scleroderma gastrointestinal disease: Lights and shadows

Gastrointestinal symptoms affect the great majority of patients with systemic sclerosis. Management of these complications is often challenging as any region of the gastrointestinal tract may be involved, and significant heterogeneity exists in clinical presentation, kinetics, and outcomes. Here, we highlight new findings relevant to the management of systemic sclerosis-related gastrointestinal disease (lights) and consider areas that we have yet to elucidate (shadows).

Esophageal Motility Disorders: Current Approach to Diagnostics and Therapeutics

Dysphagia is a common symptom with significant impact on quality of life. Our diagnostic armamentarium was primarily limited to endoscopy and barium esophagram until the advent of manometric techniques in the 1970s, which provided the first reliable tool for assessment of esophageal motor function. Since that time, significant advances have been made over the last 3 decades in our understanding of various esophageal motility disorders due to improvement in diagnostics with high-resolution esophageal manometry. High-resolution esophageal manometry has improved the sensitivity for detecting achalasia and has also enhanced our understanding of spastic and hypomotility disorders of the esophageal body. In this review, we discuss the current approach to diagnosis and therapeutics of various esophageal motility disorders.

Impact of Surgical Intervention on Nonobstructive Dysphagia: A Retrospective Study Based on High-Resolution Impedance Manometry in a Taiwanese Population at a Single Institution

Esophageal motility disorders account for a large proportion of nonobstructive dysphagia cases, which constitute a heterogeneous group of diagnoses that commonly result in peristaltic derangement and impaired relaxation of the lower esophageal sphincter. We performed a single-institution retrospective study enrolling consecutive patients with chief complaints of dysphagia who underwent HRIM from December 2014 to December 2019, and analyzed demographic, clinical, and manometric data using descriptive statistics. In total, 277 identified patients were included in the final analysis. Ineffective esophageal motility (n = 152, 24.5%) was the most common diagnosis by HRIM, followed by absent contractility, EGJ outflow obstruction, type II achalasia, and type I achalasia. Furthermore, surgery including exploratory, laparoscopic, and robotic myotomy, as well as POEM, is considered the most effective treatment for patients with non-spastic achalasia and EGJOO, due to its effective symptom palliation and prevention of disease progression; surgery also contributes to an obvious improvement of dysphagia compared with slightly less efficacy for other related symptoms. Our study aimed to elaborate the clinical characteristics of patients with nonobstructive dysphagia based on HRIM in a Taiwanese population, and to analyze the therapeutic outcomes of such patients who ultimately underwent surgical interventions.

The mechanism of esophagus dysmotility in diabetes and research progress of relating treatments

Introduction: Esophagus dysmotility is a crucial risk factor of gastroesophageal reflux disease (GERD), which is one of the most common diseases in digestive medicine globally. This review emphasizes the mechanisms of esophagus dysmotility in diabetes and summarizes more targeted treatments for these patients to avoid the overuse of proton pump inhibitors (PPIs).Areas covered: Diabetes mellitus (DM) is a clear factor that must not be neglected in the development of GERD. Previous studies have preliminarily researched the esophagus deterioration in diabetes. However, the multi-faceted mechanisms of esophagus dysmotility in diabetes need more studies. Besides, targeted treatments for these patients rather than conventional PPIs are urgently needed.Expert opinion: The treatments for GERD patients with diabetes should be further explored. Pharmacological approaches such as prokinetic agents, psychotherapy can be adopted. Meanwhile, it's feasible to explore non-drug treatments. For example, Electroacupuncture (EA) at Zusanli (ST-36) may be effective to protect the networks of intestinal cells of Cajal (ICCs) in diabetes. More effective approaches should be explored to achieve individualized treatment for these patients.

Chicago Classification update (V4.0): Technical review on diagnostic criteria for ineffective esophageal motility and absent contractility

Esophageal hypomotility disorders manifest with abnormal esophageal body contraction vigor, breaks in peristaltic integrity, or failure of peristalsis in the context of normal lower esophageal sphincter relaxation on esophageal high-resolution manometry (HRM). The Chicago Classification version 4.0 recognizes two hypomotility disorders, ineffective esophageal motility (IEM) and absent contractility, while fragmented peristalsis has been incorporated into the IEM definition. Updated criteria for ineffective swallows consist of weak esophageal body contraction vigor measured using distal contractile integral (DCI, 100-450 mmHg·cm·s), transition zone defects >5 cm measured using a 20 mmHg isobaric contour, or failure of peristalsis (DCI < 100 mmHg·cm·s). More than 70% ineffective swallows and/or ≥50% failed swallows are required for a conclusive diagnosis of IEM. When the diagnosis is inconclusive (50%-70% ineffective swallows), supplementary evidence from multiple rapid swallows (absence of contraction reserve), barium radiography (abnormal bolus clearance), or HRM with impedance (abnormal bolus clearance) could support a diagnosis of IEM. Absent contractility requires 100% failed peristalsis, consistent with previous versions of the classification. Consideration needs to be given for the possibility of achalasia in absent contractility with dysphagia despite normal IRP, and alternate complementary tests (including timed upright barium esophagram and functional lumen imaging probe) are recommended to confirm or refute the presence of achalasia. Future research to quantify esophageal bolus retention on stationary HRM with impedance and to understand contraction vigor thresholds that predict bolus clearance will provide further refinement to diagnostic criteria for esophageal hypomotility disorders in future iterations of the Chicago Classification.

Pathophysiologic Role of Neurotransmitters in Digestive Diseases

Neurotransmitters are special molecules that serve as messengers in chemical synapses between neurons, cells, or receptors, including catecholamines, serotonin, dopamine, and other neurotransmitters, which play an important role in both human physiology and pathology. Compelling evidence has indicated that neurotransmitters have an important physiological role in various digestive diseases. They act as ligands in combination with central or peripheral receptors, and transmits signals through chemical synapses, which are involved in regulating the physiological and pathological processes of the digestive tract organs. For instance, neurotransmitters regulate blood circulation and affect intestinal movement, nutrient absorption, the gastrointestinal innate immune system, and the microbiome. In this review, we will focus on the role of neurotransmitters in the pathogenesis of digestive tract diseases to provide novel therapeutic targets for new drug development in digestive diseases.

Management of Ineffective Esophageal Hypomotility

Esophageal hypomotility in general and especially ineffective esophageal motility according to the Chicago criteria of primary motility disorders of the esophagus, is one of the most frequently diagnosed motility disorders on high resolution manometry and results in a large number of patients visiting gastroenterologists. Most patients with esophageal hypomotility present with gastroesophageal reflux symptoms or dysphagia. The clinical relevance of the motility pattern, however, is not well established but seems to be correlated with disease severity in reflux patients. The correlation with dysphagia is less clear. Prokinetic agents are commonly prescribed as first line pharmacologic intervention to target esophageal smooth muscle contractility and improve esophageal motor functions. However, the beneficial effects of these medications are limited and only confined to some specific drugs. Serotonergic agents, including buspirone, mosapride and prucalopride have been shown to improve parameters of esophageal motility although the effect on symptoms is less clear. Understanding on the complex correlation between esophageal hypomotility and esophageal symptoms as well as the limited evidence of prokinetic agents is necessary for physicians to appropriately manage patients with Ineffective Esophageal Motility (IEM).

Understanding the relationship between esophageal motor disorders and reflux disease

INTRODUCTION

The management of gastro-esophageal reflux disease (GERD) patients is often complex as the clinical presentation is heterogeneous and the mechanisms underlying symptoms are multifactorial. In the past decades, investigations conducted with conventional manometry and, above all, the more accurate high resolution manometry (HRM), helped us in exploring the field of esophageal motility and in understanding the link between motor features and GERD pathogenesis.

AREAS COVERED

Several studies carried out with conventional manometry and HRM have confirmed a relevant role of esophageal motor function in GERD pathogenesis. In particular, HRM studies have shown a direct correlation between impaired esophageal body motility, disruption of the esophagogastric junction and reflux burden. These findings impact the clinical and therapeutical management of GERD patients. Moreover, HRM findings might be helpful in evaluating patients with proton pump inhibitor (PPI) resistance and inconclusive evidences of GERD.

EXPERT OPINION

The relationship between esophageal motility and GERD pathogenesis needs to be further evaluated by multicenter outcome studies involving a large number of GERD patients and healthy controls. However, other more promising areas could be progressed.

Normal study or minor motor disorders detected on high-resolution oesophageal manometry - are they relevant?

Introduction

The clinical significance of normal motility or minor peristaltic disorders, noted on esophageal manometry, in symptomatic patients is unclear.

Aim

To determine the clinical presentation, response to treatment, and outcomes at 2-year follow-up in symptomatic patients with normal manometry and minor peristaltic disorders.

Material and methods

This prospective cohort study included patients between 18 and 80 years old. Patients with previous upper gastrointestinal surgery, prior dilation or myotomy, and major motility disorders or EGJ outflow obstruction as per CC v 3.0 were excluded. The cohort was divided into two groups: normal manometry (Gp1) and minor peristaltic defects (Gp2). Study subjects were contacted for follow-up at 6, 12, and 24 months from the date of initial high-resolution oesophageal manometry study. Details of drug use, symptom control, and requirement of anti-reflux procedures in both groups were obtained.

Results

Fifty-six patients (median age: 42.3 years, males 72%) formed the study cohort: Gp1 - 35 (62.5%) and Gp2 - 21 (37.5%). The patients in the two groups were comparable in terms of symptoms (p = 0.94) and treatment (p = 0.15) at presentation. On follow-up, the majority of the cases (76.8%) reported improvement in symptoms at 2 years. None required anti-reflux procedures. There were no significant differences in the symptom profile and drug use in patients in the two groups at various time periods.

Conclusions

Patients with normal and minor oesophageal motor function abnormalities do not worsen over time.

Ineffective esophageal motility: Concepts, future directions, and conclusions from the Stanford 2018 symposium

BACKGROUND

Ineffective esophageal motility (IEM) is a heterogenous minor motility disorder diagnosed when ≥50% ineffective peristaltic sequences (distal contractile integral <450 mm Hg cm s) coexist with normal lower esophageal sphincter relaxation (integrated relaxation pressure < upper limit of normal) on esophageal high-resolution manometry (HRM). Ineffective esophageal motility is not consistently related to disease states or symptoms and may be seen in asymptomatic healthy individuals.

PURPOSE

A 1-day symposium of esophageal experts reviewed existing literature on IEM, and this review represents the conclusions from the symposium. Severe IEM (>70% ineffective sequences) is associated with higher esophageal reflux burden, particularly while supine, but milder variants do not progress over time or consistently impact quality of life. Ineffective esophageal motility can be further characterized using provocative maneuvers during HRM, especially multiple rapid swallows, where augmentation of smooth muscle contraction defines contraction reserve. The presence of contraction reserve may predict better prognosis, lesser reflux burden and confidence in a standard fundoplication for surgical management of reflux. Other provocative maneuvers (solid swallows, standardized test meal, rapid drink challenge) are useful to characterize bolus transit in IEM. No effective pharmacotherapy exists, and current managements target symptoms and concurrent reflux. Novel testing modalities (baseline and mucosal impedance, functional lumen imaging probe) show promise in elucidating pathophysiology and stratifying IEM phenotypes. Specific prokinetic agents targeting esophageal smooth muscle need to be developed for precision management.

Frequent Sips of the Water for the Management of Gastroesophageal Reflux Induced Refractory Cough: A Case Report and Review of the Literature

BACKGROUND

Chronic cough is often associated with gastroesophageal reflux disease (GERD). The role of gastroenterologist in the management of the chronic cough is to identify and manage GERD. Ineffective esophageal motility is often associated with GERD induced cough. Chronic cough is often refractory to medical and surgical management despite adequate acid control. Unresponsiveness warrants a thorough pulmonary evaluation. The pathophysiology of refractory cough in these patients is poorly understood, and hence management is often challenging.

CASE PRESENTATION

A 75-year-old woman from Ghana was evaluated for GERD associated chronic cough. A 48-hour ambulatory pH study revealed acid exposure of 4.9% and high-resolution manometry showed decreased lower esophageal sphincter pressure, an inadequate response to medical and surgical management of GERD. Postfundoplication ambulatory pH testing demonstrated well-controlled acid reflux but her cough still persisted. Repeat manometry showed an ineffective motility disorder (IEM). Taking frequent sips of water eventually resolved her chronic cough.

CONCLUSION

Frequent sips of water can be used in the management of the gastroesophageal reflux and ineffective motility induced cough. It results in increased esophageal clearance of acid, nonacid reflux, and ingested pharyngeal secretions, thus breaking the cycle of cough generated increased intra-abdominal pressure with reflux and more cough.

Correlation Between Clinical Signs and High-resolution Manometry Data in Children

OBJECTIVES

High-resolution manometry (HRM) is the gold standard for diagnosis of esophageal motility disorders. However, clinical signs associated with these disorders are nonspecific, and it is difficult to correlate clinical signs with HRM data. The main objective of our study was to assess the positive predictive value (PPV) and negative predictive value (NPV) of each clinical sign, as well as their sensitivity and specificity in the diagnosis of esophageal motility disorders.

METHODS

This is a bicentric retrospective cohort study based on HRM data collected between May 2012 and May 2016. The studied symptoms were weight loss, feeding difficulties, swallowing disorders, dysphagia, food blockages, vomiting, gastroesophageal reflux disease (GERD), belching, and respiratory symptoms. HRM data were analyzed according to the Chicago Classification (3.0).

RESULTS

In total, 271 HRM data were analyzed, of which 90.4% showed abnormal results. HRM was well tolerated in 91% of the cases. The most common esophageal motility disorder was ineffective esophageal motility (38%). Weight loss was significantly associated (P = 0.003) with an abnormal HRM with a 96% PPV.

CONCLUSIONS

With nonspecific clinical signs suggesting an esophageal motility disorder, weight loss was a predictive sign of abnormal HRM results. HRM was well tolerated in pediatric patients, and ineffective esophageal motility appears to be the most frequent motility disorder in our cohort, as already observed in adult patient studies.

Role of Microbiota and Tryptophan Metabolites in the Remote Effect of Intestinal Inflammation on Brain and Depression

The human gastrointestinal tract is inhabited by trillions of commensal bacteria collectively known as the gut microbiota. Our recognition of the significance of the complex interaction between the microbiota, and its host has grown dramatically over the past years. A balanced microbial community is a key regulator of the immune response, and metabolism of dietary components, which in turn, modulates several brain processes impacting mood and behavior. Consequently, it is likely that disruptions within the composition of the microbiota would remotely affect the mental state of the host. Here, we discuss how intestinal bacteria and their metabolites can orchestrate gut-associated neuroimmune mechanisms that influence mood and behavior leading to depression. In particular, we focus on microbiota-triggered gut inflammation and its implications in shifting the tryptophan metabolism towards kynurenine biosynthesis while disrupting the serotonergic signaling. We further investigate the gaps to be bridged in this exciting field of research in order to clarify our understanding of the multifaceted crosstalk in the microbiota–gut–brain interphase, bringing about novel, microbiota-targeted therapeutics for mental illnesses.

A randomized double-blind placebo-controlled crossover-style trial of buspirone in functional dysphagia and ineffective esophageal motility

BACKGROUND

Studies suggest that Ineffective Esophageal Motility (IEM) is the manometric correlate of Functional Dysphagia (FD). Currently, there is no accepted therapy for either condition. Buspirone is a serotonin modulating medication and has been shown to augment esophageal peristaltic amplitude in healthy volunteers. We aimed to determine if buspirone improves manometric parameters and symptoms in patients with overlapping IEM/FD.

METHODS

We performed a prospective, double-blind, placebo-controlled, crossover-style trial of 10 patients with IEM/FD. The study consisted of two 2-week treatment arms with a 2-week washout period. Outcomes measured at baseline, end of week 2, and week 6 include high resolution esophageal manometry (HREM), the Mayo Dysphagia Questionnaire-14 (MDQ-14), and the GERD-HRQL.

RESULTS

The mean age of our 10 patients was 53 ± 9 years and 70% were female. After treatment with buspirone, 30% of patients had normalization of IEM on manometry; however, there was 30% normalization in the placebo group as well. Comparing buspirone to placebo, there was no statistically significant difference in the HREM parameters measured. There was also no statistically significant difference in symptom outcomes for buspirone compared to placebo. Of note, patients had a statistically significant decrease in the total GERD-HRQL total score when treated with placebo compared to baseline levels.

DISCUSSION

Despite previous data demonstrating improved esophageal motility in healthy volunteers, our study shows no difference in terms of HREM parameters or symptom scores in IEM/FD patients treated with buspirone compared to placebo. Further research is necessary to identify novel agents for this condition.

Spectrum of esophageal dysmotility in systemic sclerosis on high-resolution esophageal manometry as defined by Chicago classification

The classic manometric findings in systemic sclerosis are aperistalsis of the esophageal body with hypotensive lower esophageal sphincter. These changes contribute to gastroesophageal reflux disease in these patients. With widespread use of high-resolution esophageal manometry, diverse abnormalities are seen. The aim of this study is to characterize esophageal dysmotility in patients with systemic sclerosis undergoing high-resolution esophageal manometry and compare demographic features and diagnostic test results among patients with varying degrees of esophageal dysmotility. Patients with systemic sclerosis who underwent high-resolution esophageal manometry between January 2008 and October 2014 at our institution were identified. High-resolution esophageal manometry studies were reinterpreted using the Chicago Classification, v3.0 criteria. We also reviewed the patient charts for demographic data, indications for manometry, esophagogastroduodenoscopy findings, pH studies, medication use, and autoantibody panel. The cohort consisted of 122 patients with a mean age of 53.3 ± 15.3 years. High-resolution esophageal manometry was normal in 23, showed ineffective esophageal motility in 22, absent contractility in 73, and one case each of type II achalasia, esophagogastric junction outflow obstruction, hypercontractile esophagus, and distal esophageal spasm. Patients with absent contractility were younger and more likely to have erosive esophagitis, hiatal hernia, and esophageal strictures than patients with ineffective esophageal motility or normal manometry. There were no statistically significant differences in the groups based on autoantibodies or indications for manometry. Diverse esophageal motility abnormalities were noted in systemic sclerosis with ineffective esophageal motility or absent contractility observed in over three-fourth of the patients. Patients with absent contractility were younger and had more severe reflux. The severity of gastroesophageal reflux disease related endoscopic findings correlated with the degree of esophageal dysmotility on high-resolution esophageal manometry.

Understanding the Chicago Classification: From Tracings to Patients

Current parameters of the Chicago classification include assessment of the esophageal body (contraction vigour and peristalsis), lower esophageal sphincter relaxation pressure, and intra-bolus pressure pattern. Esophageal disorders include achalasia, esophagogastric junction outflow obstruction, major disorders of peristalsis, and minor disorders of peristalsis. Sub-classification of achalasia in types I, II, and III seems to be useful to predict outcomes and choose the optimal treatment approach. The real clinical significance of other new parameters and disorders is still under investigation.

Primary Esophageal Motility Disorders: Beyond Achalasia

The best-defined primary esophageal motor disorder is achalasia. However, symptoms such as dysphagia, regurgitation and chest pain can be caused by other esophageal motility disorders. The Chicago classification introduced new manometric parameters and better defined esophageal motility disorders. Motility disorders beyond achalasia with the current classification are: esophagogastric junction outflow obstruction, major disorders of peristalsis (distal esophageal spasm, hypercontractile esophagus, absent contractility) and minor disorders of peristalsis (ineffective esophageal motility, fragmented peristalsis). The aim of this study was to review the current diagnosis and management of esophageal motility disorders other than achalasia.

Neurotransmitters: The Critical Modulators Regulating Gut-Brain Axis

Neurotransmitters, including catecholamines and serotonin, play a crucial role in maintaining homeostasis in the human body. Studies on these neurotransmitters mainly revolved around their role in the "fight or flight" response, transmitting signals across a chemical synapse and modulating blood flow throughout the body. However, recent research has demonstrated that neurotransmitters can play a significant role in the gastrointestinal (GI) physiology. Norepinephrine (NE), epinephrine (E), dopamine (DA), and serotonin have recently been a topic of interest because of their roles in the gut physiology and their potential roles in GI and central nervous system pathophysiology. These neurotransmitters are able to regulate and control not only blood flow, but also affect gut motility, nutrient absorption, GI innate immune system, and the microbiome. Furthermore, in pathological states, such as inflammatory bowel disease (IBD) and Parkinson's disease, the levels of these neurotransmitters are dysregulated, therefore causing a variety of GI symptoms. Research in this field has shown that exogenous manipulation of catecholamine serum concentrations can help in decreasing symptomology and/or disease progression. In this review article, we discuss the current state-of-the-art research and literature regarding the role of neurotransmitters in regulation of normal GI physiology, their impact on several disease processes, and novel work focused on the use of exogenous hormones and/or psychotropic medications to improve disease symptomology. J. Cell. Physiol. 232: 2359-2372, 2017. © 2016 Wiley Periodicals, Inc.

Ineffective esophageal motility and the vagus: current challenges and future prospects

Ineffective esophageal motility (IEM) is characterized by low to very low amplitude propulsive contractions in the distal esophagus, hence primarily affecting the smooth muscle part of the esophagus. IEM is often found in patients with dysphagia or heartburn and is commonly associated with gastroesophageal reflux disease. IEM is assumed to be associated with ineffective bolus transport; however, this can be verified using impedance measurements or evaluation of a barium coated marshmallow swallow. Furthermore, water swallows may not assess accurately the motor capabilities of the esophagus, since contraction amplitude is strongly determined by the size and consistency of the bolus. The “peristaltic reserve” of the esophagus can be evaluated by multiple rapid swallows that, after a period of diglutative inhibition, normally give a powerful peristaltic contraction suggestive of the integrity of neural orchestration and smooth muscle action. The amplitude of contraction is determined by a balance between intrinsic excitatory cholinergic, inhibitory nitrergic, as well as postinhibition rebound excitatory output to the musculature. This is strongly influenced by vagal efferent motor neurons and this in turn is influenced by vagal afferent neurons that send bolus information to the solitary nucleus where programmed activation of the vagal motor neurons to the smooth muscle esophagus is initiated. Solitary nucleus activity is influenced by sensory activity from a large number of organs and various areas of the brain, including the hypothalamus and the cerebral cortex. This allows interaction between swallowing activities and respiratory and cardiac activities and allows the influence of acute and chronic emotional states on swallowing behavior. Interstitial cells of Cajal are part of the sensory units of vagal afferents, the intramuscular arrays, and they provide pacemaker activity to the musculature that can generate peristalsis in the absence of innervation. This indicates that a low-amplitude esophageal contraction, observed as IEM, can be caused by a multitude of factors, and therefore many pathways can be potentially explored to restore normal esophageal peristalsis.