Autonomic nerve function in adults with cyclic vomiting syndrome: a prospective study

Autonomic assessment at the intersection of psychosocial and gastrointestinal health

BACKGROUND

Wearable technology is increasingly used in clinical practice and research to monitor functional gastrointestinal symptoms and mental health.

AIMS

This article explores the potential of wearable sensors to enhance the understanding of the autonomic nervous system (ANS), particularly its role in linking psychological and gastrointestinal function. The ANS, facilitates brain-gut communication and is responsive to psychosocial conditions. It is implicated in disorders related to psychological stress and gut-brain interaction. Wearable technology enables tracking of the ANS in daily life, offering complementary and alternative methods from traditional lab-based measures. This review places focus on autonomic metrics such as respiratory sinus arrhythmia, vagal efficiency, and electrodermal activity as well as self-reports of autonomic symptoms.

DISCUSSION

Potential applications include use of wearable sensors for tracking autonomic activity in disorder of gut-brain interaction such as cyclic vomiting syndrome, in which ANS dysregulation may be triggered by psychosocial factors. Considerations for data interpretation and contextualization are addressed, acknowledging challenges such as situational confounders of ANS activity and accuracy of wearable devices.

Endocannabinoid signaling in stress, nausea, and vomiting

BACKGROUND

Classical antiemetics that target the serotonin system may not be effective in treating certain nausea and vomiting conditions like cyclic vomiting syndrome (CVS) and cannabinoid hyperemesis syndrome (CHS). As a result, there is a need for better therapies to manage the symptoms of these disorders, including nausea, vomiting, and anxiety. Cannabis is often used for its purported antiemetic and anxiolytic effects, given regulation of these processes by the endocannabinoid system (ECS). However, there is considerable evidence that cannabinoids can also produce nausea and vomiting and increase anxiety in certain instances, especially at higher doses. This paradoxical effect of cannabinoids on nausea, vomiting, and anxiety may be due to the dysregulation of the ECS, altering how it maintains these processes and contributing to the pathophysiology of CVS or CHS.

PURPOSE

The purpose of this review is to highlight the involvement of the ECS in the regulation of stress, nausea, and vomiting. We discuss how prolonged cannabis use, such as in the case of CHS or heightened stress, can dysregulate the ECS and affect its modulation of these functions. The review also examines the evidence for the roles of ECS and stress systems' dysfunction in CVS and CHS to better understand the underlying mechanisms of these conditions.

AGA Clinical Practice Update on Diagnosis and Management of Cyclic Vomiting Syndrome: Commentary

DESCRIPTION

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update (CPU) is to review the available evidence and provide expert advice regarding the diagnosis and management of cyclic vomiting syndrome.

METHODS

This CPU was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPUC and external peer review through standard procedures of Gastroenterology. This expert commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors who are experts in treating patients with cyclic vomiting syndrome.

Acute and Long-Term Effects of App-Delivered Heartfulness Meditation on Psychological Outcomes and the Endocannabinoid Signaling System in Cyclic Vomiting Syndrome

INTRODUCTION

Cyclic vomiting syndrome (CVS) is a disorder of gut-brain interaction often triggered by stress. Interventions such as meditation may improve psychological outcomes and health-related quality of life (HRQoL), but their efficacy and the underlying mechanism are unknown.

METHODS

We conducted a 6-week single-arm pilot study to assess the effects of heartfulness meditation (HFM) in CVS using a custom-designed meditation app. Primary outcomes included state and trait anxiety and mood state changes pre vs post-meditation, and secondary outcomes were psychological distress, coping, sleep quality, and HRQoL at baseline and at weeks 3 and 6. Serum concentrations of endocannabinoids N -arachidonylethanolamine and 2-arachidonoylglycerol and related lipids were measured pre- and post-HFM at baseline and week 6.

RESULTS

In 30 treatment completers, there was a significant improvement in state anxiety ( P < 0.001), total mood disturbance ( P < 0.001), and other mood states (all P values < 0.05) across the 3 time points. Trait anxiety was also improved at week 6. There was a significant improvement in psychological distress (Global Severity Index), sleep quality (daytime dysfunction), coping (using religion/spirituality), and HRQoL (mental and physical) across the 3 time points (all P < 0.05). Significant increases in N -arachidonylethanolamine and related lipids N -oleoylethanolamine and palmitoylethanolamide post vs pre-HFM were observed at week 6 ( P < 0.001, 0.002, 0.003, respectively). No adverse effects were noted.

DISCUSSION

App-delivered HFM is feasible, safe, and effective and improves psychological outcomes and augments endocannabinoids. This provides insight into the mechanism underlying HFM and has potential for widespread use as a digital therapeutic in CVS and other disorder of gut-brain interaction.

Cyclic vomiting syndrome: From pathophysiology to treatment

Cyclic vomiting syndrome (CVS) is a disorder characterized by recurrent and unpredictable episodes of intense vomiting, interspersed with periods of apparent wellbeing. This disorder, which primarily affects children and adolescents but can persist into adulthood, has recently been the subject of extensive study and analysis in the medical literature. The aim of the present review is to examine the most important aspects of the epidemiology, pathophysiology, subtypes, diagnostic criteria, and current management of CVS. Even though the exact etiology remains unknown, genetic factors (polymorphisms), nervous system alterations and autonomic dysregulation, and environmental factors (use and abuse of cannabinoids) are postulated as possible triggers. CVS has significant diagnostic challenges, given that there is no specific test for confirming its presence. Thorough evaluation of symptoms and the ruling out of other possible causes of recurrent vomiting are required. Management of CVS typically involves a multidisciplinary approach. Pharmacologic options are explored, such as antiemetics and preventive medications, as well as behavioral and psychologic support therapies. Treatment personalization is essential, adapting it to the individual needs of each patient. Despite advances in the understanding of CVS, it remains a significant clinical challenge. This disorder impacts the quality of life of those affected and their families, underscoring the ongoing need for research and the development of more effective treatment strategies.

Cyclic vomiting syndrome: Future clinical and research priorities for: Special supplement/proceedings of 3rd international symposium

BACKGROUND

An increasing number of studies have explored the clinical features, epidemiology, pathophysiology, and management of cyclic vomiting syndrome (CVS). CVS is common in adults and children and negatively impacts patients, families, and the healthcare system. A related condition, cannabinoid hyperemesis syndrome (CHS), has been a focus of interest in the lay press and published literature.

PURPOSE

Clinical presentations of CVS have been defined by small series and expert opinion, but recent prospective studies are refining our understanding of the spectrum of emetic episodes and the breadth of comorbid conditions. Large cross-sectional population analyses are clarifying CVS prevalence and factors related to age, ethnicity, and geographic region. CVS pathophysiology is multifactorial with contributions from migraines, dysautonomia, endogenous cannabinoids, mitochondrial dysfunction, genetic abnormalities, and rapid gastric emptying. CVS treatment relies on antiemetics and antimigraine therapies to abort acute episodes coupled with prophylactic regimens employing neuromodulators and antiepileptics. CHS represents a challenge partly because of difficulties in achieving sustained cannabis abstinence. Benefits of other therapies in CHS remain poorly defined. Several areas warrant further scrutiny including better identification of CVS triggers and characterization of different CVS subsets including those with frequent severe episodes, refined description of epidemiology to allow targeting of populations predisposed to CVS development, rigorous definition of pathogenic factors to provide a foundation for exploratory studies of novel therapies, and conduct of controlled trials by multicenter collaborations to confirm benefits of existing and new therapies in development. Progress in these areas will be facilitated by generous governmental and industry support.

Plasma endocannabinoids and cannabimimetic fatty acid derivatives are altered in cyclic vomiting syndrome: The effects of sham feeding

Cyclic vomiting syndrome (CVS) is an underdiagnosed disorder of the gut-brain interaction. Our understanding of the pathophysiology of CVS is evolving. Here, we tested the hypotheses that: (1) the levels of endocannabinoids and related lipids are altered in CVS, and (2) cephalic-vagal stimulation drive changes in endolipid levels. Ten adult patients with CVS and eight healthy controls were included. Indirect measurements of parasympathetic (RFa) functions were performed with spectral analysis of heart rate variability and respiratory activity. Plasma levels of endocannabinoids and related lipids were measured at baseline and during a sham feeding. Values are reported as mean ± standard error of the mean and compared using t-test or ANOVA. CVS patients had a lower parasympathetic tone and response to the Valsalva maneuver and deep breathing than the controls. The baseline 2-Arachidonoylglycerol (2-AG) had a significantly higher concentration in CVS (5.9e-008 ± 3.7e-008 mol/L) than control (3.7e-008 ± 1.3e-008 mol/; p < 0.05). Sham feeding did not change the concentration of 2-AG. 2-oleoylglycerol (2-OG) was significantly higher in CVS than control and did not change with sham feeding. Levels of N-acylethanolamines, including anandamide (AEA), were not different in CVS vs control. After sham feeding, AEA showed a trend toward increasing (p = 0.08) in CVS, but not in control. With sham feeding, palmitoyl ethanolamine significantly increased in both CVS and control groups; oleoyl ethanolamine in CVS only, and stearoyl ethanolamine in the control group. Levels of endocannabinoids and related lipids are altered in CVS patients. Sham feeding affects endogenous signaling lipids in a disease and time-dependent manner.

Percutaneous electrical nerve field stimulation improves comorbidities in children with cyclic vomiting syndrome

Introduction

Children with cyclic vomiting syndrome (CVS) frequently suffer from disabling abdominal pain and comorbidities that impair quality of life. A noninvasive, auricular percutaneous electrical nerve field stimulation (PENFS) device is shown to be effective for abdominal pain in children with disorders of gut-brain interaction. We aimed to determine the effects of PENFS on pain, common comorbidities, and quality of life in pediatric CVS.

Methods

Children aged 8-18 years with drug-refractory CVS were enrolled in a prospective, open-label study receiving 6 consecutive weeks of PENFS. Subjects completed the following surveys at baseline, during/after therapy (week 6), and at extended follow-up approximately 4-6 months later: Abdominal Pain Index (API), State-Trait Anxiety Inventory for Children (STAI-C), Pittsburgh Sleep Quality Index (PSQI), and Patient Reported Outcome Measurement Information System (PROMIS) Pediatric Profile-37.

Results

Thirty subjects were included. Median (interquartile range, IQR) age was 10.5 (8.5-15.5) years; 60% were female. Median API scores decreased from baseline to week 6 (p = 0.003) and to extended follow-up (p < 0.0001). State anxiety scores decreased from baseline to week 6 (p < 0.0001) and to extended follow-up (p < 0.0001). There were short-term improvements in sleep at 6 weeks (p = 0.031) but not at extended follow-up (p = 0.22). Quality of life measures of physical function, anxiety, fatigue, and pain interference improved short-term, while there were long-term benefits for anxiety. No serious side effects were reported.

Conclusions

This is the first study to demonstrate the efficacy of auricular neurostimulation using PENFS for pain and several disabling comorbidities in pediatric CVS. PENFS improves anxiety, sleep, and several aspects of quality of life with long-term benefits for anxiety.Clinical trial registration: ClinicalTrials.gov, identifier NCT03434652.

Natural History of Pediatric Cyclic Vomiting Syndrome: Progression to Dysautonomia

BACKGROUND

The clinical features of pediatric cyclic vomiting syndrome (CVS) often evolve over time. Many patients develop a constellation of chronic symptoms that suggest autonomic nervous system (ANS) dysfunction during adolescence. We aimed to determine the proportion of children with CVS who develop chronic rather than episodic symptoms consistent with ANS dysfunction.

METHODS

Retrospective chart review of children ages 0-18 years followed in an outpatient tertiary care CVS center. Patients completed standardized questionnaires at intake and follow-up visits, documenting clinical symptom pattern. Continuous variables are summarized as median [interquartile range (IQR)]. A Mann-Whitney test was used for group comparisons.

RESULTS

One hundred subjects were included. A total of 40% developed symptoms of ANS dysfunction (ANS+); 20% were confirmed by comprehensive ANS testing, 11% by orthostatic vital sign abnormalities, and 9% by clinical symptoms. The median (IQR) age at onset of chronic symptoms was 14 (10.02, 15) years. The presence of another disorder of gut-brain interaction ( P = 0.018) and a greater number of comorbidities ( P = 0.031) were more common in the ANS+ group. ANS+ subjects missed more school days ( P = 0.047) and were seen less frequently in the emergency department ( P = 0.023).

CONCLUSIONS

Many children with CVS (40%) develop symptoms consistent with clinical dysautonomia in adolescence. These patients experience more comorbid conditions and a greater impact on school attendance, possibly representing a worsened quality of life as their disease course transitions to daily symptoms. When symptoms of CVS change over time, therapeutic interventions may need to be adjusted and targeted accordingly.

Cyclic Vomiting Syndrome and Cannabis Hyperemesis Syndrome: The State of the Science

This article provides a narrative review of the state of the science for both cyclic vomiting syndrome and cannabis hyperemesis syndrome along with a discussion of the relationship between these 2 conditions. The scope of this review includes the historical context of these conditions as well as the prevalence, diagnostic criteria, pathogenesis, and treatment strategies for both conditions. A synopsis of the endocannabinoid system provides a basis for the hypothesis that a lack of cannabidiol in modern high-potency Δ 9 -tetrahydrocannabinol cannabis may be contributory to cannabis hyperemesis syndrome and possibly other cannabis use disorders. In concluding assessment, though the publications addressing both adult cyclic vomiting syndrome and cannabis hyperemesis syndrome are steadily increasing overall, the state of the science supporting the treatments, prognosis, etiology, and confounding factors (including cannabis use) is of moderate quality. Much of the literature portrays these conditions separately and as such sometimes fails to account for the confounding of adult cyclic vomiting syndrome with cannabis hyperemesis syndrome. The diagnostic and therapeutic approaches are, at present, based generally on case series publications and expert opinion, with a very limited number of randomized controlled trials and a complete absence of Level 1 evidence within the cyclic vomiting literature overall as well as for cannabis hyperemesis syndrome specifically.

Diagnosis and Management of Cyclic Vomiting Syndrome: A Critical Review

Cyclic vomiting syndrome (CVS) is a chronic disorder of gut-brain interaction characterized by recurrent disabling episodes of nausea, vomiting, and abdominal pain. CVS affects both children and adults with a prevalence of approximately 2% in the United States. CVS is more common in female individuals and affects all races. The pathophysiology of CVS is unknown and a combination of genetic, environmental, autonomic, and neurohormonal factors is believed to play a role. CVS is also closely associated with migraine headaches and likely have a shared pathophysiology. The diagnosis of CVS is based on the Rome criteria, and minimal recommended testing includes an upper endoscopy and imaging studies of the abdomen. CVS is frequently associated with anxiety, depression, and autonomic dysfunction. Patients with CVS commonly use cannabis therapeutically for symptom relief. By contrast, cannabinoid hyperemesis syndrome is believed to be a subset of CVS with chronic heavy cannabis use leading to hyperemesis. Due to the recalcitrant nature of the illness, patients often visit the emergency department and are hospitalized for acute CVS flares. Guidelines on the management of CVS recommend a biopsychosocial approach. Prophylactic therapy consists of tricyclic antidepressants (amitriptyline), antiepileptics (topiramate), and aprepitant in refractory patients. Abortive therapy consists of triptans, antiemetics (ondansetron), and sedation. Treatment of comorbid conditions is extremely important to improve overall patient outcomes. CVS has a significant negative impact on patients, families, and the healthcare system, and future research to understand its pathophysiology and develop targeted therapies is needed.

Cardiac Vagal Regulation Is Impeded in Children With Cyclic Vomiting Syndrome

INTRODUCTION

The pathophysiology underlying cyclic vomiting syndrome (CVS) remains undefined. Scant data and distinct clinical features point to altered autonomic nervous system function. Autonomic signaling can be noninvasively assessed through cardiac indices of parasympathetic vagal regulation, which is reduced in children with disorders of gut-brain interaction. We aimed to examine dynamic cardiac vagal regulation in children with CVS compared with that in healthy controls (HC).

METHODS

A total of 31 children with CVS evaluated in a tertiary care CVS center and 66 HC (ages 8-18 years) underwent cardiac autonomic function assessment. Electrocardiogram recordings were conducted during 3-minute sit/stand/sit posture challenges. The electrocardiogram-derived variables heart period, respiratory sinus arrhythmia (RSA), and vagal efficiency (VE) were analyzed using linear regression and mixed-effects modeling.

RESULTS

After exclusion of medication confounders, 23 patients with CVS were included in analyses. Both groups were comparable in age, gender, and body mass index. Compared with HC, children with CVS had shorter heart period (standardized mean difference range: 1.15-1.22, all P values < 0.05) and lower RSA (SMD range: 0.66-0.88, all P values < 0.05). Patients with CVS had significantly lower VE during the entire course of posture shifts, compared with HC ( B = -19.87, SE = 6.95, t = -2.86, P = 0.005, SMD = 0.76).

DISCUSSION

Children with CVS have suboptimal parasympathetic autonomic regulation compared with HC, indexed by reduced RSA and VE, even during their interepisodic well phase. Abnormal vagal modulation may underlie CVS pathophysiology, comorbidities, and triggers. Assessing VE during posture stressors could inform therapeutic interventions.

Abdominal migraine and cyclical vomiting syndrome

Abdominal migraine and cyclical vomiting syndrome (CVS) are characteristic syndromes which have overlapping characteristics with migraine but lack the cardinal symptom of headache. Both abdominal migraine and CVS are characterized by recurrent attacks of nausea, vomiting, and/or abdominal pain lasting hours to a few days, with symptom freedom between attacks. Both abdominal migraine and CVS typically occur in children and adolescents, who often go on to develop more typical migraine headaches when older, but may also present for the first time in adults. Due to their shared characteristics and association with migraine headaches, abdominal migraine and CVS are sometimes called "migraine equivalents," and their pathophysiology is assumed to overlap with migraine headache. This chapter describes what is known about the clinical characteristics, epidemiology, pathophysiology, and prognosis of abdominal migraine and CVS, and explores their relationship to migraine. We also review the existing evidence for the nonpharmacological management, acute treatment of attacks, and preventive treatments for both abdominal migraine and CVS.

Current understanding of the etiology of cyclic vomiting syndrome and therapeutic strategies in its management

INTRODUCTION

Cyclic vomiting syndrome is a chronic debilitating disorder of the gut-brain interaction and is characterized by recurrent episodes of nausea and vomiting.Recent studies indicate that it is common and affects 2% of the US population. Unfortunately, there is significant heterogeneity in the management of these patients in the medical community. This review article aims to bridge this gap and will review the epidemiology and etiology with a focus on management of CVS.

AREAS COVERED

This article reviews the epidemiology, and pathophysiology of CVS and impact on patients. It also discusses management based on recent guidelines based on which is intended for the busy clinician. A literature search was done using PubMed and key words "cyclic vomiting", "management", "etiology", and pathophysiology were used to identify articles of importance.

EXPERT OPINION

CVS is a complex, poorly understood disorder of gut-brain interaction (DGBI) and has a significant negative impact on patients, families and the healthcare system. Recent guidelines recommend a multidisciplinary approach to management using prophylactic therapy in moderate-severe CVS and abortive medication for acute flares. However more research is needed to better understand the pathophysiology and develop targeted therapies for CVS.

Adult acetonemic vomiting complicated with low body weight in a subject with Mycobacterium avium complex pulmonary disease: a case report

Pulmonary diseases often cause significant health issues and nutritional disorders. Weight loss and malnutrition are related to the severity of obstructive disorders. Therefore, patients with such conditions often experience low nutritional energy. Acetonemic vomiting is caused by acetonemic syndrome. Previously, it was believe that acetonemic vomiting was observed only in childhood. However, it was recently suggested that acetonemic vomiting can also occur in adults. It is also considered that acetonemic vomiting can occur in subjects with low body weight because stored carbohydrate levels are reduced and fats are mainly used for energy. Consequently, large amounts of acetone are produced, ultimately resulting in nausea and vomiting. In this study, we report a case of adult acetonemic vomiting complicated by low body weight in a subject with Mycobacterium avium complex pulmonary disease.

Cyclic Vomiting Syndrome-Related Hospitalizations Trends, Comorbidities & Health Care Costs in Children: A Population Based Study

AIM

To analyze the clinical characteristics, trends in hospitalization and health care resource utilization of pediatric patients with cyclical vomiting syndrome (CVS).

METHODS

We analyzed the latest 5 Healthcare Cost and Utilization Project-Kids Inpatient Database (HCUP-KID) datasets including years 2003, 2006, 2009, 2012 and 2016 for patients aged 1-20 years with a primary diagnosis of CVS and were compared with Age/gender-matched controls for comorbidities, clinical outcomes, and healthcare resource utilization.

RESULTS

A total of 12,396 CVS-related hospitalizations were analyzed. The mean age of CVS patients was 10.4 ± 6.7 years. CVS was associated with dysautonomia (OR: 12.1; CI: 7.0 to 20.8), dyspepsia (OR: 11.9; CI: 8.8 to 16.03), gastroesophageal reflux disease (OR: 6.9; Confidence Interval (CI): 6.4 to 7.5), migraine headaches (OR: 6.8; CI: 5.9 to 7.7) and irritable bowel syndrome (OR: 2.08; CI: 1.2 to 4.3) (all p < 0.001). CVS was also associated with increased cannabis use (OR: 5.26, 4.6 to 5.9; p < 0.001), anxiety disorder (OR: 3.9; CI: 3.5 to 4.4) and stress reaction (OR: 3.6; CI: 2.06 to 6.3), p < 0.001. Mean CVS-related hospitalization costs (inflation adjusted) more than doubled from $3199 in 2003 to $6721 in 2016, incurring $84 million/year in total costs.

CONCLUSION

Hospitalized CVS patients have increased prevalence of DGBIs, dysautonomia, psychiatric conditions and cannabis use compared to non-CVS controls. CVS-related hospitalizations in U.S. is associated with increasing health care costs. Better management of CVS and comorbid conditions is warranted to reduce health care costs and improve outcomes.

Greater intolerance to uncertainty predicts poorer quality of life in adults with cyclic vomiting syndrome

BACKGROUND

Cyclic vomiting syndrome (CVS) is an idiopathic disorder of gut-brain interaction characterized by recurrent bouts of nausea and vomiting. Although CVS negatively impacts quality of life (QOL), the determinants of impaired QOL among adult CVS sufferers are not fully understood. The unpredictability of CVS attacks may generate anticipatory anxiety and worsen quality of life in a substantial proportion of patients with CVS. Intolerance to uncertainty (IU) is a cognitive trait in which individuals experience distress when faced with unpredictable situations, particularly those with potentially negative consequences. Higher trait IU is a well-established vulnerability factor linked to the development of multiple psychiatric conditions, including anxiety. However, the extent to which higher IU is associated with impaired QOL in adults with CVS is not known.

METHODS

To explore this issue, we surveyed 118 adult CVS patients and obtained demographic information, clinical features, reported healthcare utilization, and standardized assessments of IU, anxiety and panic, and QOL.

KEY RESULTS

Adult CVS patients with higher IU did not report a greater frequency of CVS attacks or overall CVS-related healthcare utilization than those with lower IU. Yet, this group demonstrated substantially poorer physical and mental health-related QOL and higher rates of anxiety-spectrum disorders.

CONCLUSIONS & INFERENCES

Higher degrees of IU are associated with increased anxiety and reduced QOL in patients with CVS. IU is a malleable cognitive trait that can be targeted by cognitive behavioral therapy (CBT). Our results suggest that some CVS patients may benefit from non-pharmacologic therapies such as CBT.

Cannabinoid Hyperemesis Syndrome in Pediatrics: An Emerging Problem

Cannabis use has been evolving in both recreational drug use and medicinal uses, in part due to the recent introduction of various strains and components. With increasing use, we have seen emergence of a hyperemesis syndrome called cannabinoid hyperemesis syndrome characterized as intractable vomiting, nausea, and abdominal pain in the context of prolonged cannabinoid use. Although the antiemetic properties of cannabis have been known for years, the paradoxical effect of hyperemesis has yet to be elucidated. Herein we discuss the current research, epidemiology, and diagnosis and treatment of cannabinoid hyperemesis syndrome. Without timely diagnosis and treatment, patients may experience significant physical and emotional distress, as well as place unnecessary financial burden on the medical system.

Predictors of Hospital Admission for Pediatric Cyclic Vomiting Syndrome

OBJECTIVES

To identify predictors of hospitalization in pediatric patients presenting to an emergency department (ED) for a cyclic vomiting syndrome (CVS) attack.

STUDY DESIGN

We retrospectively reviewed patients with CVS seen at our institution between 2015 and 2018 and included those who met the Rome IV criteria for CVS. We identified all CVS-related ED visits and subsequently performed a case-control analysis, utilizing multivariate logistic regression, to identify clinical and demographic factors that may predict hospitalization.

RESULTS

In total, 219 patients with CVS (using International Statistical Classification of Diseases and Related Health Problems, 10th Revision) were identified, of which 65% met the inclusion criteria (median age 11 years). We identified 152 CVS-related ED visits, of which 62% resulted in hospitalization. Factors found to predict hospitalization using multivariate analyses included male sex (P = .04), younger age (P = .027), delayed presentation (>24 hours) to the ED (P < .001), and longer wait time prior treatment with antiemetics (P = .029).

CONCLUSION

One-quarter of all patients with CVS had presented to the ED and nearly two-thirds of these ED visits resulted in hospitalization. A delayed presentation to the ED following the onset of symptoms was the strongest independent predictor of hospital admission, alongside male sex, younger age, and longer ED wait times before treatment with antiemetics. These findings suggest that early intervention may be key to successfully mitigating the risk of hospitalization for a CVS attack.

Ketamine in Refractory Cyclic Vomiting Syndrome: A Case Report and Review of Literature

PURPOSE

To describe the use of ketamine in an adult patient in aborting a cyclic vomiting syndrome (CVS) episode.

SUMMARY

A 40-year-old man with a history of CVS was admitted after several days of nausea and vomiting. He was given parenteral doses of lorazepam and ondansetron but was unable to remain emesis-free. Ketamine was recommended by Gastroenterology as a therapeutic option after exhausting all first- and second-line agents. Ketamine is a noncompetitive N-methyl-D-aspartate receptor antagonist that is widely used for its analgesic and sedative effects. While there is some data to support its use in CVS, most of the published literature has been limited to the Emergency Department setting and no specific therapeutic dose has been established. We will review our institution's experience with low dose ketamine in an adult patient with a CVS episode that is refractory to first-line agents.

CONCLUSION

In the case described, ketamine at a low sub-anesthetic dose successfully aborted a CVS episode with no appreciable side effects. As much of ketamine's full effects remain relatively unknown, additional studies are needed to determine optimal strategies for ketamine use in patients with a CVS episode.

A link between gastrointestinal disorders and migraine: Insights into the gut-brain connection

Background

Migraine is a complex, multifaceted, and disabling headache disease that is often complicated by gastrointestinal (GI) conditions, such as gastroparesis, functional dyspepsia, and cyclic vomiting syndrome (CVS). Functional dyspepsia and CVS are part of a spectrum of disorders newly classified as disorders of gut–brain interaction (DGBI). Gastroparesis and functional dyspepsia are both associated with delayed gastric emptying, while nausea and vomiting are prominent in CVS, which are also symptoms that commonly occur with migraine attacks. Furthermore, these gastric disorders are comorbidities frequently reported by patients with migraine. While very few studies assessing GI disorders in patients with migraine have been performed, they do demonstrate a physiological link between these conditions.

Objective

To summarize the available studies supporting a link between GI comorbidities and migraine, including historical and current scientific evidence, as well as provide evidence that symptoms of GI disorders are also observed outside of migraine attacks during the interictal period. Additionally, the importance of route of administration and formulation of migraine therapies for patients with GI symptoms will be discussed.

Methods

A literature search of PubMed for articles relating to the relationship between the gut and the brain with no restriction on the publication year was performed. Studies providing scientific support for associations of gastroparesis, functional dyspepsia, and CVS with migraine and the impact these associations may have on migraine treatment were the primary focus. This is a narrative review of identified studies.

Results

Although the association between migraine and GI disorders has received very little attention in the literature, the existing evidence suggests that they may share a common etiology. In particular, the relationship between migraine, gastric motility, and vomiting has important clinical implications in the treatment of migraine, as delayed gastric emptying and vomiting may affect oral dosing compliance, and thus, the absorption and efficacy of oral migraine treatments.

Conclusions

There is evidence of a link between migraine and GI comorbidities, including those under the DGBI classification. Many patients do not find adequate relief with oral migraine therapies, which further necessitates increased recognition of GI disorders in patients with migraine by the headache community.

Cyclic vomiting syndrome: A narrative review and guide to management

OBJECTIVES/BACKGROUND

Cyclic vomiting syndrome (CVS) is a disabling disorder of gut-brain interaction manifested by stereotypical and severe episodes of nausea and vomiting. Prevalence data indicate that CVS affects 1-2% of children and there has been a recent dramatic rise in diagnosed adults.

METHODS

This narrative review summarizes relevant literature pertaining to pediatric and adult CVS and provides a guide to management based on extensive clinical experience.

RESULTS

More timely diagnosis is facilitated by an expert consensus diagnostic approach and limited testing. Some diagnostic tests of exclusion remain essential. These include an upper gastrointestinal (GI) contrast study to exclude intestinal malrotation and basic laboratory screening. An abdominal ultrasound is recommended to exclude renal hydronephrosis in children and biliary disease in adults. Exclusion of metabolic/genetic conditions is warranted in those with specific warning signs, presentation in infants/toddler age, and in those with refractory disease. In the absence of chronic GI symptoms, referral to a GI specialist for upper endoscopy is generally not necessary in children but recommended in adults. A large subset termed migraine-equivalent CVS display strong clinical and genetic features of migraine. A unifying pathophysiologic core concept involves neuronal hyperexcitability and aberrant central modulation of autonomic signals. This is coupled with multiple susceptibility factors including mitochondrial dysfunction/cellular energy deficits, a hyper-responsive hypothalamic-pituitary-adrenal axis and many comorbidities that increase vulnerability to triggering events. CVS episodes are frequently triggered by stressors and intercurrent illnesses. Lifestyle and non-pharmacological interventions thus play a pivotal role in successful management. Pharmacological therapies are categorized into abortive, supportive/rescue, and prophylactic treatments. The majority respond particularly well to migraine-focused treatment strategies.

CONCLUSION

Despite improved characterization and understanding, CVS remains classified as a functional disorder of brain-gut interaction that is often disjointly managed by generalists and subspecialists. Early recognition, evaluation, and management will facilitate care and improve outcomes. Further research into its natural history with common progression to migraine headaches, neuroendocrine mechanisms, and the pathophysiologic relation to migraine diathesis is much needed.

Cyclic Vomiting Syndrome in Children

Cyclic Vomiting Syndrome (CVS) is an underdiagnosed episodic syndrome characterized by frequent hospitalizations, multiple comorbidities, and poor quality of life. It is often misdiagnosed due to the unappreciated pattern of recurrence and lack of confirmatory testing. CVS mainly occurs in pre-school or early school-age, but infants and elderly onset have been also described. The etiopathogenesis is largely unknown, but it is likely to be multifactorial. Recent evidence suggests that aberrant brain-gut pathways, mitochondrial enzymopathies, gastrointestinal motility disorders, calcium channel abnormalities, and hyperactivity of the hypothalamic-pituitary-adrenal axis in response to a triggering environmental stimulus are involved. CVS is characterized by acute, stereotyped and recurrent episodes of intense nausea and incoercible vomiting with predictable periodicity and return to baseline health between episodes. A distinction with other differential diagnoses is a challenge for clinicians. Although extensive and invasive investigations should be avoided, baseline testing toward identifying organic causes is recommended in all children with CVS. The management of CVS requires an individually tailored therapy. Management of acute phase is mainly based on supportive and symptomatic care. Early intervention with abortive agents during the brief prodromal phase can be used to attempt to terminate the attack. During the interictal period, non-pharmacologic measures as lifestyle changes and the use of reassurance and anticipatory guidance seem to be effective as a preventive treatment. The indication for prophylactic pharmacotherapy depends on attack intensity and severity, the impairment of the QoL and if attack treatments are ineffective or cause side effects. When children remain refractory to acute or prophylactic treatment, or the episode differs from previous ones, the clinician should consider the possibility of an underlying disease and further mono- or combination therapy and psychotherapy can be guided by accompanying comorbidities and specific sub-phenotype. This review was developed by a joint task force of the Italian Society of Pediatric Gastroenterology Hepatology and Nutrition (SIGENP) and Italian Society of Pediatric Neurology (SINP) to identify relevant current issues and to propose future research directions on pediatric CVS.

Autonomic function in gastroparesis and chronic unexplained nausea and vomiting: Relationship with etiology, gastric emptying, and symptom severity

BACKGROUND

Autonomic dysfunction can be present in patients with idiopathic and diabetic gastroparesis. The role of autonomic dysfunction relating to gastric emptying and upper gastrointestinal symptoms in patients with gastroparesis and chronic unexplained nausea and vomiting (CUNV) remains unclear. The aim of our study is to evaluate autonomic function in patients with gastroparesis and CUNV with respect to etiology, gastric emptying and symptom severity.

METHODS

We studied 242 patients with chronic gastroparetic symptoms recruited at eight centers. All patients had a gastric emptying scintigraphy within 6 months of the study. Symptom severity was assessed using the gastroparesis cardinal symptom index. Autonomic function testing was performed at baseline enrollment using the ANX 3.0 autonomic monitoring system which measures heart rate variability and respiratory activity measurements.

KEY RESULTS

Low sympathetic response to challenge (Valsalva or standing) was the most common abnormality seen impacting 89% diabetic and 74% idiopathic patients. Diabetics compared to idiopathics, exhibited greater global hypofunction with sympathetic (OR = 4.7, 95% CI 2.2-10.3; P < .001) and parasympathetic (OR = 7.2, 95% CI 3.4-15.0; P < .001) dysfunction. Patients with delayed gastric emptying were more likely to have paradoxic parasympathetic excessive during sympathetic challenge [(Valsalva or standing) 40% vs. 26%, P = .05]. Patients with more severe symptoms exhibited greater parasympathetic dysfunction compared to those with mild-moderate symptoms: resting sympathovagal balance [LFa/RFa 1.8 (1.0-3.1) vs. 1.2 (0.6-2.3), P = .006)] and standing parasympathetic activity [0.4 (0.1-0.8) vs. 0.6 (0.2-1.7); P = .03].

CONCLUSIONS

Autonomic dysfunction was common in patients with gastroparesis and CUNV. Parasympathetic dysfunction was associated with delayed gastric emptying and more severe upper gastrointestinal symptoms. Conversely, sympathetic hypofunction was associated with milder symptoms.

INFERENCES

Gastroparesis and CUNV may be a manifestation of GI autonomic dysfunction or imbalance, such that sympathetic dysfunction occurs early on in the manifestation of chronic upper GI symptoms, while parasympathetic dysfunction results in more severe symptoms and delayed gastric emptying.

Neurological Etiologies and Pathophysiology of Cyclic Vomiting Syndrome

Cyclic vomiting syndrome is an idiopathic chronic periodic disorder of childhood which may persist into the adult years. Although cyclic vomiting syndrome is considered a central nervous system disorder, it is often managed by a pediatric gastroenterologist. The practitioner should not assume a gastrointestinal or non-neurological cause of symptoms especially if there are coexisting neurological symptoms and signs or if vomiting does not bring relief; this suggests a possible central nervous system cause, which may necessitate a pediatric neurology consultation. Examples of central nervous system causes of cyclic vomiting syndrome that can have subjective and objective neurological findings include abdominal migraine, certain types of epilepsy, structural lesions (tumors, Chiari malformation, demyelinating disease), mitochondrial disease, autonomic disorders, fatty acid/organic acid disorders, urea cycle defects, and cannabinoid hyperemesis syndrome. Improved familiarity with cyclic vomiting syndrome and its mimics may improve the time to appropriate diagnosis and may reduce morbidity related to cyclic vomiting syndrome.

Cyclic vomiting syndrome: an overview for clinicians

Introduction: Cyclic vomiting syndrome (CVS) is an under recognized entity causing significant impact on patient's lifestyle. CVS is characterized by recurrent episodes of abdominal pain, nausea, and vomiting leading to many emergency department presentations prior to diagnosis. Patients often have lengthy delays in starting appropriate therapy leading to significant physical and financial hardship. Most cases of cyclic vomiting syndrome are reversible by managing risk factors and starting on appropriate treatment.Areas covered: This review covers the diagnostic criteria, pathophysiology, risk factors, and treatment for CVS and provides a valuable resource for clinicians to review and help with managing this challenging syndrome. The latest literature regarding the diagnosis and management of CVS is summarized.Expert Opinion: The direction for future research in CVS and insights to managing CVS are summarized. The role of pain that can be frequently controlled by tricyclic antidepressants and lorazepam suggests a central nervous system (CNS) origin. A standardized treatment regimen for CVS must be implemented as patients do respond to current therapies but there is often a significant delay in initiation of treatment. Reviewed recent data looking at MRI brain changes in patients with CVS that may lead to a better understanding of the pathophysiology of this disease.

Guidelines on management of cyclic vomiting syndrome in adults by the American Neurogastroenterology and Motility Society and the Cyclic Vomiting Syndrome Association

The increasing recognition of cyclic vomiting syndrome (CVS) in adults prompted the development of these evidence-based guidelines on the management of CVS in adults, which was sponsored by the American Neurogastroenterology and Motility Society (ANMS) and the Cyclic Vomiting Syndrome Association (CVSA). GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) framework was used and a professional librarian performed the literature search. The expert committee included the President of the CVSA who brought a patient perspective into the deliberations. The committee makes recommendations for the prophylaxis of CVS, treatment of acute attacks, diagnosis, and overall management of CVS. The committee strongly  recommends that adults with moderate-to-severe CVS receive a tricyclic antidepressant (TCA), such as amitriptyline, as a first-line prophylactic medication and receive topiramate or aprepitant as alternate prophylactic medications. Zonisamide or levetiracetam and mitochondrial supplements (Coenzyme Q10, L-carnitine, and riboflavin) are conditionally recommended as alternate prophylactic medications, either alone or concurrently with other prophylactic medications. For acute attacks, the committee conditionally recommends using serotonin antagonists, such as ondansetron, and/or triptans, such as sumatriptan or aprepitant to abort symptoms. Emergency department treatment is best achieved with the use of an individualized treatment protocol and shared with the care team (example provided). The committee recommended screening and treatment for comorbid conditions such as anxiety, depression, migraine headache, autonomic dysfunction, sleep disorders, and substance use with referral to appropriate allied health services as indicated. Techniques like meditation, relaxation, and biofeedback may be offered as complementary therapy to improve overall well-being and patient care outcomes.

Epidemiology, Clinical Characteristics, and Associations for Rome IV Functional Nausea and Vomiting Disorders in Adults

BACKGROUND & AIMS

Functional nausea and vomiting disorders (FNVDs) are classified as chronic nausea and vomiting syndrome (CNVS) or cyclic vomiting syndrome (CVS)-CVS includes cannabinoid hyperemesis syndrome. We investigated the population prevalence of FNVDs, their characteristics, and associated factors.

METHODS

In the year 2015, an Internet cross-sectional health survey was completed by 5931 adults in the general populations of 3 English-speaking countries; 2100 participants were in the United States, Canada, or the United Kingdom. Quota-based sampling was used to generate demographically balanced and population-representative samples. The survey collected data on demographics, health care visits, medications, somatic symptom severity, quality of life, and symptom-based diagnostic criteria for Rome IV FNVDs as well as for irritable bowel syndrome and functional dyspepsia. Subsequent comparisons were made between Rome IV FNVD subjects and individuals without FNVDs (controls).

RESULTS

Overall, 2.2% of the population (n = 131) fulfilled symptom-based diagnostic criteria for Rome IV FNVDs: the United States (3%) had a greater prevalence than Canada (1.9%) or the United Kingdom (1.8%) (P = .02). The prevalence of CNVS was similar among the countries, ranging from 0.8% to 1.2%. However, the prevalence of CVS was higher in the United States (2%) than in Canada (0.7%) or the United Kingdom (1%) (P = .03). The proportion of subjects with CVS taking cannabis did not differ significantly among countries (P = .31), although the 7 cases of cannabinoid hyperemesis syndrome were in the United States. A significantly higher proportion of subjects with CVS reported a compulsive need for hot water bathing to alleviate emetic symptoms than subjects with CNVS (44% vs 19%; P = .03); this behavior was independent of cannabis but augmented by its use. Subjects with FNVDs had significantly greater health impairment and health care utilization than controls. On multivariate analysis, independent factors associated with FNVDs were younger age, increasing somatic symptom severity, lower quality of life, presence of irritable bowel syndrome, and functional dyspepsia. However, on subgroup analysis, somatic symptom severity was associated with CVS but not CNVS, whereas poor quality of life was associated with CNVS but not CVS.

CONCLUSIONS

Based on a cross-sectional health survey of adults in the general populations of 3 English-speaking countries, approximately 2% of subjects meet symptom-based criteria for Rome IV FNVDs and have considerable health impairments. Hot water bathing to alleviate emetic symptoms is reported for all FNVDs, and is perpetuated by cannabis use.

Migraine, Cyclic Vomiting Syndrome, and Other Gastrointestinal Disorders

PURPOSE OF REVIEW

Cyclic vomiting syndrome (CVS) is a chronic functional gastrointestinal disorder characterized by episodic nausea and vomiting and is diagnosed using Rome IV criteria. CVS is being recognized more frequently in adults with a prevalence of 2%. It is associated with several functional disorders like autonomic dysfunction, anxiety, and depression, but the strongest association is with migraine. We will elucidate the close relationship between migraine and CVS and briefly discuss its association with other gastrointestinal disorders.

RECENT FINDINGS

We highlight similarities in pathophysiology, clinical presentation, and response to medications between CVS and migraine (tricyclic antidepressants, triptans, antiepileptics). We also discuss novel therapies like CGRP inhibitors which are effective in migraine and have potential for adaptation in patients with CVS. Using migraine as a template should enable investigators to elucidate the mechanisms underlying this disorder, develop novel therapies, and direct future research in CVS.

Cyclic vomiting syndrome: diagnostic approach and current management strategies

Cyclic vomiting syndrome (CVS) is a disorder characterized by episodes of nausea and vomiting lasting for 1-5 days followed by asymptomatic periods. The etiology of CVS is unknown, but it shares similar characteristics to migraine headaches. CVS is generally classified as having four phases: prodromal, acute/vomiting/hyperemesis, recovery, and remission/interepisodic. Current management strategies include trigger avoidance, abortive and prophylactic medication therapies, and supportive care. The goal of therapy for the remission phase is prophylaxis of further episodes. Antidepressant, antiepileptic, and antimigraine medications show an overall reduction or remission of CVS symptoms in more than 70% of patients. This article provides a summary of diagnostic strategies and reviews current management strategies for CVS.

Cyclic vomiting syndrome: epidemiology, diagnosis, and treatment

Cyclic-vomiting syndrome (CVS) is a chronic functional gastrointestinal disorder characterized by recurrent episodes of nausea and vomiting. Although once thought to be a pediatric disorder, there has been a considerable increase in recognition of CVS in adults. The exact pathogenesis is unknown and several theories have been proposed. Migraine and CVS share a similar pathophysiology as suggested by several studies. Since there are no specific biomarkers available for this disorder, physicians should rely on Rome criteria for the diagnosis. Due to the lack of randomized control trials, the treatment of CVS is primarily empirical.

Prophylactic Therapy of Cyclic Vomiting Syndrome in Children: Comparison of Amitriptyline and Cyproheptadine: A Randomized Clinical Trial

OBJECTIVES

Cyclic vomiting syndrome (CVS) is a common functional gastrointestinal disorder characterized by recurrent episodes of nausea and vomiting. There is no definite treatment for the condition, although some medications are recommended. We aimed to compare the efficacy of amitriptyline and cyproheptadine in prophylactic therapy of CVS.

METHODS

This is a single-blinded randomized clinical trial conducted during 2015-2016 in Isfahan, Iran. Sixty-four children who were 3-15 years old, with a diagnosis of CVS (based on Rome III criteria), were included in the study and were randomly divided into two groups of amitriptyline and cyproheptadine. They were followed for 6 months, looking for frequency and duration of attacks as the primary outcome.

RESULTS

The mean monthly frequency of attacks in the last 2 months of the study in the amitriptyline and cyproheptadine group were 0.38±0.55 and 0.59±0.71, respectively (P-value=0.197), after intervention. The mean duration of attacks between amitriptyline and cyproheptadine group were 1.41±2.86 and 1.81±2.22 h, respectively (P-value=0.212). In the amitriptyline group 65.6% of patients reported 100% remission, whereas in the cyproheptadine group 50% reported full remission (P-value=0.206).

CONCLUSIONS

There was no superiority of one of the medications over the other. We did not find any age-related effect on the efficacy of these medications as well.

Cyclic vomiting syndrome: a case series and review of the literature

OBJECTIVE

Cyclic vomiting syndrome (CVS) is under-recognised. Treatment is difficult as the pathophysiology is incompletely understood. We report our experience of treating patients with amitriptyline, and review the literature to summarise symptoms and associated features, epidemiology, potential pathophysiological mechanisms, differential diagnoses and treatment.

DESIGN

Consecutive adult patients with CVS were identified during a 5-year period from January 2010 until December 2015. Medical records were reviewed retrospectively, and age and sex of the patient, symptoms, associated features and response to treatment with amitriptyline were recorded.

SETTING

A luminal gastroenterology clinic at a teaching hospital.

RESULTS

Seventeen patients were identified (mean age 29.8 years, 13 (76.5%) female). Five had a history of cannabis use. Duration of symptoms prior to diagnosis ranged from 5 months to 15 years. Fourteen patients commenced amitriptyline, and in eight (57.1%) symptoms either ceased entirely or improved. Review of the literature suggested the prevalence of CVS was 0.5%. Symptoms are stereotypical, with acute episodes of nausea and vomiting, interspersed by periods when the patient is symptom-free. Proposed pathophysiologies include neuroendocrine dysfunction, mutations in mitochondrial DNA and re-intoxication effects from cannabis stored in fat tissues. Treatment during the acute phase is supportive, with rehydration, sedation and antiemetics. Prophylaxis to prevent future attacks with antihistamines, antimigraine drugs, antiepileptics and tricyclic antidepressants may be beneficial. Complete cessation of cannabis smoking should be advised.

CONCLUSIONS

Diagnosis of CVS is often delayed in adults. Once identified, patients respond well to amitriptyline.

Clinical Characteristics, Comorbidities and Hospital Outcomes in Hospitalizations with Cyclic Vomiting Syndrome: A Nationwide Analysis

BACKGROUND

Data on cyclic vomiting syndrome (CVS) are limited to studies from tertiary care centers. There is a paucity of information about CVS on a national scale.

AIM

To study the clinical characteristics, comorbidities, and hospital outcomes in patients hospitalized with CVS using a nationwide database.

METHODS

We identified all hospitalizations associated with a primary diagnosis of CVS in 2010 and 2011 using the Nationwide Inpatient Sample with an age category of 18-55 years. A 1:2 random sample of non-CVS hospitalizations with the same age category was obtained, and comparisons between groups were made. Multivariate logistic regression analysis was used to determine comorbidities independently associated with CVS.

RESULTS

Our study included 20,952 CVS and 44,262 non-CVS patients. CVS patients tended to be younger, male, and white compared to non-CVS patients. On multivariate analysis, CVS was significantly associated with comorbidities including dysautonomia, migraine, anxiety, marijuana use, irritable bowel syndrome, gastroparesis, gastroesophageal reflux disease, asthma, cigarette smoking, and hypertension. CVS patients underwent esophagogastroduodenoscopy, colonoscopy, and gastric emptying tests more frequently. They had more favorable hospital outcomes like more routine discharges (discharge to home/self-care), lower mortality, and shorter length of stay but tended to leave against medical advice more frequently. CVS patients incurred total hospital charges of about $400 million over the 2 years.

CONCLUSIONS

Our study showed that CVS is associated with several comorbidities and incurred substantial health care costs despite benign outcomes. Efforts to optimize therapy of CVS, manage comorbid conditions and reduce healthcare utilization are warranted.

Cyproheptadine: A Potentially Effective Treatment for Functional Gastrointestinal Disorders in Children

Functional gastrointestinal disorders (FGIDs) negatively affect children's quality of life and health care costs. It has been proposed that alteration of gut serotonin leads to gastrointestinal dysmotility, visceral hypersensitivity, altered gastrointestinal secretions, and brain-gut dysfunction. Cyproheptadine, a serotonin antagonist, has been shown to be a potentially effective and safe treatment option in children who meet the clinical criteria for FGIDs. Well-designed multicenter trials with long-term follow-up are needed to further investigate its efficacy. [Pediatr Ann. 2017;46(3):e120-e125.].

The Cyclic Vomiting Syndrome Threshold: A Framework for Understanding Pathogenesis and Predicting Successful Treatments

Cyclic vomiting syndrome (CVS) is an uncommon, idiopathic disorder defined by recurrent, sudden-onset attacks of repetitive retching and vomiting that are separated by symptom-free intervals. CVS was long regarded as a disorder primarily experienced by children but is now known to present de novo in adulthood. Adult CVS has garnered more research attention over the past 20 years, and these efforts have identified some acute and prophylactic treatments for this disorder. However, CVS still lacks a unifying disease model, and this has hindered the development of new therapies. Here adult CVS is reframed as a neurogenic disorder, driven by various endophenotypic factors that shape patterns of activity within the neural circuits required for disease expression. The concept of the "CVS threshold" is put forth in parallel with exploring the remarkable similarity of adult CVS with features of chronic migraine, epilepsy, and panic disorder. Because of such shared neural mechanisms and overlapping endophenotypes, many therapies that have been developed for these other disorders could also be useful in managing CVS. This review seeks to achieve three primary aims: (1) to develop a comprehensive, explanatory framework for adult CVS pathogenesis, (2) to use this framework for identifying potentially novel therapies for CVS, and (3) to describe future research directions that are needed to move the field forward.

Endocannabinoid-related lipids are increased during an episode of cyclic vomiting syndrome

BACKGROUND

The endocannabinoid system and the hypothalamic-pituitary-adrenal axis are important neuromodulators of nausea and vomiting. This led us to hypothesize that patients with cyclic vomiting syndrome (CVS) have lower serum endocannabinoids (eCBs) and higher salivary cortisol and alpha amylase.

METHODS

Serum eCBs and related lipids, N-oleoylethanolamine (OEA) and N-palmitoylethanolamide (PEA), and salivary cortisol, and alpha amylase (index of sympathetic nervous system activity) were measured in 22 CVS patients (age 40 ± 11, female = 17) in the well and sick phases and 12 matched controls (age 37 ± 12, female = 10).

KEY RESULTS

Contrary to our hypothesis, serum concentrations of the eCBs were not different among the study groups. However, serum concentrations of OEA and PEA were significantly higher during the sick than well phase in CVS patients (p = 0.001 and p = 0.04). There were positive correlations between serum PEA and nausea scores in the sick phase (Pearson's rho = 0.48, p = 0.036) and between serum OEA and poor sleep quality in patients (Pearson's rho = 0.7, p = 0.0005). Salivary cortisol and alpha amylase were not different between patients and controls, but subgroup analysis revealed that both were significantly higher in marijuana users compared to non-users during the sick phase (p = 0.04 and 0.03, respectively).

CONCLUSIONS & INFERENCES

These data demonstrate that eCB-related lipids, OEA and PEA, are mobilized in the sick phase of CVS and are positively correlated with several of the symptoms of a CVS episode. These data also suggest the hypothesis that chronic marijuana use results in enhanced stress responses during CVS.

Cyclic Vomiting Syndrome: A Functional Disorder

Cyclic vomiting syndrome (CVS) is a functional disorder characterized by stereotypical episodes of intense vomiting separated by weeks to months. Although it can occur at any age, the most common age at presentation is 3-7 years. There is no gender predominance. The precise pathophysiology of CVS is not known but a strong association with migraine headaches, in the patient as well as the mother indicates that it may represent a mitochondriopathy. Studies have also suggested the role of an underlying autonomic neuropathy involving the sympathetic nervous system in its pathogenesis. CVS has known triggers in many individuals and avoiding these triggers can help prevent the onset of the episodes. It typically presents in four phases: a prodrome, vomiting phase, recovery phase and an asymptomatic phase until the next episode. Complications such as dehydration and hematemesis from Mallory Wise tear of the esophageal mucosa may occur in more severe cases. Blood and urine tests and abdominal imaging may be indicated depending upon the severity of symptoms. Brain magnetic resonance imaging and upper gastrointestinal endoscopy may also be indicated in certain circumstances. Management of an episode after it has started ('abortive treatment') includes keeping the patient in a dark and quiet room, intravenous hydration, ondansetron, sumatriptan, clonidine, and benzodiazepines. Prophylactic treatment includes cyproheptadine, propranolol and amitriptyline. No mortality has been reported as a direct result of CVS and many children outgrow it over time. A subset may develop other functional disorders like irritable bowel syndrome and migraine headaches.

OnabotulinumtoxinA Injections for the Treatment of Cyclic Vomiting Syndrome

Cyclic vomiting syndrome (CVS) is a disorder characterized by episodes of nausea and vomiting lasting 1 to 5 days, followed by asymptomatic periods. The etiology and pathophysiology of CVS are unknown, but CVS shares similar characteristics to those of migraine headaches. Tricyclic antidepressants have the most evidence and are generally effective for prophylaxis of further episodes in patients with CVS. Second-line pharmacotherapies typically target specific comorbid symptoms or conditions and may include antiepileptic or antimigraine drugs, benzodiazepines, antispasmodics, proton pump inhibitors, antiemetics, and analgesics. OnabotulinumtoxinA (ONABoNT-A) injections have not been studied in the population with CVS but are regarded as a pharmacotherapeutic option for migraine headaches. We describe a 45-year-old woman with a 5-year history of CVS who had failed previous typical prophylactic migraine and CVS pharmacotherapies and was referred to the neurology clinic for management of both of these conditions. On review, the neurologist noted a correlation of the patient's headaches with her CVS symptoms. ONABoNT-A injections were started at 155 units intramuscularly every 12 weeks for her migraine headaches, which also dramatically improved her CVS. The main adverse effect reported by the patient was numbness and weakness in her left shoulder after the injections, which are symptoms consistent with ONABoNT-A injection use; however, these symptoms typically resolved a few days later. Regarded as a pharmacotherapeutic option for migraine headache prophylaxis, ONABoNT-A injections have demonstrated modest efficacy in preventing migraine headaches. Clinicians should be aware that ONABoNT-A injections may also have a role in the prophylaxis of CVS.

Rapid or normal gastric emptying as new supportive criteria for diagnosing cyclic vomiting syndrome in adults

Background

Cyclic vomiting syndrome (CVS) in adults is a disorder characterized by recurrent and stereotypic episodes of severe nausea, vomiting and abdominal pain separated by symptom-free intervals. Our goal was to investigate gastric emptying (GE) in CVS patients.

Material/Methods

This was a retrospective study of 30 adult patients who met Rome III diagnostic criteria for CVS. Rapid GE was defined using two different predefined criteria as either <50% isotope retention or <65% isotope retention at 1^st hour and/or <20% at 2^nd hour.

Results

Of the 30 patients (25 had 4-hr GE) diagnosed with CVS, 22 were females and 8 males with a mean age of 39 years. Overall, 20 (80%) of the 25 CVS patients met the predefined criteria of <50% retention for rapid GE in the first hour. Fifteen (60%) met the 2-hour criteria for rapid emptying of <20% retention. Five (16.6%) patients of the 25 had a normal GE with a mean retention at the first hour of 65% (52–78%). Nine (36%) also met another predefined criteria of <35% retention for rapid GE in the first hour. Sixteen (64%) met criteria for normal GE.

Conclusions

(1) In adult CVS patients, GE is either rapid or normal, clearly distinguishing this entity from gastroparesis. (2) Cyclic vomiting syndrome is an important new etiology to explain the finding of rapid GE on a radionuclide test. (3) We suggest that rapid gastric emptying should be added as supportive criteria for diagnosing CVS in adults.

Cyclic vomiting syndrome: treatment options

Cyclic vomiting syndrome is a disorder characterized by recurrent episodes of severe nausea and vomiting separated by symptom-free periods. Our aims were to review treatments of adult cyclic vomiting syndrome as well as to identify areas for further clinical research and the unanswered questions in this field. We conducted a PubMed search using such keywords as "cyclic vomiting syndrome," "nausea," "vomiting," "treatment," "trigger factors" and "tricyclic antidepressants" and combined this information with the knowledge and clinical research from the authors. Available data show that in adult cyclic vomiting syndrome, there is an impressive and sustained response to high-dose tricyclic antidepressants. In up to 13% who are regarded as poor responders to tricyclic antidepressants, a predictable profile can be identified related to coexisting psychological disorders, marijuana use, poorly controlled migraine headache or chronic narcotic use. Cyclic vomiting syndrome in adults is being an increasingly recognized entity. Tricyclic antidepressants are the main treatment for controlling symptoms. Eliminating and addressing trigger factors are an essential part of management.

Gastrointestinal manifestations of pediatric autonomic disorders

Functional gastrointestinal disorders (FGIDs) are currently classified under the Rome criteria based on symptoms and absence of organic disease. Preliminary studies have shown that FGIDs are probably not restricted to the GI tract, but may represent a systemic disorder with comorbidities affecting other parts of the body, including migraine, fatigue, aches and pains, etc. The autonomic nervous system (ANS) provides the extrinsic control of GI motility, secretions, and even immune response. The role of the ANS in the development of FGIDs and comorbidities is still unclear. Limited data demonstrate orthostatic intolerance such as reflex syncope and postural tachycardia syndrome in a large subset of subjects with FGIDs. Some studies have found improvement in the GI symptoms with treatment of the orthostatic intolerance it produces. Prospective studies are needed to determine the chronology of the development of the comorbidities, the triggers that induce these syndromes, and effective treatments. This chapter aims to review current understanding of the role of the ANS in FGIDs.

Cyclic Vomiting Syndrome (CVS): is there a difference based on onset of symptoms--pediatric versus adult?

BACKGROUND

Cyclic Vomiting Syndrome (CVS) is a well-recognized functional gastrointestinal disorder in children but its presentation is poorly understood in adults. Genetic differences in pediatric-onset (presentation before age 18) and adult-onset CVS have been reported recently but their clinical features and possible differences in response to therapy have not been well studied.

METHODS

This was a retrospective review of 101 CVS patients seen at the Medical College of Wisconsin between 2006 and 2008. Rome III criteria were utilized to make the diagnosis of CVS.

RESULTS

Our study population comprised of 29(29%) pediatric-onset and 72 (71%) adult-onset CVS patients. Pediatric-onset CVS patients were more likely to be female (86% vs. 57%, p = 0.005) and had a higher prevalence of CVS plus (CVS + neurocognitive disorders) as compared to adult-onset CVS patients (14% vs. 3%, p = 0.05). There was a longer delay in diagnosis (10 ± 7 years) in the pediatric-onset group when compared to (5 ± 7 years) adult-onset CVS group (p = 0.001). Chronic opiate use was less frequent in the pediatric-onset group compared to adult-onset patients (0% vs. 23%, p = 0.004). Aside from these differences, the two groups were similar with regards to their clinical features and the time of onset of symptoms did not predict response to standard treatment. The majority of patients (86%) responded to treatment with tricyclic antidepressants, anticonvulsants (topiramate), coenzyme Q-10, and L-carnitine. Non-response to therapy was associated with coalescence of symptoms, chronic opiate use and more severe disease as characterized by longer episodes, greater number of emergency department visits in the year prior to presentation, presence of disability and non-compliance on univariate analysis. On multivariate analysis, only compliance to therapy was associated with a response. (88% vs. 38%, Odds Ratio, OR 9.6; 95% Confidence Interval [CI], 1.18-77.05).

CONCLUSION

Despite reported genetic differences, the clinical features and response to standard therapy in pediatric- and adult-onset CVS were mostly similar. Most patients (86%) responded to therapy and compliance was the only factor associated with a response.

Cyclic vomiting syndrome and functional vomiting in adults: association with cannabinoid use in males

BACKGROUND

Cyclic vomiting syndrome (CVS) is characterized by stereotypical episodes of vomiting separated by symptom-free intervals. However, the difficulty encountered in the management of patients with CVS may be a reflection of a deficiency in our understanding of the disorder. We aimed to evaluate whether clinical or gastric emptying (GE) data discriminate patients labeled as having CVS from functional vomiting (FV) or irritable bowel syndrome (IBS).

METHODS

The medical records of patients diagnosed with any vomiting (including CVS, FV) over a 13-year period (1993-2006) at our institution were carefully reviewed. Disease controls were age and gender matched subjects with IBS. Gastric emptying was performed by scintigraphy (99mTc-egg meal). The associations of clinical factors and GE data with patient status (CVS vs FV or IBS) were analyzed.

KEY RESULTS

A total of 82 patients with CVS and 62 FV patients were identified. Younger age [per 10 years, OR = 0.7 (0.5, 0.9)], male gender [OR = 0.4 (0.2, 0.9)], and cannabinoid use [OR = 2.9 (1.2, 7.2)] were significantly associated with CVS compared with FV. However, there were no significant associations between patient status (CVS vs FV) and age, BMI, smoking, alcohol use, gastrointestinal symptoms, or GE. The proportion of cannabinoid users was significantly higher in patients with CVS compared with patients with IBS, whereas proportions for headaches and psychiatric disease were higher in subjects with IBS.

CONCLUSIONS & INFERENCES

Cyclic vomiting syndrome (vs FV) was not associated with clinical factors, but was associated with younger age, male gender and cannabinoid use. A larger proportion of CVS (vs IBS) patients had used cannabinoids.

Review article: cyclic vomiting syndrome in adults--rediscovering and redefining an old entity

BACKGROUND

Cyclic vomiting syndrome is a disorder characterised by recurrent episodes of severe nausea and vomiting separated by symptom-free periods.

AIMS

To review the history, epidemiology, clinical aspects, pathophysiology, diagnosis and treatments of adult cyclic vomiting syndrome as well as to identify areas for further clinical research and the unanswered questions in this field.

METHODS

We conducted a PubMed search using such keywords as cyclic vomiting syndrome; nausea; vomiting; pathophysiology; diagnosis; treatment; trigger factors; gastric emptying test; autonomic nerve function test; gastrointestinal hormones; outcome and natural history and combined this information with the knowledge and extensive clinical research and publications from the authors.

RESULTS

Available data show that in adult cyclic vomiting syndrome, severe epigastric and sometimes diffuse abdominal pain accompanies most cycles of nausea and vomiting interspersed with periods of symptomatic remission. Psychological disorders, specifically anxiety and depression are common, and gastric emptying is actually rapid in approximately 60% of patients and normal in the remainder. There is an impressive and sustained response to high-dose tricyclic antidepressants. In up to 15% who are regarded as poor responders to tricyclic antidepressants, a predictable profile can be identified related to co-existing psychological disorders, marijuana use, poorly controlled migraine headache or chronic narcotic use.

CONCLUSIONS

Cyclic vomiting syndrome in adults is an entity that is being increasingly recognised, but the need to educate Internists, Gastroenterologists and Emergency Department staff remains an ongoing challenge.