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.

Characterizing Asian American medical students' experiences with microaggression and the impact on their well-being.

PURPOSE: This mixed-methods study quantified and characterized incidents of microaggressions experienced by Asian American medical students. The authors report on their impact and suggest improvements to create a more equitable and supportive learning environment. METHOD: Quantitative and qualitative data were collected from 305 participants who self-identified as Asian American or Pacific Islander. An online, anonymous survey was sent to US medical students through the Asian Pacific American Medical Student Association (APAMSA). Questions explored incidence, characteristics of, and response to microaggressions. We conducted four focus groups to further characterize students' experiences. Data were organized and coded, and thematic analysis was used to identify core themes. RESULTS: Racial microaggressions were prevalent among Asian American medical students. Nearly 70% (n = 213) of survey respondents reported experiencing at least one incident during their medical training to date. The most common perpetrators were patients (n = 151, 70.9%) and fellow medical students (n = 126, 59.2%), followed by professors (n = 90, 42.3%). The most prevalent themes included being perceived as a perpetual foreigner, the assumption of timidness, and ascription of the model minority myth. Students rarely reported the incident and usually did not respond immediately due to fear of retaliation, uncertainties about the experience or how to respond appropriately, and perception that they would bear the burden of advocacy alone. Experiences with microaggressions led to feelings of frustration and burnout and had a negative impact on mental health. Recommendations were made to improve the anonymous reporting systems in medical schools, and to increase diversity and inclusion in medical education and leadership. CONCLUSIONS: Asian American medical students face high exposure to racial microaggressions during their medical education that adversely impact their mental health. Changes are needed in medical training to create a more equitable and inclusive learning environment.

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.

Percutaneous Electrical Nerve Field Stimulation for Drug-Refractory Pediatric Cyclic Vomiting Syndrome.

BACKGROUND: Cyclic vomiting syndrome (CVS) is a disabling condition frequently refractory to pharmacologic therapy. The aim of this study was to evaluate the effects of noninvasive, auricular percutaneous electrical nerve field stimulation (PENFS) as prophylactic therapy for pediatric CVS. METHODS: Children 8-18 years with drug-refractory CVS were prospectively enrolled from a tertiary care CVS clinic. Subjects received 6 consecutive weeks of PENFS. CVS severity was quantified by episode frequency and duration score (range 0-25) at baseline and at extended follow-up (4-6 months after end of therapy). Response was classified as ≥50% improvement in either frequency or duration of attacks at extended follow-up. Subjects also completed validated surveys of nausea, disability, and global response. RESULTS: Thirty subjects completed the study. Median (interquartile range, IQR) age was 10.5 (8.5-15.5) years; 60% were female. At follow-up, 80% met criteria for treatment response with a median (IQR) response duration of 113 (61-182) days. The frequency-duration score improved from baseline median (IQR) 12.0 (9.0-16.0) to 3.0 (1.0-6.0) at follow-up, P < 0.0001. Median (IQR) nausea and disability scores decreased from baseline to week 6: 2.1 (1.3-2.7) to 0.9 (0-1.6), P = 0.003 and 47.5 (41.0-53.0) to 38.0 (16.0-51.0), P = 0.001, respectively. At end of therapy, 66% and 55% patients reported global response of at least "moderately better" and "a good deal better," respectively. There were no serious side effects. CONCLUSIONS: This study suggests long-term benefits of PENFS for children with CVS. PENFS improves several disabling aspects of CVS, including episode frequency, duration, and functional disability.

Equity and Inclusion in Pediatric Gastroenterology Telehealth: A Study of Demographic, Socioeconomic, and Digital Disparities.

OBJECTIVES: The purpose of our study is to compare in-person and telehealth pediatric care ambulatory visits for gastroenterology (GI) at the Nemours Children's Health System in the Delaware Valley (NCH-DV) based on geospatial, demographic, socioeconomic, and digital disparities. METHODS: Characteristics of 26,565 patient encounters from January 2019 to December 2020 were analyzed. U.S. Census Bureau geographic identifiers were assigned to each participant and aligned with the American Community Survey (2015-2019) socioeconomic and digital outcomes. Reported odds ratios (OR) are telehealth encounter/in-person encounter. RESULTS: GI telehealth usage increased 145-fold in 2020 compared to 2019 for NCH-DV. Comparing telehealth to in-person usage in 2020 revealed that GI patients who required a language translator were 2.2-fold less likely to choose telehealth [individual level adjusted OR (I-OR a ) [95% confidence interval, CI], 0.45 [0.30-0.66], P < 0.001]. Individuals of Hispanic ethnicity or non-Hispanic Black or African American race are 1.3-1.4-fold less likely to utilize telehealth than non-Hispanic Whites (I-OR a [95% CI], 0.73 [0.59-0.89], P = 0.002 and 0.76 [0.60-0.95], P = 0.02, respectively). Households in census block groups (BG) that are more likely to utilize telehealth: have broadband access (BG-OR = 2.51 [1.22-5.31], P = 0.014); are above the poverty level (BG-OR = 4.44 [2.00-10.24], P < 0.001); own their own home (BG-OR = 1.79 [1.25-2.60], P = 0.002); and have a bachelor's degree or higher (BG-OR = 6.55 [3.25-13.80], P < 0.001). CONCLUSIONS: Our study is the largest reported pediatric GI telehealth experience in North America that describes racial, ethnic, socioeconomic, and digital inequities. Advocacy and research for pediatric GI focused on telehealth equity and inclusion is urgently needed.

North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position Statement for Telehealth.

Telehealth (TH) broadly encompasses remote activities of clinical care (telemedicine), provider and patient education, and general health services. The use of synchronous video for TH first occurred in 1964 and then catapulted to the forefront in 2020 during the coronavirus disease 2019 public health emergency. Due to the sudden need for increased TH utilization by nearly all health care providers at that time, TH became essential to clinical practice. However, its sustainable future is unclear in part given that best practices for TH in pediatric gastroenterology (GI), hepatology, and nutrition remain undefined and non-standardized. Key areas for review include historical perspective, general and subspeciality usage, health care disparities, quality of care and the provider-patient interaction, logistics and operations, licensure and liability, reimbursement and insurance coverage, research and quality improvement (QI) priorities, and future use of TH in pediatric GI with a call for advocacy. This position paper from the Telehealth Special Interest Group of North American Society of Gastroenterology, Hepatology and Nutrition provides recommendations for pediatric GI-focused TH best practices, reviews areas for research and QI growth, and presents advocacy opportunities.

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.

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.

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.

Telehealth for Pediatric Gastroenterology Care Now: The Transition to Telehealth and the Impact of Webinar-Based Didactics.

With the coronavirus disease 2019 public health emergency (PHE), telehealth (TH) became essential for continued delivery of care. Members of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) formed the Telehealth for Pediatric Gastrointestinal Care Now (TPGCN) working group and rapidly organized a telemedicine webinar to provide education and guidance. We aim to describe the webinar development and prospectively assess the effectiveness of this webinar-based educational intervention. Methods: NASPGHAN members who registered for the TPGCN webinar received pre- and post-webinar surveys. Outcome measures included a modified Telehealth Acceptance Model (TAM) survey and a Student Evaluation of Educational Quality (SEEQ) standardized instrument. Results: Seven hundred seventy-six NASPGHAN members participated in the webinar, 147 (33%) completed the pre-webinar survey; of these, 25 of 147 (17%) completed a post-webinar survey. Before the PHE, 50.3% of the pre-webinar survey participants had no TH knowledge. Webinar participants trended to have increased acceptance of TH for follow-up visits (pre-webinar, 68% versus post-webinar, 81%; P = 0.15) and chronic disease care (pre-webinar, 57% vs post-webinar, 81%; P = 0.01). The overall acceptance of TH as shown by TAM pre-webinar was 1.74 ± 0.8, which improved to 1.62 ± 0.8 post-webinar (lower scores indicate greater acceptance; P < 0.001). SEEQ results indicate that webinar material was understandable (post-webinar, 95%). Participants found breakout sessions informative and enjoyable (post-webinar, 91%). Conclusion: The TPGCN TH webinar was an effective educational intervention that fostered increased TH usage for follow-up and chronic care visits, improved TAM scores, and was well received by participants as seen by high SEEQ scores. Sustained and expanded pediatric gastrointestinal TH usage beyond the coronavirus disease 2019 PHE is expected.

Development and Assessment of a Low Literacy, Pictographic Cyclic Vomiting Syndrome Action Plan.

OBJECTIVE: To develop and assess an evidence-based, individualized Cyclic Vomiting Syndrome Action Plan (CVSAP) to optimize both preventative and acute care. STUDY DESIGN: This implementation science project synthesized a combination of clinical practice guidelines, published literature, and clinical experience by a team of CVS clinicians to develop the CVSAP. The tool was developed to include validated pictograms and an automatic, embedded, weight-based dosing calculator to output acute management recommendations. The final version of the CVSAP was tested by patients/caregivers, readability calculators, medical librarians, and clinicians using validated metrics. RESULTS: All pictograms met the criteria for inclusion in the CVSAP. A composite readability score of 5.32 was consistent with a fifth-grade level. Patients/caregivers (n = 70) judged the CVSAP to be of high quality with consumer information rating form rating of 84.2%. Six medical librarians rated the CVSAP to have 93% understandability and 100% actionability, and 33 clinicians completing the SAM generated a suitability rating of 87.5%. CONCLUSIONS: The CVSAP visually highlights individualized care plan components to facilitate optimized preventative and acute CVS care. Further investigation will determine if CVSAP increases caregiver confidence and compliance in home management and improves quality of life and clinical outcomes for patients with CVS.

Improvise, Adapt, Overcome: How COVID-19 Transformed Inpatient Pediatric Gastroenterology.

The coronavirus disease-2019 (COVID-19) pandemic has disrupted inpatient pediatric services across the United States, creating opportunities for innovation. A recent Webinar organized by the Telehealth for Pediatric GI Care Now working group and sponsored by the North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition provided insights into how inpatient pediatric gastroenterology services were affected and how physicians adapted during the crisis. These findings suggest the use of telehealth technologies may augment family communication and facilitate multidisciplinary care in the future. We anticipate that these innovative applications of telehealth will comprise a part of a toolkit for gastroenterologists to be used during this public health emergency and beyond.

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.

Proceedings of the 2018 Advances In Motility and In NeuroGastroenterology: AIMING for the Future Single Topic Symposium.

OBJECTIVES: Motility and functional disorders are common in children and often debilitating, yet these disorders remain challenging to treat effectively. At the 2018 Annual North American Society for Pediatric Gastroenterology, Hepatology and Nutrition meeting, the Neurogastroenterology and Motility Committee held a full day symposium entitled, 2018 Advances In Motility and In NeuroGastroenterology - AIMING for the future. The symposium aimed to explore clinical paradigms in pediatric gastrointestinal motility disorders and provided a foundation for advancing new scientific and therapeutic research strategies. METHODS: The symposium brought together leading experts throughout North America to review the state of the art in the diagnosis and management of motility and functional disorders in children. Presentations were divided into esophageal, antral duodenal, and colorectal modules. Each module included oral presentations by experts in the respective fields, leading to thought-provoking discussions. There were 2 breakout sessions with small group discussions on select topics, focusing on defining scientific insights into the diagnosis and management of pediatric functional gastrointestinal and motility disorders in a systematic, segment-based approach. CONCLUSIONS: The field of neurogastroenterology has made remarkable progress in the last decade. The current report summarizes the major learning points from the symposium highlighting the diagnosis and promising therapies on the horizon for pediatric neurogastrointestinal and motility disorders.

Efficacy of Auricular Neurostimulation in Adolescents With Irritable Bowel Syndrome in a Randomized, Double-Blind Trial.

BACKGROUND & AIMS: Auricular neurostimulation therapy, in which a noninvasive device delivers percutaneous electrical nerve field stimulation (PENFS) to the external ear, is effective in pediatric patients with functional abdominal pain disorders. Preclinical studies showed that PENFS modulates central pain pathways and attenuates visceral hyperalgesia. We evaluated the efficacy of PENFS in adolescents with irritable bowel syndrome (IBS). METHODS: We analyzed data from pediatric patients with IBS who participated in a double-blind trial at a tertiary care gastroenterology clinic from June 2015 through November 2016. Patients were randomly assigned to groups that received PENFS (n = 27; median age, 15.3 y; 24 female) or a sham stimulation (n = 23; median age, 15.6 y; 21 female), 5 days/week for 4 weeks. The primary endpoint was number of patients with a reduction of 30% or more in worst abdominal pain severity after 3 weeks. Secondary endpoints were reduction in composite abdominal pain severity score, reduction in usual abdominal pain severity, and improvement in global symptom based on a symptom response scale (-7 to +7; 0 = no change) after 3 weeks. RESULTS: Reductions of 30% or more in worst abdominal pain were observed in 59% of patients who received PENFS vs 26% of patients who received the sham stimulation (P = .024). The patients who received PENFS had a composite pain median score of 7.5 (interquartile range [IQR], 3.6-14.4) vs 14.4 for the sham group (IQR, 4.5-39.2) (P = .026) and a usual pain median score of 3.0 (IQR, 3.0-5.0) vs 5.0 in the sham group (IQR, 3.0-7.0) (P = .029). A symptom response scale score of 2 or more was observed in 82% of patients who received PENFS vs 26% of patients in the sham group (P ≤ .001). No significant side effects were reported. CONCLUSIONS: Auricular neurostimulation reduces abdominal pain scores and improves overall wellbeing in adolescents with IBS. PENFS is a noninvasive treatment option for pediatric patients with functional bowel disorders. ClinicalTrials.gov no: NCT02367729.

Cyclic vomiting syndrome: Pathophysiology, comorbidities, and future research directions.

Cyclic vomiting syndrome (CVS) is characterized by severe episodic emesis in adults and children. Cannabinoid hyperemesis syndrome is an increasingly recognized CVS-like illness that has been associated with chronic cannabis use. There are significant gaps in our understanding of the pathophysiology, clinical features, comorbidities, and effective management options of CVS. Recommendations for treating CVS are based on limited clinical data, as no placebo-controlled, randomized trials have yet been conducted. Diseases associated with CVS, including migraine, mitochondrial disorders, autonomic dysfunction, and psychiatric comorbidities, provide clues about pathophysiologic mechanisms and suggest potential therapies. We review our current understanding of CVS and propose future research directions with the aim of developing effective therapy. Establishing a multicenter, standardized registry of CVS patients could drive research on multiple fronts including developing CVS-specific outcome measures to broaden our understanding of clinical profiles, to serve as treatment end points in clinical trials, and to provide a platform for patient recruitment for randomized clinical trials. Such a robust database would also facilitate conduct of research that aims to determine the underlying pathophysiological mechanisms and genetic basis for CVS, as well as identifying potential biomarkers for the disorder. Soliciting government and industry support is crucial to establishing the necessary infrastructure and achieving these goals. Patient advocacy groups such as the Cyclic Vomiting Syndrome Association (CVSA), which partner with clinicians and researchers to disseminate new information, to promote ongoing interactions between patients, their families, clinicians, investigators, to support ongoing CVS research and education, must be an integral part of this endeavor.

Management of cyclic vomiting syndrome in adults: Evidence review.

BACKGROUND: This evidence review was conducted to inform the accompanying clinical practice guideline on the management of cyclic vomiting syndrome (CVS) in adults. METHODS: We followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework and focused on interventions aimed at prophylactic management and abortive treatment of adults with CVS. Specifically, this evidence review addresses the following clinical questions: (a) Should the following pharmacologic agents be used for prophylaxis of CVS: amitriptyline, topiramate, aprepitant, zonisamide/levetiracetam, or mitochondrial supplements? (b) Should the following pharmacologic agents be used for abortive treatment: triptans or aprepitant? RESULTS: We found very low-quality evidence to support the use of the following agents for prophylactic and abortive treatment of CVS: amitriptyline, topiramate, aprepitant, zonisamide/levetiracetam, and mitochondrial supplements. We have moderate certainty of evidence for the use of triptans as abortive therapy. We found limited evidence to support the use of ondansetron and the treatment of co-morbid conditions and complementary therapies. CONCLUSIONS: This evidence review helps inform the accompanying guideline for the management of adults with CVS which is aimed at helping clinicians, patients, and policymakers, and should improve patient outcomes.

Role of chronic cannabis use: Cyclic vomiting syndrome vs cannabinoid hyperemesis syndrome.

Cannabis is commonly used in cyclic vomiting syndrome (CVS) due to its antiemetic and anxiolytic properties. Paradoxically, chronic cannabis use in the context of cyclic vomiting has led to the recognition of a putative new disorder called cannabinoid hyperemesis syndrome (CHS). Since its first description in 2004, numerous case series and case reports have emerged describing this phenomenon. Although not pathognomonic, a patient behavior called "compulsive hot water bathing" has been associated with CHS. There is considerable controversy about how CHS is defined. Most of the data remain heterogenous with limited follow-up, making it difficult to ascertain whether chronic cannabis use is causal, merely a clinical association with CVS, or unmasks or triggers symptoms in patients inherently predisposed to develop CVS. This article will discuss the role of cannabis in the regulation of nausea and vomiting, specifically focusing on both CVS and CHS, in order to address controversies in this context. To this objective, we have collated and analyzed published case series and case reports on CHS in order to determine the number of reported cases that meet current Rome IV criteria for CHS. We have also identified limitations in the existing diagnostic framework and propose revised criteria to diagnose CHS. Future research in this area should improve our understanding of the role of cannabis use in cyclic vomiting and help us better understand and manage this disorder.