Pediatric Cyclic Vomiting Syndrome Research Articles

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

Cyclic vomiting syndrome (CVS) is a disabling condition frequently refractory to pharmacologic therapy. The aim of this study was to evaluate the effects of non-invasive, auricular percutaneous electrical nerve field stimulation (PENFS) as prophylactic therapy for pediatric CVS. 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. 30 subjects completed the study. Median (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. 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.

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

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. 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. 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. 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.

Association of Anxiety and Gastrointestinal Comorbidities in Repeat Hospital Admissions in Pediatric Cyclic Vomiting Syndrome.

Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder with recurrent episodes of intense nausea and vomiting and thus may require frequent hospitalizations. There is paucity of data exploring the association of psychiatric and gastrointestinal comorbidities in repeat hospitalizations among pediatric patients with CVS. We analyzed the Pediatric Health Information System database and included all patients up to 18 years of age with a diagnosis of CVS between 2016 and 2020. We excluded patients with chronic conditions, which mimic CVS. The primary outcome variable was 90-day admission rate, which was defined as a visit to emergency department or admission to observation/inpatient unit with a primary diagnosis of CVS within 90 days after an index CVS hospitalization. We evaluated a total of 2,604 hospitalizations represented by 1,370 unique individuals. The overall 90-day admission rate was 28.5%, which steadily decreased from 35.7% in 2016 to 23% in 2019 ( P < 0.001). Patients in the repeat hospitalization cohort were slightly older and more often men. Patients with repeat admissions had an increased proportion of anxiety and other gastrointestinal disorders. Multivariable logistic regression showed that anxiety, gastroesophageal reflux disease, functional dyspepsia, and abdominal migraine were associated with increased odds of repeat admissions. Ninety-day admission rates in pediatric CVS are decreasing overall, although still contributing to significant healthcare expenditure. Anxiety and gastrointestinal comorbidities were associated with increased risk of repeat admissions. Further prospective studies are needed to better understand the complex interactions of these comorbidities and their management affecting the natural course of CVS.

Natural History of Pediatric Cyclic Vomiting Syndrome: Progression to Dysautonomia.

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. 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. 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). 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.

Comparison of the Effect of Adding L-Carnitine to Propranolol in the Prevention of Cyclic Vomiting Syndrome Attacks in Children

Background: Cyclic Vomiting Syndrome (CVS) is an idiopathic, complex, multifactorial disorder that is often characterized by recurrent episodes of vomiting and is usually separated by asymptomatic episodes. Prophylaxis should be considered in children with frequent or severe periods. Prevention and treatment of CVS in children is very difficult and no specific and effective treatment has been proven in clinical trials. Propranolol is approved for the prophylaxis of CVS in children of all ages, but its effectiveness has been variable. In this study, we investigated the efficacy and safety of adding L-Carnitine to propranolol therapy in the prevention of pediatric CVS. Methods: 76 children who were diagnosed with CVS were included in this study. They were divided into two equal groups. The first group received high dose of Propranolol and the case group received L-Carnitine with low dose of propranolol for 6 months. Results: CVS attacks’ frequency in both groups of treatment with propranolol alone and in combination with L-Carnitine and propranolol, before and after the treatment was significantly reduced. But there is no significant difference between the two groups 70.6%) vs. 90.9%) (p-value=0.062). There was no significant reduction in the duration days between vomiting attack index in both groups (31.6 % vs.43.2%) (p-value= 0.345). Conclusion: Our research revealed that combination of low dose propranolol with L-Carnitine has comparable efficacy with high dose Propranolol in prophylaxis of CVS.

Clinical features and long-term outcomes in pediatric cyclic vomiting syndrome: A 9-year experience at three tertiary academic centers.

Pediatric cyclic vomiting syndrome (CVS) is a little-known clinical condition, frequently diagnosed with delay. This study aims to describe the clinical presentation and management and to define possible predictive factors of the disease outcome. In this retrospective study, all children who were diagnosed with CVS during the period 2010-2019 in three tertiary academic centers were included. The association between clinical variables and outcomes was investigated. Fifty-seven children were included (male/female ratio 1.3:1; mean age at diagnosis 8.2years). At the time of diagnosis, 63% of children had at least one episode every month. One or more prodromes were reported by 75% of patients. Family history of migraine was reported for 47% of children. Nearly, all of the children were started on prophylactic treatment. The median follow-up period was 29months±15. Overall, 56% of children had resolution of vomiting. Twenty-six percent of children developed migraine. There were no differences in gender, age at onset, duration of follow-up, severity, medication, family history, or trigger factors between children who underwent resolution of vomiting and those who did not, or between children who suffered from migraine or not at follow-up. Four types of disease outcome were recognized, that is, resolution of vomiting with or without associated symptoms; persistence of vomiting with or without associated symptoms. Cyclic vomiting syndrome clinical presentation has inter-individual variability. Most children recover at follow-up, but often develop further somatic symptoms. In this study, no clinical variable clearly predicted the evolution of the syndrome toward one or the other outcome.

Predictors of Hospital Admission for Pediatric Cyclic Vomiting Syndrome

To identify predictors of hospitalization in pediatric patients presenting to an emergency department (ED) for a cyclic vomiting syndrome (CVS) attack. 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. In total, 219 patients with CVS (usingInternational Statistical Classification of Diseases and Related Health Problems, 10th Revision) were identified, of which 65% met the inclusion criteria (median age 11years). 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 (>24hours) to the ED (P<.001), and longer wait time prior treatment with antiemetics (P=.029). 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.

Acute Management of Pediatric Cyclic Vomiting Syndrome: A Systematic Review

To synthesize quantitative and qualitative data on pharmacologic interventions of pediatric cyclic vomiting syndrome and their effectiveness in disease management in the acute care setting. Using keywords, 799 studies published up from December 1954 to February 2018 were extracted from MEDLINE via Pubmed, Embase via OVID, CINAHL via EBSCO, and Cochrane Controlled Trials Registry. Studies were evaluated for inclusion and exclusion by 2 independent reviewers using predetermined inclusion and exclusion criteria. The search yielded 84 studies for full review, of which 54 were included in the systematic review. Studies were subsequently separated into 1 group of 6 case series studies containing quantitative data on sumatriptan, ondansetron, phenothiazines, prokinetic agents, carbohydrate, isometheptene, and aprepitant; 1 one group consisting only of qualitative studies containing expert recommendations. Ondansetron has the most quantitative and qualitative evidence to support its inclusion in pediatric emergency department protocols as a rescue therapy. Sumatriptan and aprepitant are potential candidates for inclusion as abortive therapies. Qualitative data from retrospective studies and case reports are not applicable to a larger patient population. This report informs a need for controlled, prospective cohort studies and randomized, controlled trials to optimize current management protocols and to develop new medical interventions.

Family Health-related Quality of Life in Pediatric Cyclic Vomiting Syndrome.

The aim of the study was to evaluate the relationship of disease characteristics and child anxiety symptoms to family health-related quality of life (FHRQoL) in youth with cyclic vomiting syndrome (CVS). Forty-two parents of youth ages 8 to 18 years diagnosed with CVS completed the Family Impact Module of the PedsQL, a measure of the impact of the child's illness on the family. We evaluated the relationship of disease characteristics and child and parent proxy reports of anxiety symptoms on the Screen for Childhood Anxiety and Related Emotional Disorders to FHRQoL. Parent report of child anxiety symptoms and missed school days (mean = 11.93, standard deviation = 14.62) were the strongest predictors of FHRQoL (r = 0.33, df = 1.39, F = 8.51, P = 0.006). Other disease characteristics, including frequency, duration, chronicity of CVS episodes, and delay in initial CVS diagnosis were not significantly associated with the FHRQoL total score. Child anxiety symptoms by either parent and/or child report were associated with subscales of the FHRQoL, including family physical functioning, family communication, and family daily activities. HRQoL for the families assessed in this study was associated with anxiety symptoms to a greater extent than disease characteristics, indexing the importance of a biopsychosocial approach to CVS management. Screening for anxiety symptoms and support for school absences due to illness are indicated to help lessen the impact of CVS on the family as a whole.

A New Approach to the Prophylaxis of Cyclic Vomiting: Topiramate.

Background/AimsThe aim of this study was to compare the efficacy and tolerability of topiramate and propranolol in preventing pediatric cyclic vomiting syndrome.MethodsA retrospective medical-record review of patients who underwent prophylaxis after receiving a diagnosis of cyclic vomiting syndrome was performed. Patients who completed at least 12 months of treatment were included in the analysis. Responder rate, and adverse-event rates were also calculated from all patients. Response to treatment was assessed as the total number of vomiting attacks per year. Patients in whom the frequency of vomiting attack reduced greater or equal to 50% were defined as responders, and the remaining patients were classified as nonresponders.ResultsA total of 38 patients who were treated prophylactically with either topiramate (16 patients) or propranolol (22 patients) were identified. Fifty-nine percent of the patients in the propranolol group and 81% of the patients in the topiramate group reported freedom from attacks. A decrease of more than 50% in attacks per year occurred in 23% of patients in the propranolol group and 13% of patients in the topiramate group. The responder rates were 81% for propranolol group and 94% for topiramate group (P = 0.001). Despite minor adverse effects (drowsiness, nervousness, and dizziness) observed in a few patients, the adverse event rates were not significantly different between the 2 groups (P = 0.240).ConclusionsThe efficacy of topiramate was superior to propranolol for the prophylaxis of pediatric cyclic vomiting syndrome.

Mitochondrial Dysfunction in Migraine

Migraine is the most frequent type of headache in children. In the 1980s, scientists first hypothesized a connection between migraine and mitochondrial (mt) disorders. More recent studies have suggested that at least some subtypes of migraine may be related to a mt defect. Different types of evidence support a relationship between mitochondria (mt) and migraine: (1) Biochemical evidence: Abnormal mt function translates into high intracellular penetration of Ca(2+), excessive production of free radicals, and deficient oxidative phosphorylation, which ultimately causes energy failure in neurons and astrocytes, thus triggering migraine mechanisms, including spreading depression. The mt markers of these events are low activity of superoxide dismutase, activation of cytochrome-c oxidase and nitric oxide, high levels of lactate and pyruvate, and low ratios of phosphocreatine-inorganic phosphate and N-acetylaspartate-choline. (2) Morphologic evidence: mt abnormalities have been shown in migraine sufferers, the most characteristic ones being direct observation in muscle biopsy of ragged red and cytochrome-c oxidase-negative fibers, accumulation of subsarcolemmal mt, and demonstration of giant mt with paracrystalline inclusions. (3) Genetic evidence: Recent studies have identified specific mutations responsible for migraine susceptibility. However, the investigation of the mtDNA mutations found in classic mt disorders (mt encephalomyopathy with lactic acidosis and stroke-like episodes, myoclonus epilepsy with ragged red fibers, Kearns-Sayre syndrome, and Leber hereditary optic neuropathy) has not demonstrated any association. Recently, 2 common mtDNA polymorphisms (16519C→T and 3010G→A) have been associated with pediatric cyclic vomiting syndrome and migraine. Also, POLG mutations (eg, p.T851 A, p.N468D, p.Y831C, p.G517V, and p.P163S) can cause disease through impaired replication of mtDNA, including migraine. Further studies to investigate the relationship between mtDNA and migraine will require very large sample sizes to obtain statistically significant results. (4) Therapeutic evidence: Several agents that have a positive effect on mt metabolism have shown to be effective in the treatment of migraines. The agents include riboflavin (B2), coenzyme Q10, magnesium, niacin, carnitine, topiramate, and lipoic acid. Further study is warranted to learn how mt interact with other factors to cause migraines. This will facilitate the development of new and more specific treatments that will reduce the frequency or severity or both of this disease.

Clinical Characteristics of Patients with Cyclic Vomiting Syndrome in Southern Iran

Background: Cyclic vomiting syndrome (CVS) is characterized by recurrent episodes of intense nausea and vomiting interpreted with symptom free period. As data regarding the pattern of disease in our region is scarce, we performed this study to investigate the pattern of pediatric CVS in southern Iran. Method: This was a retrospective analysis of 43 patients admitted to Nemazee hospital from 2000 to 2010 with diagnosis of cyclic vomiting according to the American Society for Pediatric Gastroenterology,Consensus criteria. The patients' medical charts were reviewed and the demographic, epidemiologic, laboratory, data were recruited using a standard questionnaire and further analyzed. Result: Overall we included 43 patients with CVS among whom there were 26 (60.5%) girls and 17 (39.5%) boys. The mean age at first attack was found to be 6.2±3.7 years (range 2 month to 15 years). Intractable vomiting was found in 16 (37%) patients and it was more common than any other type of vomiting. 10 patients (23.3%) had family history of migraine among which there were 8 female. The most clinical complaint was found to be abdominal pain in 32 (74.4%) patients followed by headache in 19 (44.2%). The most common trigger factor was upper respiratory tract infection detected in 13 (30.2%) patients followed by urinary infection in 12 (27.9%). The most associated disorder was abdominal migraine in 5 (11.6%) patients. Conclusion: The presentation of CVS shares many similarities with migraine and thus the treatment options could be potentially similar.

Cyclic Vomiting Syndrome and Migraine in Children

Cyclic vomiting syndrome (CVS) is an episodic nausea and non-bilious vomiting disorder characterized by recurrent stereotypic symptoms with disease-free intervals. CVS in children is associated with a high prevalence of migraine, and is commonly considered a precursor to migraine. This study aimed to investigate the clinical manifestations of pediatric CVS and its prognosis, and to clarify its relationship with the risk of migraine development in children. The clinical features of children diagnosed with CVS before the age of 18 years at the designated hospital were retrospectively studied over the past 30 years (1976-2006) based on the Rome III or ICHD II criteria. Clinical evaluations, including age of onset, sex, family history, symptoms and duration during attacks, frequency, trigger events, electroencephalogram, treatment and subsequent development of migraine were assessed from chart records and telephone interviews. Thirty-five children (17 males and 18 females) were enrolled. Their age of onset ranged from 2 to 17 years (mean, 6.8 ± 3.1 years) and frequency of attacks ranged from once to 36 times per year (mean, 8.2 ± 7.6 times). Duration of symptoms during each attack ranged from 1 to 45 days (mean, 5.9 ± 7.3 days). Of 20 children assessed for migraine development, seven subsequently developed typical migraine symptoms. There was younger onset age in the migraine-positive subgroup (5 ± 1.7 years) than in the migraine-negative subgroup (8.9 ± 3 years; p = 0.001). Co-morbid headache during CVS attack was also more evident in the migraine-positive subgroup (28.6%vs. 0%). Results of the study show that younger onset age and headache during CVS attacks may have increased risk of migraine development. Large-scale prospective studies are warranted to further clarify the relationship between CVS and migraine.

A survey of emergency department use in patients with cyclic vomiting syndrome

BackgroundCyclic vomiting syndrome (CVS), a chronic disorder characterized by recurrent episodes of vomiting, is frequently unrecognized and is associated with high utilization of emergency department (ED) services.MethodsA web-based survey was posted on the Cyclic Vomiting Syndrome Association (CVSA) website to assess utilization of ED services in patients with CVS.ResultsOf 251 respondents, 104 (41.4%) were adult CVS patients and 147 (58.6%) were caregivers of pediatric and adult patients. In the adult group, the median number of ED visits for CVS symptoms was 15(range 1 - 200), with a median of 7 ED visits prior to a diagnosis of CVS (range 0 - 150). In the caregiver group, the median number of ED visits was 10 (range 1 - 175) and the median number of ED visits prior to a diagnosis of CVS was 5 (range 0 - 65). CVS was not diagnosed in the ED in 89/104 (93%) adults and 119/147 (93%) patients in the caregiver group. CVS was not recognized in the ED in 84/95 (88%) of adults and 97/122 (80%) of patients in the caregiver group, despite an established diagnosis of CVS.ConclusionThere is a sub-group of adult and pediatric CVS patients who are high utilizers of ED services and CVS is not recognized in the ED in the majority of patients. Improved efforts to educate ED physicians are indicated to optimize treatment of patients with CVS and to decrease potential overuse of ED services.

Are pediatric and adult‐onset cyclic vomiting syndrome (CVS) biologically different conditions? Relationship of adult‐onset CVS with the migraine and pediatric CVS‐associated common mtDNA polymorphisms 16519T and 3010A

Pediatric cyclic vomiting syndrome (CVS) is associated with a high prevalence of co-morbid migraine and other functional disorders, and with two adult migraine-associated mitochondrial DNA (mtDNA) polymorphisms: 16519T and 3010A. These potential associations have not been studied in adult CVS. The objective of this study is to determine the prevalence of 16519T and 3010A mtDNA polymorphisms and other functional disorders in adult CVS patients. Adults with CVS recruited from the University of Kansas meeting Rome III criteria and a population control group completed a self-reported survey that included questions relating to the diagnostic criteria for several functional disorders. DNA was isolated from blood or saliva and genotyping was performed by standard methodologies. Adult CVS subjects, compared to controls, had significantly more symptoms consistent with several other functional disorders. 16519T was present in 22/31 cases (71%) of child-onset (<12 years) and 9/31 (29%) cases of adult-onset (18+ years) CVS (P = 0.01), vs 27% of controls. Among subjects with 16519T, 3010A was present in 30% of child-onset vs 0% of adult-onset CVS (P = 0.05) and 2% of controls. The conclusions drawn were: (i) unlike pediatric CVS, adult CVS is not associated with the 16519T and 3010A mtDNA polymorphisms, suggesting a degree of genetic distinction and (ii) similar to the pediatric setting, adult CVS is associated with a substantial burden of co-morbid functional disorders.

T1144 Health Related Quality of Life in Pediatric Cyclic Vomiting Syndrome (CVS)

T1144 Health Related Quality of Life in Pediatric Cyclic Vomiting Syndrome (CVS)

The Incidence of Cyclic Vomiting Syndrome in Children: Population-Based Study.

Cyclic vomiting syndrome (CVS) is characterized by severe recurrent episodes of vomiting in an otherwise healthy child. Currently, there is no population data on the incidence of CVS. The aim of this study was to determine the incidence of CVS and to define the clinical characteristics of the condition at diagnosis. Each pediatrician on the island of Ireland was surveyed on a monthly basis from January 1, 2005 to December 31, 2005 by the Irish Pediatric Surveillance Unit (IPSU) and was asked to report any incident cases of CVS according to the criteria outlined by the First International Symposium on CVS. Subsequently, data on demographics and clinical features were collected anonymously from the reporting pediatricians. Eighty-nine percent (1,647 of 1,848) of the surveillance cards were returned, reporting 41 valid cases of CVS. The incidence of CVS in Ireland was 3.15/100,000 children per annum for 2005 (95% confidence interval [CI] 2.19-4.11). The median age at diagnosis of CVS was 7.42 yr (range 1.8-15 yr). The median age at onset of CVS was 4 yr (range 0.5-14 yr) with 46% (19 of 41) of children having an onset at or before the age of 3 yr. The median number of episodes of CVS per child per year was eight (range 3-52); the median duration of an episode was 24 h (range 1 h to 5 days). Of school-age children, 85% (22 of 26) had missed school in the previous year due to CVS and 44% (18 of 41) were admitted to hospital for supportive treatment or investigation of CVS. CVS is a relatively common condition in pediatric patients, with an incidence comparable to other major gastrointestinal diseases of childhood, such as Crohn's disease. The onset of pediatric CVS is generally early in childhood and this disease causes significant morbidity in the majority of those affected.

Treatment of cyclic vomiting syndrome

Cyclic vomiting syndrome (CVS) is a relatively rare but highly incapacitating disorder. It is seen both in children and adults, although classically it has been perceived as a pediatric gastrointestinal disorder. Recent studies have demonstrated that this disorder indeed can be seen in adults and is highly disabling. Although classically associated with migraine headaches in the pediatric form, this relationship is less well established in adults. This has major implications for management in that traditionally, one of the major avenues for treatment of pediatric CVS has been antimigraine drugs. An additional factor that obscures a review of CVS treatment is the fact that because of its relative rarity, no randomized controlled trials (RCTs) have been performed. In the absence of RCTs, it is difficult to make definitive recommendations regarding treatment. The literature to date consists of case reports and open-ended case series. However, despite these limitations, it is the goal of this article to present in a comprehensive manner the options available for the treatment of CVS. Recognizing the limitations in the literature, it is clear that a number of treatment strategies that can often prove effective for the treatment of these complicated and often-challenging patients are available. Treatment is divided between acute intervention, when a patient is actively and severely vomiting, and prophylactic treatment for patients in their "interictal" phase, the goal of which is reducing frequency and intensity of subsequent episodes. Finally, we are beginning to identify possible mechanisms of the cause of CVS. Once these are better understood, this will provide the basis for further improvement in treatment.

Treatment of cyclic vomiting syndrome

Cyclic vomiting syndrome (CVS) is a relatively rare but highly incapacitating disorder. It is seen both in children and adults, although classically it has been perceived as a pediatric gastrointestinal disorder. Recent studies have demonstrated that this disorder indeed can be seen in adults and is highly disabling. Although classically associated with migraine headaches in the pediatric form, this relationship is less well established in adults. This has major implications for management in that traditionally, one of the major avenues for treatment of pediatric CVS has been antimigraine drugs. An additional factor that obscures a review of CVS treatment is the fact that because of its relative rarity, no randomized controlled trials (RCTs) have been performed. In the absence of RCTs, it is difficult to make definitive recommendations regarding treatment. The literature to date consists of case reports and open-ended case series. However, despite these limitations, it is the goal of this article to present in a comprehensive manner the options available for the treatment of CVS. Recognizing the limitations in the literature, it is clear that a number of treatment strategies that can often prove effective for the treatment of these complicated and often-challenging patients are available. Treatment is divided between acute intervention, when a patient is actively and severely vomiting, and prophylactic treatment for patients in their “interictal” phase, the goal of which is reducing frequency and intensity of subsequent episodes. Finally, we are beginning to identify possible mechanisms of the cause of CVS. Once these are better understood, this will provide the basis for further improvement in treatment.