Evaluation of neurocardiac signals in pediatric patients with cyclic vomiting syndrome through power spectral analysis of heart rate variability

Is Postoperative Pain Associated With Nausea and Vomiting Following Orthognathic Surgery?

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common adverse side-effect following orthognathic surgery, with pain potentially contributing as a risk factor.

PURPOSE

The study's purpose was to measure the association between postoperative pain and PONV.

STUDY DESIGN, SETTING, SAMPLE

This prospective cohort study involved patients who underwent bimaxillary surgery at Erciyes University, Oral and Maxillofacial Surgery Hospital. Patients with a history of routine antiemetic use, pregnancy, breastfeeding, morbid obesity, cardiac dysrhythmia, mental retardation, or psychiatric illness were excluded.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

The predictor variable was postoperative pain, which was measured using a 100-mm visual analogue scale (VAS). VAS scores were documented at the 30-minute postoperative mark (referred to as VAS1), and the mean of hourly VAS scores over the initial three postoperative hours (denoted as VAS2).

MAIN OUTCOME VARIABLE(S)

The primary outcome was the occurrence of PONV, defined as active vomiting, retching, or nausea leading to vomiting. The secondary outcome was the timing of PONV, categorized as early (within 6 hours), late (6-24 hours), and delayed (beyond 24 hours postoperatively).

COVARIATES

The study's covariates were age, sex, body mass index, Apfel risk scores, surgery duration, history of PONV or motion sickness, and smoking status.

ANALYSES

Descriptive statistics and χ2 tests were used for data analysis, with statistical significance set at P value < .05.

RESULTS

The sample was composed of 86 subjects with a median age of 20 years (range: 18-30 years), of which 37.2% were male. The frequency of PONV was 50%. Postoperative pain, as measured by VAS scores, was significantly higher in the PONV group compared to the non-PONV group. The median VAS1 score was 60.0 (PONV group, range 40-90) versus 50.0 (non-PONV, range 0-90) (P = .041); for VAS2, it was 60.0 (PONV, range 40-80) compared to 40.0 (non-PONV, range 30-60) (P < .001).

CONCLUSIONS AND RELEVANCE

The frequency of PONV observed in patients undergoing bimaxillary surgery is substantial, necessitating the identification and management of risk factors to enhance perioperative care and patient outcomes. By improving PONV management and addressing postoperative pain, health-care providers can enhance the perioperative experience and patient outcomes in bimaxillary surgery.

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.

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.

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.

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.

Traumatic stress and the autonomic brain-gut connection in development: Polyvagal Theory as an integrative framework for psychosocial and gastrointestinal pathology

A range of psychiatric disorders such as anxiety, depression, and post-traumatic stress disorder frequently co-occur with functional gastrointestinal (GI) disorders. Risk of these pathologies is particularly high in those with a history of trauma, abuse, and chronic stress. These scientific findings and rising awareness within the healthcare profession give rise to a need for an integrative framework to understand the developmental mechanisms that give rise to these observations. In this paper, we introduce a plausible explanatory framework, based on the Polyvagal Theory (Porges, Psychophysiology, 32, 301-318, 1995; Porges, International Journal of Psychophysiology, 42, 123-146, 2001; Porges, Biological Psychology, 74, 116-143, 2007), which describes how evolution impacted the structure and function of the autonomic nervous system (ANS). The Polyvagal Theory provides organizing principles for understanding the development of adaptive diversity in homeostatic, threat-response, and psychosocial functions that contribute to pathology. Using these principles, we outline possible mechanisms that promote and maintain socioemotional and GI dysfunction and review their implications for therapeutic targets.

Managing cyclic vomiting syndrome in children: beyond the guidelines

Cyclic vomiting syndrome (CVS) in children is characterized by frequent hospitalizations, multiple comorbidities, and poor quality of life. In the absence of robust data, the treatment of CVS remains largely empiric starting with the 2008 NASPGHAN Consensus Statement recommendations of cyproheptadine for children < 5 years of age and amitriptyline for those ≥ 5 years with propranolol serving as the second-line agent. Comprehensive management begins with lifestyle alterations, and extends to medications, supplements, and stress reduction therapies. Standard drug therapy is organized by the four phases of the illness: (1) interictal (preventative medications and mitochondrial supplements), (2) prodromal (abortive agents), (3) vomiting (fluids/energy substrates, antiemetics, analgesics, and sedatives) and (4) recovery (supportive care and nutrition). Because the response to treatment is heterogeneous, clinicians often trial several different preventative strategies including NK1 antagonists, cautious titration of amitriptyline to higher doses, anticonvulsants, Ca²⁺-channel blockers, and other TCA antidepressants. When the child remains refractory to treatment, reconsideration of possible missed diagnoses and further mono- or combination therapy and psychotherapy can be guided by accompanying comorbidities (especially anxiety), specific subphenotype, and when available, genotype. For hospital intervention, IV fluids with 10% dextrose, antiemetics, and analgesics can lessen symptoms while effective sedation in some instances can truncate severe episodes.

CONCLUSION

Although management of CVS remains challenging to the clinician, approaches based upon recent literature and accumulated experience with subgroups of patients has led to improved treatment of the refractory and hospitalized patient. What is Known: • Cyclic vomiting syndrome is a complex disorder that remains challenging to manage. • Previous therapy has been guided by the NASPGHAN Consensus Statement of 2008. What is New: • New prophylactic approaches include NK1 antagonists and higher dosages of amitriptyline. • Strategies based upon comorbidities and subphenotype are helpful in refractory patients.

[Cyclic vomiting syndrome in children]

Cyclic vomiting syndrome (CVS) is a misrecognized and probably underdiagnosed disease that can affect up to 1.9% of the pediatric population and can occupy 15% of these children's time. It is characterized by acute attacks of vomiting, occurring with such a strict frequency that some parents can predict the date of their child's next attack. The pathophysiology of CVS is unclear, although the literature recognizes a common origin with migraine headaches, which has the same acute and prophylactic treatment. CVS is now included in the larger group of diseases called "episodic symptoms related to migraine" previously known as "childhood periodic syndromes." To distinguish between real CVS and other differential diagnoses can challenge the clinician. Additional investigations must be considered in accordance with the clinical presentation. Appropriate management of CVS should lead to an improvement in quality of life and school attendance.

Anxiety and physiological responses to the Trier Social Stress Test for Children in adolescents with cyclic vomiting syndrome

This study compared anxiety and physiological responses during the Trier Social Stress Test for Children (TSST-C) in adolescents. 38 subjects (26 females) were enrolled: 11 cyclic vomiting syndrome (CVS), 11 anxiety, and 16 controls. Salivary cortisol, α-amylase and heart rate variability (HRV) were assessed during the TSST-C. Anxiety was measured by the Screen for Childhood Anxiety Related Emotional Disorders (SCARED), Anxiety Disorders Interview Schedule, and State-Trait Anxiety Inventory for Children (STAI-C). 11 anxiety and 7 CVS subjects had ≥1 anxiety disorder. 82% in the anxiety and CVS groups met criteria for an anxiety disorder on the SCARED. Combining groups, cortisol increased from baseline to recovery during the TSST-C (p=0.0004) and the stressor to recovery (p=0.005). α-amylase did not differ during the TSST-C for the total sample, but increased for anxiety compared to controls from baseline to recovery (p=0.01). HRV decreased during the stressor (p=0.0001) and increased at recovery (p=0.004). No associations were found between biomarkers and trait anxiety. Associations were found between baseline HRV and pre-test state anxiety (r=-0.406, p=0.012) and between recovery HRV and post-test state anxiety (r=-0.501, p=0.002) for the total sample. Anxiety is prevalent in CVS warranting screening. HRV may serve as a biomarker for evaluating stress as a potential trigger for CVS episodes. State but not trait anxiety was associated with changes in HRV, suggesting acute anxiety may be more relevant in linking stress and CVS episodes.

Cerebral vasospasm and wernicke encephalopathy secondary to adult cyclic vomiting syndrome: the role of magnesium

Background

Magnesium has a regulatory role in the excitability of cell membranes, and is also a cofactor in the phosphorylation of thiamine. Hypomagnesemia has been associated with coronary vasospasm, but its role in cerebrovascular pathology is controversial, and cerebral vasospasm exclusively attributable to hypomagnesemia has not been reported in humans.

Case presentation

We report the case of a 51-year-old man in whom uncontrollable vomiting, treatment with omeprazole and thiazide, and renal impairment lead to a severe hypomagnesemia (magnesium below the level of detection in blood tests), which secondarily caused Wernicke’s encephalopathy and vasospasm in multiple cerebral arteries (seen with cerebral angiography and CT angiography) that presented with a complete right hemisphere neurological deficit. These disturbances completely resolved when magnesium levels were normalized and subsequent neuroimaging tests confirmed the resolution of angiographic changes.

Conclusion

Our case suggests that hypomagnesemia should be considered in the differential diagnosis of patients with neurological symptoms and predisposing causes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-016-0660-x) contains supplementary material, which is available to authorized users.

Functional Nausea in Children

Chronic nausea is a highly prevalent, bothersome, and difficult-to-treat symptom among adolescents. When chronic nausea presents as the predominant symptom and is not associated with any underlying disease, it may be considered a functional gastrointestinal disorder and named "functional nausea." The clinical features of functional nausea and its association with comorbid conditions provide clues to the underlying pathophysiological mechanisms. These may include gastrointestinal motor and sensory disturbances, autonomic imbalance, altered central nervous system pathways, or a combination of these. This review summarizes the current knowledge on mechanisms and treatment strategies for chronic, functional nausea in children.

Anxiety Measures Predict Health-Related Quality of Life in Children and Adolescents with Cyclic Vomiting Syndrome

OBJECTIVE

To evaluate the relationship between anxiety and health-related quality of life (HRQoL) in children and adolescents with cyclic vomiting syndrome (CVS).

STUDY DESIGN

Forty children aged 8-18 years diagnosed with CVS and 40 parents completed the Screen for Child Anxiety Related Emotional Disorders (SCARED) and the child and parent forms of the Pediatric Quality of Life Generic Core Scale, a measure of HRQoL.

RESULTS

Eleven of the 40 children (27%) by self-report and 6 of 40 (15%) by parent-proxy report met the clinical cutoff for an anxiety disorder on the SCARED. Parent and child SCARED ratings were moderately correlated (intraclass correlation coefficient 0.68; P < .001). Child-rated HRQoL (mean ± SD, 74.3 ± 15.2) and parent-rated HRQoL (mean, 72.1 ± 14.6) were lower than healthy norms (P < .001). Disease severity (mean duration of CVS episodes, 3 ± 2.4 days), annual frequency of CVS episodes (mean, 8.2 ± 15.3), chronicity of CVS (mean, 5.8 ± 3.4 years), and delay in diagnosis (mean, 2.4 ± 1.9 years) were not associated with child-reported HRQoL; however, child SCARED scores accounted for approximately 50% of the variance in child-reported HRQoL (adjusted R(2) = 0.49; df = 1, 38; P < .001).

CONCLUSION

Children and adolescents with CVS appear to be at increased risk for anxiety. Anxiety symptoms are a stronger predictor of HRQoL than disease characteristics in children and adolescents with CVS. Assessment and treatment of anxiety in children and adolescents with CVS may have a positive impact on HRQoL.

NextGen nuclear DNA sequencing in cyclic vomiting syndrome reveals a significant association with the stress-induced calcium channel (RYR2)

BACKGROUND

Cyclic vomiting syndrome (CVS) is a common, frequently disabling, 'functional' condition characterized by recurring, stereotypical attacks of intense nausea, vomiting, and lethargy, with the essential absence of these symptoms between episodes. Although the pathogenesis of CVS is yet unexplained, evidence has accumulated which suggest pathogenic roles for stress-related, autonomic, neuroendocrine, and mitochondrial factors. The objective of this pilot study was to elucidate mechanism(s) by identifying genes involved in the presumed multifactorial pathogenesis of CVS.

METHODS

In this pilot study, DNA from 75 unrelated CVS cases and 60 healthy controls were assayed by Courtagen Life Science's next-generation sequencing platform (nucSEEK(™) ), including over 1100 nuclear-encoded genes involved with mitochondria, metabolism, or ion channels. Significant sequence variants were defined as evolutionary conservation at least to Xenopus (frog) per the UCSC Genome Browser.

KEY RESULTS

The RYR2 gene, encoding a stress-induced calcium channel present in many neurons, was the only gene demonstrating a statistically significant difference in the proportion of conserved sequence variants among the groups (18/75 CVS, 24%, vs 3/60 controls, 5%; p = 0.0018, OR = 6.0, 95% CI = 1.7-22).

CONCLUSIONS & INFERENCES

We propose a mechanism in which RYR2 sequence variants result in aberrant stress-induced calcium release into the mitochondria of autonomic neurons, resulting in an increased risk to develop autonomic/functional disease such as CVS, and related conditions such as migraine and gut dysmotility. This model incorporates the existing hypotheses regarding CVS pathogenesis into a cohesive mechanism, and might have treatment implications.

Relationship among nausea, anxiety, and orthostatic symptoms in pediatric patients with chronic unexplained nausea

This study evaluated the relationship among nausea, anxiety, and orthostatic symptoms in pediatric patients with chronic unexplained nausea. We enrolled 48 patients (36 females) aged 15 ± 2 years. Patients completed the Nausea Profile, State-Trait Anxiety Inventory for Children and underwent 70° head upright tilt testing (HUT) to assess for orthostatic intolerance (OI) and measure heart rate variability (HRV). We found nausea to be significantly associated with trait anxiety, including total nausea score (r = 0.71, p < 0.01) and 3 subscales: somatic (r = 0.64, p < 0.01), gastrointestinal (r = 0.48, p = 0.01), and emotional (r = 0.74, p < 0.01). Nausea was positively associated with state anxiety, total nausea (r = 0.55, p < 0.01), somatic (r = 0.48, p < .01), gastrointestinal (r = .30, p < .05), and emotional (r = .64, p < .01) subscales. Within 10 min of HUT, 27 patients tested normal and 21 demonstrated OI. After 45 min of HUT, only 13 patients (27%) remained normal. Nausea reported on the Nausea Profile before HUT was associated with OI measured at 10 min of tilt (nausea total r = 0.35, p < 0.05; nausea emotional subscale r = 0.40, p < 0.01) and lower HRV at 10 min of HUT (F = 6.39, p = 0.01). We conclude that nausea is associated with both anxiety symptoms and OI. The finding of decreased HRV suggests an underlying problem in autonomic nervous system function in children and adolescents with chronic unexplained nausea.

A curable and probably often-overlooked cause of cyclic vomiting syndrome

Cyclic vomiting syndrome is a disorder of many causes. The major challenge is to label the disorder as idiopathic or primary only when all possible etiologies, particularly those that can be specifically treated, have been ruled out. In retrospect, our patient had subtle prenatal and early postnatal radiological findings supportive of a urological cause for his symptoms, the importance of which was initially missed. It would probably be wise to include an abdominal ultrasound examination (looking for hydronephrosis) in the "must-do" battery of tests for the investigation of all cases of recurrent cyclic vomiting without apparent cause. Otherwise, it seems likely that many cases of ureteropelvic junction obstruction will be missed, cases in which surgical intervention can be curative.

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.

Pathology of emesis: its autonomic basis

Vagal and non-vagal pathways as well as several brainstem nuclei participate in vomiting in response to different emetic stimuli. Autonomic pathways involved in nausea are less well understood. Numerous gastrointestinal disorders with prominent nausea and vomiting including gastroparesis, cyclic vomiting syndrome, and motion sickness have associated autonomic nervous system dysfunction. Autonomic disturbances are also seen with non-gastrointestinal diseases with gut manifestations such as migraine headaches, orthostatic intolerance, and familial dysautonomia. Stimulation of emetic pathways involves activation of a range of receptor subtypes. Agents acting on these receptors form the basis for antiemetic therapies. Chemotherapy-induced nausea and vomiting, a prevalent and severe consequence of anticancer treatment, is preventable in many instances by agents acting on the autonomic nervous system. Likewise, non-medication therapies may act in part via modulation of some of these same autonomic pathways.

The management of cyclic vomiting syndrome: a systematic review

Cyclic vomiting syndrome (CVS) is a rare abnormality of the neuroendocrine system that affects 2% of children. It is a frequently missed diagnosis in the emergency department and may require a number of emergency department visits before the diagnosis is made. The objectives of this review are to identify the clinical features that suggest a diagnosis of CVS and to review the literature on its management. The MEDLINE and EMBASE databases were searched from January 1948 to October 2011 using the keywords 'Cyclic' or 'Vomiting'. Papers were excluded if they did not follow the consensus guidelines or if they were case reports. This review analysed 1093 cases of cyclic vomiting in 25 papers that fulfilled the inclusion criteria. All except one paper were retrospective studies. The size of these cohort studies ranged from three to 181 patients, with a mean patient size of 29. This review found that over 40% of patients have headaches/migraines, with associated anxiety and depression in ≈ 30% of cases. There is a family history of headaches/migraines in 38.9%, and this association was much stronger in the adult CVS cohort compared with the paediatric cohort. Compared with paediatric CVS, adults have a longer duration of attacks and they occur more frequently (5.9 vs. 3.4 days, 14.4 vs. 9.6 episodes/year). Limited data are available on the treatment of the acute phase of CVS, but in adults, sumatriptan has been shown to be effective. For prophylactic treatment, tricyclics are effective in both adult and paediatric CVS, with a clinical response in 75.5 and 67.6% of patients, respectively, in nonplacebo-controlled cohort studies. Furthermore, propranolol has been shown to be useful in children. CVS is an intractable illness with a major impact on the patient's quality of life. There is a long duration between the onset of symptoms and the diagnosis of the condition. There is a high association with headaches/migraines and anxiety/depression. The symptoms are more severe in adult-onset CVS. Tricyclic antidepressants have good efficacy in reducing the frequency/duration or the intensity of attacks. There is limited evidence on the acute management of CVS.

Cyclic vomiting syndrome in 28 patients: demographics, features and outcomes

INTRODUCTION

Cyclic vomiting syndrome (CVS) is a condition characterized by recurrent, stereotyped, attacks of intense nausea and intractable vomiting with no identifiable cause. The diagnosis is made according to the Rome III criteria; however, the condition remains a heterogenous group of symptoms and few studies have analysed patient-reported features in detail. Tricyclic antidepressants may benefit some patients, but there are no data on the long-term outcomes of this condition.

METHODS

This is a retrospective cohort study of all patients treated at two London teaching hospitals between 1994 and 2011. Information was obtained by means of inpatient case notes, clinic letters and telephone interviews using a standardized questionnaire.

RESULTS

Twenty-eight patients were identified, 17 with adult-onset CVS and 11 with childhood-onset CVS. In the adult-onset CVS cohort, the average age of onset was 30 years; the prevalence of headache was 57.1% and anxiety/depression 21.7%. Vomiting attacks occurred on average 10 times a year with a mean duration of 55.3 h. In the childhood-onset CVS cohort, the average age of onset was 5 years and the prevalence of headaches was 44.4%. Vomiting attacks occurred on average 25.5 times a year with a mean duration of 54.5 h. During acute attacks, patients rated morphine-based medications as the most efficacious. Overall, 65.4% of our patients were not treated with long-term prophylactic medications and, of these, 42.1% felt that their symptoms had improved and 26.3% reported complete resolution.

CONCLUSION

CVS is a debilitating illness with frequent attacks of prolonged duration. There is a high association with anxiety/depression as well as headaches. Antimigraine medication, β-blockers and antiepileptic treatment may be successful at attenuating attacks; however, in this long-term study, the prognosis of patients not treated with these medications was also good. Overall, 61.9% of patients showed a gradual improvement in symptoms and 23.8% had complete resolution after a mean of 7 years.

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.

Autonomic nerve function in adult patients with cyclic vomiting syndrome

BACKGROUND

Cyclic vomiting syndrome (CVS) in adults is a disorder characterized by recurrent and stereotypic episodes of severe nausea and vomiting separated by symptom-free periods. Autonomic dysfunction has been a postulated mechanism for the pathogenesis of this disorder in children but has not been explored in adults.

METHODS

Our goals were to investigate autonomic nerve function in adult patients with CVS. The sympathetic nervous system was evaluated through postural changes in heart rate and blood pressure and sympathetic skin response in the hand and foot. The parasympathetic nervous system was tested through heart rate response to deep breathing [expiration/inspiration (E/I)], Valsalva and postural indices (30 : 15 ratio). All patients had a 4-h standard isotope labeled egg beater meal gastric emptying test (GET).

KEY RESULTS

Twenty-two adult (18 female), mean age 35 ± 11 (range 19-61 years), who met Rome III criteria for CVS were included. History of migraine headache was reported in three patients. Five (23%) had pediatric onset. Of 21 patients who completed the test, nine patients had 21 abnormalities detected in their autonomic nerve testing profile and the remaining 12 had normal autonomic function results. Orthostatic tachycardia was observed in two (mean heart rate increase 39 beats min(-1)) and a decline in blood pressure (BP) in three patients (mean BP drop 30/14 mmHg). Parasympathetic abnormalities were elicited in six patients with an abnormal response to deep breathing and E/I index <1.25. Sympathetic nerve dysfunction was reported in seven patients with absent sympathetic skin response in the foot and/or hand. Twelve (57%) of CVS group had rapid GET (<50% retention at 1 h). The frequency of abnormal autonomic nerve function was not significantly higher in rapid GET subgroup.

CONCLUSIONS & INFERENCES

(i) Autonomic nerve dysfunction is common in adult CVS patients, being observed in 43% of our cohort; (ii) Sympathetic abnormalities dominate; and (iii) Rapid gastric emptying, present in 57% of patients, did not correlate with autonomic testing results. These new data provide more insight into the pathophysiology of CVS in adults and help explain the spectrum of clinical manifestations observed in this entity.

Breaking the cycle: cognitive behavioral therapy and biofeedback training in a case of cyclic vomiting syndrome

The present article presents a case of cognitive behavioral therapy (CBT) along with heart rate variability (HRV) biofeedback training for the treatment of a medication unresponsive 13-year-old boy with cyclic vomiting syndrome (CVS). CVS is characterized by recurring stereotypic episodes of vomiting, interspersed with asymptomatic periods. Triggers for vomiting include anticipatory anxiety related to school examinations, family conflicts, and birthday parties as well as infectious diseases, and certain foods. Current treatment design addressed two pivotal etiological factors: autonomic dysregulation and anticipatory anxiety. Treatment outcome suggests that vomiting episodes may be successfully prevented by aiding the patient to identify and manage precipitant psychological stressors, to regulate HRV patterns, and gain a renewed sense of bodily control and self-efficacy. Further research is suggested using a controlled study with pre- and post-behavioral and stress measures to evaluate the effectiveness of CBT and biofeedback training compared to pharmacotherapy and placebo.

Posterior reversible encephalopathy syndrome in a child with cyclical vomiting and hypertension: a case report

Introduction

Posterior reversible encephalopathy syndrome is characterized by headache, nausea and vomiting, seizures and visual disturbances. It has certain characteristic radiological features, which allow diagnosis in the appropriate clinical setting and enable appropriate clinical therapy to be instituted.

Case presentation

A 10-year-old Caucasian girl who was hospitalized due to recurrent vomiting was diagnosed as having posterior reversible encephalopathy syndrome after an initial diagnosis of cyclical vomiting and hypertension was made.

Conclusion

Posterior reversible encephalopathy syndrome is a rare disorder in children. Early recognition of characteristic radiological features is key to the diagnosis as clinical symptoms may be non-specific or mimic other neurological illnesses. To the best of our knowledge this is the first case to report an association between posterior reversible encephalopathy syndrome, cyclical vomiting and hypertension. Furthermore, in this case, the resolution of the abnormalities found on magnetic resonance imaging over time did not appear to equate with clinical recovery.

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

BACKGROUND

Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder that is characterized by recurrent episodes of intense vomiting. There are several postulated mechanisms involved in its pathogenesis and one potential explanation for this disorder may be linked to autonomic dysfunction. The aim of our study was to evaluate autonomic nerve function in patients with CVS prospectively.

METHODS

We tested the sympathetic nervous system through postural changes in heart rate (HR) and blood pressure and the thermoregulatory sweat test. The parasympathetic nervous system was tested through the HR response to deep breathing (R-R variability on EKG).

KEY RESULTS

A total of 20 patients who met Rome III criteria for CVS, 14 (70%) women and 6 (30%) men, and 20 controls were enrolled in the study. A total of 17 (85%) CVS subjects and 2 (10%) controls had abnormalities on thermoregulatory sweat testing (P < 0.001). A total of 7 (35%) patients and one control subject had evidence of postural tachycardia (P = 0.04) with an increase in HR > 30 on standing. Of the subjects, 18 (90%) had either abnormal sudomotor function or postural tachycardia or both. The HR response to deep breathing was normal in 19 (95%) subjects with CVS and 18 (95%) controls.

CONCLUSIONS & INFERENCES

The results of this study suggest that the majority of subjects (90%) with CVS have impairment of the sympathetic nervous system with postural tachycardia and/or sudomotor dysfunction while parasympathetic nerve function appears to be intact. These findings of dysautonomia in CVS have implications in both the diagnosis and treatment of these patients.

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

Background

Cyclic 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.

Methods

A web-based survey was posted on the Cyclic Vomiting Syndrome Association (CVSA) website to assess utilization of ED services in patients with CVS.

Results

Of 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.

Conclusion

There 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.

Patients with cyclic vomiting pattern and diabetic gastropathy have more migraines, abnormal electrogastrograms, and gastric emptying

OBJECTIVE

Some patients with diabetic gastroparesis exhibit cyclical symptoms. The purpose of this work was to study the subset of patients with cyclic vomiting characteristics, described as a cyclic vomiting pattern, in a population of patients with symptoms of diabetic gastroparesis.

MATERIAL AND METHODS

Sixty-seven patients with symptoms of diabetic gastroparesis were investigated. The patients were divided into two groups based on the presence or lack of cyclic symptoms, and stratified by demographics, medical history, hemoglobin A1C, total symptom score (TSS), standardized gastric emptying test (GET), and electrogastrography (EGG).

RESULTS

Of these 67 patients, 38 (56%) had cyclic symptoms. The two groups were similar in age, gender, illness duration, insulin use, hemoglobin A1C values, and TSS. There were noteworthy differences regarding migraine headache (47.4% versus 20.7%, p=0.02), gastric emptying study (GES) at 1 h (84.1% versus 59.9%, p=0.02), EGG frequency (4.9 versus 3.6 cpm, p=0.05), and gastric emptying area under the curve (p=0.06).

CONCLUSIONS

A sizeable percentage of patients have cyclic symptom patterns and have a higher incidence of migraine headaches, a greater delay in gastric emptying, and more abnormal EGG frequencies than other patients with symptoms of diabetic gastroparesis.

Cyclic vomiting syndrome in adults

Cyclic vomiting syndrome (CVS) was initially described in children but can occur in all age groups. Cyclic vomiting syndrome is increasingly recognized in adults. However, the lack of awareness of CVS in adults has led to small numbers of diagnosed patients and a paucity of published data on the causes, diagnosis and management of CVS in adults. This article is a state-of-knowledge overview on CVS in adults and is intended to provide a framework for management and further investigations into CVS in adults.

Cyclic vomiting syndrome: what a gastroenterologist needs to know

BACKGROUND

CVS (cyclic vomiting syndrome) is a functional disorder that may occur in any age group of patients. In the past the disorder was considered to be fairly uncommon of unknown etiology. Treatment has generally been based on anecdotal reports.

METHODS

Literature review was performed based on internet/Medline search as of April 2006.

RESULTS

CVS is much more common than previously thought, especially in adults and is commonly associated with migraine headaches and sharing many of its characteristic features. Genetic association with mitochondrial DNA has been recognized with CVS. Prompt diagnosis is essential in order to prevent the significant morbidity associated with CVS. It is mandatory to rule out certain life-threatening disorders that can mimic CVS. Treatment options are based on the particular phase of the syndrome in which a patient is in and carried out in a systematic manner.

CONCLUSION

Expert consensus is that CVS is a distinct disorder and is a part of the migraine spectrum (migraine headaches, CVS, and abdominal migraines). Once patients are properly diagnosed, treatment is highly effective. Because of renewed interest in CVS since the 1990's, many more patients in all age groups are being recognized who suffer from this disabling disorder. An increase in basic science and clinical research in CVS will hopefully lead to better patient outcomes.

Autonomic abnormalities in cyclic vomiting syndrome

BACKGROUND

Although cyclic vomiting syndrome (CVS) is associated with migraine, and migraine in turn is associated with orthostatic tachycardia, few studies have explored the association of CVS and autonomic dysfunction. We describe the results of autonomic testing in 6 children with characteristic CVS.

PATIENTS AND METHODS

All patients fully met the established criteria for the diagnosis of CVS, were well hydrated, and were beyond their episode of vomiting. We performed 3 tests of cardiovascular function and 1 sudomotor test, using standard previously published methods.

RESULTS

The findings were surprisingly uniform, with normal cardiovascular responses to deep breathing and to the Valsalva maneuver in all patients, a significant increase in heart rate (>30 beats per minute) with tilt testing, and a vasodepressor tendency in 2 patients. Interestingly, abdominal pain occurred at blood pressure nadir in both these patients and in a third patient without the vasodepressor findings but who described syncope clinically. Sudomotor test results were abnormal in all 6 patients, with reduced responses in 5 of 6 and exaggerated responses in the 6th. All 6 patients reported a personal or family history of migraine headaches.

CONCLUSIONS

CVS is associated with remarkably uniform primarily sympathetic autonomic dysfunction, affecting mainly the vasomotor and sudomotor systems, and compatible with an underlying autonomic neuropathy. The occurrence of symptoms during tilt testing in half the patients suggests that these findings may play a true pathophysiologic role. A vagally modulated sympathetic effect is postulated as the best mechanistic model to account for all current physiologic data on cyclic vomiting and gastroparesis.

Functional gastrointestinal disorders in migrainous children: efficacy of flunarizine

The aim of this study was to evaluate the prevalence of functional gastrointestinal disorders (FGIDs) in children with migraine headache and the effects of flunarizine on gastrointestinal manifestations. We studied 50 migrainous children (mean age 8.63 years). The clinical pattern and the diagnosis of FGIDs were obtained from structured questionnaires. All subjects underwent measurement of total gastric emptying time (TGEt) performed by real-time ultrasonography of the gastric antrum at baseline (T0). In the second part of the study, we evaluated 10 migrainous children (mean age 9.8 years) with associated FGIDs. In these 10 patients, repeated TGEt evaluation together with a detailed symptom history was obtained after 1 (T1) and 2 months (T2) of treatment with flunarizine. Control groups were composed of 10 migrainous children without FGIDs (mean age 9.2 years) and nine sex- and age-matched healthy children. Gastrointestinal disorders were present in 70% of the patients. Migrainous children with FGIDs had significantly (P < 0.01) more prolonged TGEt than subjects without FGIDs. Prior to therapy, all migrainous children with FGIDs had prolongation of TGEt compared with controls (P < 0.05). Patients on flunarizine had a significant decrease in TGEt at both 1 (P < 0.01) and 2 months (P = 0.002) of therapy. The mean frequency of abdominal pain per month was significantly (P < 0.001) reduced at T1 compared with T0. The mean frequency of vomiting per month was significantly decreased at T1 (P < 0.05) and even more so at T2 (P < 0.01). Finally, the mean frequency of headache per month was significantly reduced only at T2 (P < 0.05), whereas the mean duration of headache was significantly decreased at T1 (P < 0.01) with no difference between T1 and T2. Most children with migraine report FGIDs, associated with a delayed gastric emptying. Flunarizine decreases the frequency and duration of migrainous episodes as well as the gastrointestinal symptoms.

Diagnosing migraine in the pediatric population

Migraine in the pediatric population remains substantially underdiagnosed and undertreated. The recently revised International Classification of Headache Disorders is a step in the right direction to improve our diagnostic accuracy. This article reviews the practical diagnostic issues related to migraine in the pediatric population.

Pediatric autonomic disorders

The scope of pediatric autonomic disorders is not well recognized. The goal of this review is to increase awareness of the expanding spectrum of pediatric autonomic disorders by providing an overview of the autonomic nervous system, including the roles of its various components and its pervasive influence, as well as its intimate relationship with sensory function. To illustrate further the breadth and complexities of autonomic dysfunction, some pediatric disorders are described, concentrating on those that present at birth or appear in early childhood.

Cyclic vomiting syndrome plus

Cyclic vomiting syndrome, which is characterized by severe discrete episodes of nausea, vomiting, and lethargy, is a fairly common, disabling, predominately childhood condition. Approximately 25% of cases have coexisting neuromuscular disease manifestations (cyclic vomiting syndrome plus). To determine whether patients with cyclic vomiting syndrome and neuromuscular disease represent a distinct subentity within cyclic vomiting syndrome, a clinical interview was conducted regarding 80 randomly ascertained sufferers of cyclic vomiting syndrome from a disease association database. Cyclic vomiting syndrome plus and "cyclic vomiting syndrome minus," herein defined as the presence of at least two and zero neuromuscular disease manifestations, were present in 23 and 44 subjects, respectively. Neuromuscular disease manifestations, including cognitive disorders, skeletal myopathy, cranial nerve dysfunction, and seizure disorders, were found to statistically cluster together among the same subjects. In addition, subjects with cyclic vomiting syndrome with neuromuscular disease had an earlier age at onset for vomiting episodes and a three- to eightfold statistically increased prevalence for certain dysautonomia-related (migraine, chronic fatigue, neurovascular dystrophy) and constitutional (growth retardation and birth defects) disorders. However, subjects with cyclic vomiting syndrome with and without neuromuscular disease were equally likely to have a sibling affected with neuromuscular disease manifestations. We conclude that cyclic vomiting syndrome plus, although likely not genetically distinct from cyclic vomiting syndrome minus, represents a distinct phenotypic entity that predicts an earlier onset of disease and increased comorbidity with a distinct list of medical conditions, possibly owing to a higher degree of mitochondrial dysfunction.

Treatment options for cyclic vomiting syndrome

Since its initial description nearly two centuries ago, treatment of idiopathic cyclic vomiting syndrome (CVS) remains largely empiric because of its obscure pathogenesis and the paucity of controlled therapeutic trials. Despite these challenges, this report reviews open-label trials, retrospective case series, and upcoming consensus guidelines to update the treatment. The treatment approach to a patient with CVS should include consideration of lifestyle changes including avoidance of potential triggers, prophylactic drug therapy to prevent subsequent episodes, abortive and/or supportive care treatment during acute episodes, and support of the family. The mainstays of drug therapy include antimigraine, anti-emetic, and anticonvulsive medications used for prophylactic, abortive, and supportive therapy, with reported efficacies of between 40% and 90%. Prophylactic antimigraine and anticonvulsive agents are used to prevent episodes. Antimigraine triptans are used to abort episodes. Antiemetic agents can reduce the severity of episodes and are best used in conjunction with sedatives.

Cyclic Vomiting Syndrome in 41 adults: the illness, the patients, and problems of management

BACKGROUND

Cyclic Vomiting Syndrome (CVS) is a disorder characterized by recurrent, stereotypic episodes of incapacitating nausea, vomiting and other symptoms, separated by intervals of comparative wellness. This report describes the clinical features, co-morbidities and problems encountered in management of 41 adult patients who met the diagnostic criteria for CVS.

METHODS

This is a retrospective study of adults with CVS seen between 1994 and 2003. Follow-up data were obtained by mailed questionnaires.

RESULTS

Age of onset ranged from 2 to 49 years. The duration of CVS at the time of consultation ranged from less than 1 year to 49 years. CVS episodes were stereotypic in respect of their hours of onset, symptomatology and length. Ninety-three percent of patients had recognizable prodromes. Half of the patients experienced a constellation of symptoms consisting of CVS episodes, migraine diathesis, inter-episodic dyspeptic nausea and a history of panic attacks. Deterioration in the course of CVS is indicated by coalescence of episodes in time. The prognosis of CVS is favorable in the majority of patients.

CONCLUSION

CVS is a disabling disorder affecting adults as well as children. Because its occurrence in adults is little known, patients experience delayed or mis-diagnosis and ineffectual, sometimes inappropriately invasive management.

How do we diagnose migraine and childhood periodic syndromes?

Migraine remains substantially underdiagnosed and undertreated in the pediatric population. The incidence and prevalence of migraine in the pediatric population is not fully appreciated. The recently revised International Headache Society (IHS) criteria, The International Classification of Headache Disorders, is a step in the right direction to improving our diagnostic accuracy. These criteria are the basis for scientific studies and serve as the foundation for future research and clinical care. In this article, the diagnostic issues related to migraine and childhood periodic syndromes in the IHS 2004 revisions are reviewed.

Childhood periodic syndromes and migraine

Headache in the pediatric population remains substantially underdiagnosed and undertreated. The recently revised International Headache Society (IHS) criteria, The International Classification of Headache Disorders, is a step in the right direction to improve our diagnostic accuracy. In this article, the diagnostic issues related to childhood periodic syndromes and migraine in the IHS 2004 revisions are reviewed.

Maternal inheritance in cyclic vomiting syndrome

Cyclic vomiting syndrome (CVS), characterized by severe discrete episodes of nausea, vomiting, and lethargy, is a fairly common, disabling, predominately-childhood condition most often associated with migraine and dysautonomic features. Our group recently reported that children with CVS and additional neuromuscular disease manifestations demonstrate strong maternal inheritance of multiple disease manifestations and abnormal urine organic acids, suggesting the presence of predisposing mitochondrial DNA (mtDNA) sequence variants. In order to determine if maternal inheritance is present in CVS in general, a clinical interview was administered regarding 80 unrelated individuals with CVS ascertained randomly from the database of the Cyclic Vomiting Syndrome Association (CVSA). Disease manifestations consistent with potential mitochondrial dysfunction were far more common in matrilineal (sharing the same mtDNA sequence) versus in non-matrilineal relatives, including mothers versus fathers (P = 3 x 10(-9)) and maternal versus paternal grandmothers (P = 2 x 10(-6)). Maternal inheritance is suggested in 52% of the 23 subjects with two or more neuromuscular abnormalities ("CVS+") and in 54% of the 44 subjects without any neuromuscular abnormalities ("CVS-"). In both the CVS+ and CVS- sub-groups, subjects, and affected matrilineal relatives of all ages suffer at a far higher incidence from several dysautonomic-related conditions, including migraine and irritable bowel, as well as depression and hypothyroidism, while neuromuscular and cognitive disorders such as hypotonia and ADHD are common only in affected children. We conclude that mtDNA sequences predispose towards the development of protean disease manifestations in CVS patients ascertained through a disease-specific association, as well as among their matrilineal relatives, whether or not neuromuscular disease is present in the proband. Since CVS was absent in all but one matrilineal relative of our probands, CVS is apparently a rare clinical presentation in individuals carrying the predisposing mtDNA sequences. The four conditions reported most frequently among the matrilineal relatives of our cases, migraine, depression, irritable bowel, and hypothyroidism, are known to segregate together in families, and our findings suggest that a common predisposing genetic factor is likely present on the mtDNA.

Use of intravenous midazolam and clonidine in cyclical vomiting syndrome: a case report

We report a case of a teenage boy with cyclical vomiting syndrome (CVS) who was referred to the anesthesia-run postoperative pain service for symptom management. His symptoms were uncontrolled by oral pizotifen prophylaxis and acute therapy with intravenous (IV) hydration and ondansetron. A continuous low dose IV midazolam infusion was added to his treatment regimen (as is instituted for recalcitrant postoperative nausea and vomiting) with benefit, but not total symptom resolution. Recent literature review suggested links between migraine, CVS and adrenergic autonomic dysfunction. Consequently, IV clonidine was administered, in addition, with recovery. This combination was reinstituted successfully on subsequent admissions and emergency department presentations with shortened episode durations from 4-5 days to 16-48 h. It is uncertain if clonidine's sympatholytic effects were significantly beneficial or if associated sedation or natural resolution were contributors. Many agents have been used in CVS therapy but no trials have been done. Neither midazolam nor clonidine has been reported previously as used in the treatment of CVS. The apparent success of this combination raises possibilities both for future trials and research into the pathogenesis of CVS.

Abdominal migraine and cyclical vomiting

Vomiting and abdominal pain are symptoms that may arise from a number of different causes. Cyclical vomiting and abdominal migraine are terms that have been applied to a presentation characterized by its episodic pattern and intervals of complete health. The 2 share many clinical features, but it is important to distinguish them as they have different responses to therapies such as prophylactic antimigraine medications. Both are noted for the absence of pathognomonic clinical features but also for the large number of other conditions to be considered in their differential diagnoses. Definitive diagnosis is frequently delayed. It is important to carefully evaluate these patients as well-being between vomiting episodes does not guarantee the absence of organic disease. While there is a role for a basic set of diagnostic tests, there is evidence to suggest that a trial of empiric therapy with upper gastrointestinal and small-bowel radiological studies is cost-effective.

Cyclic vomiting syndrome: a brain-gut disorder

Despite the "black box" surrounding CVS, the authors' understanding of this clinical entity has advanced substantially in the last decade as a result of an international interdisciplinary clinical and research effort. Although CVS is now recognized as a unique clinical entity, patients still undergo innumerable hospitalizations and diagnostic tests. Although controlled therapeutic studies are lacking, reasonably effective empiric approaches have been developed by trial and error using anti-migraine, anti-emetic, and anti-epileptic regimens. The ongoing investigations of migraine mechanisms through NMR spectroscopy, mitochondrial DNA mutations and cellular energetics, corticotropin-releasing factor and gastric motility, and brainstem regulation of autonomic function may lead to breakthroughs in the understanding of and new therapies for CVS in the next decade.