Cyclic vomiting syndrome plus

Whole exome/genome sequencing in cyclic vomiting syndrome reveals multiple candidate genes, suggesting a model of elevated intracellular cations and mitochondrial dysfunction

Objective

To utilize whole exome or genome sequencing and the scientific literature for identifying candidate genes for cyclic vomiting syndrome (CVS), an idiopathic migraine variant with paroxysmal nausea and vomiting.

Methods

A retrospective chart review of 80 unrelated participants, ascertained by a quaternary care CVS specialist, was conducted. Genes associated with paroxysmal symptoms were identified querying the literature for genes associated with dominant cases of intermittent vomiting or both discomfort and disability; among which the raw genetic sequence was reviewed. "Qualifying" variants were defined as coding, rare, and conserved. Additionally, "Key Qualifying" variants were Pathogenic/Likely Pathogenic, or "Clinical" based upon the presence of a corresponding diagnosis. Candidate association to CVS was based on a point system.

Results

Thirty-five paroxysmal genes were identified per the literature review. Among these, 12 genes were scored as "Highly likely" (SCN4A, CACNA1A, CACNA1S, RYR2, TRAP1, MEFV) or "Likely" (SCN9A, TNFRSF1A, POLG, SCN10A, POGZ, TRPA1) CVS related. Nine additional genes (OTC, ATP1A3, ATP1A2, GFAP, SLC2A1, TUBB3, PPM1D, CHAMP1, HMBS) had sufficient evidence in the literature but not from our study participants. Candidate status for mitochondrial DNA was confirmed by the literature and our study data. Among the above-listed 22 CVS candidate genes, a Key Qualifying variant was identified in 31/80 (34%), and any Qualifying variant was present in 61/80 (76%) of participants. These findings were highly statistically significant (p < 0.0001, p = 0.004, respectively) compared to an alternative hypothesis/control group regarding brain neurotransmitter receptor genes. Additional, post-analyses, less-intensive review of all genes (exome) outside our paroxysmal genes identified 13 additional genes as "Possibly" CVS related.

Conclusion

All 22 CVS candidate genes are associated with either cation transport or energy metabolism (14 directly, 8 indirectly). Our findings suggest a cellular model in which aberrant ion gradients lead to mitochondrial dysfunction, or vice versa, in a pathogenic vicious cycle of cellular hyperexcitability. Among the non-paroxysmal genes identified, 5 are known causes of peripheral neuropathy. Our model is consistent with multiple current hypotheses of CVS.

Association of Mitochondrial DNA Polymorphisms With Pediatric-Onset Cyclic Vomiting Syndrome

BACKGROUND

Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder characterized by recurrent stereotypic episodes of vomiting. The pathophysiology of CVS remains obscure. Previous studies have supported the hypotheses of mitochondrial dysfunction. However, data on association studies between mitochondrial DNA (mtDNA) polymorphisms and pediatric-onset CVS are limited and inconsistent. The aims of this study were to describe clinical characteristics, evaluate association of mtDNA polymorphisms 16519T and 3010A with pediatric-onset CVS and identify new mtDNA candidate variants.

METHODS

This study involved Thai patients diagnosed with CVS according to the Rome III or IV criteria before the age of 15 years. Patients' demographic data, clinical characteristics, previous investigations and treatment outcomes were obtained. Blood samples were collected for next-generation (whole exome) sequencing, followed by analysis of chromosome M (mitochondrial. Variants were filtered according to clinical significance using ClinVar and MITOMAP. mtDNA polymorphisms in 148 normal Thai individuals were used as controls.

RESULTS

Forty-eight children were enrolled in the clinical study, and 30 participated in the genetic analysis. The median age at onset and median age at diagnosis was 3.0 (1.5-5.6) and 6.3 (3.0-8.6) years, respectively. Maternal history of migraine was positive in 16.7%. About 45.7% (21 of 46) of the patients achieved complete clinical remission, with the mean symptom duration of 5.9 ± 3.3 years. The prevalence of mtDNA variants 16519T and 3010A among the patient group and Thai general population (control) were as follows: 40.0% (12/30) vs. 27.7% (P = 0.18) and 6.7% (2/30) vs. 0.7% (P = 0.07), respectively. Five known pathogenic variants were identified in 6 patients, including mtDNA 8528C in one patient who also had infantile hypertrophic cardiomyopathy. Six likely pathogenic variants were found but without statistical significance. We identified 11 variants with significant prevalence in the patient group. Though, these variants were classified as variants of unknown significance (VUS), several of them were located in mt functional regions and therefore they deserve further investigations as new candidates for association with pediatric CVS.

CONCLUSION

There were no associations of mtDNA polymorphisms 16519T and 3010A with CVS in our pediatric cohort. Five pathogenic variants and 11 VUS were found associated with pediatric-onset 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.

Neurological Etiologies and Pathophysiology of Cyclic Vomiting Syndrome

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

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.

Quantitative pedigree analysis and mitochondrial DNA sequence variants in adults with cyclic vomiting syndrome

Background

Children with cyclic vomiting syndrome (CVS) have a high degree of maternal inheritance of functional gastrointestinal and neurological disorders. CVS in children is also associated with an increased prevalence of mitochondrial DNA single-nucleotide polymorphisms (mtDNA SNPs) 16519 T and 3010A. Preliminary data suggests that age of onset of symptoms (pediatric vs. adult) may be a determinant of the presence of such mtDNA SNP’s. We sought to examine the degree of maternal inheritance pattern of functional disorders and the prevalence of mtDNA SNP’s16519T and 3010A in adults with CVS and correlate this with age of onset of disease.

Methods

A Quantitative Pedigree Analysis (QPA) was performed in 195 of a total of 216 patients and all were genotyped using Restriction Fragment Length Polymorphism (RFLP) or sequencing.

Results

Adults with CVS had a higher degree of probable maternal inheritance (PMI) of functional disorders than controls (12% vs. 1%, p < 0.001). However, the prevalence of mitochondrial SNP’s 16519 T, 3010A and the AT genotype were similar in Haplogroup H CVS patients compared to historical controls. There was no correlation between age of onset of disease and prevalence of these mtDNA SNP’s.

Conclusions

A subset of adults with CVS has a significantly higher degree of maternal inheritance pattern of functional disorders than controls. There was no association with mtDNA SNP’s 16519 T and 3010A as seen in children and future studies sequencing the entire mitochondrial and nuclear genome to identify potential causes for this maternal inheritance pattern in adults are warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-230X-14-181) contains supplementary material, which is available to authorized users.

The use of SmartPill for gastric monitoring

Testing to define delayed gastric emptying is required to diagnose gastroparesis; rapid emptying is found in other patients. Commonly performed methods of gastric emptying testing include scintigraphy and breath testing. The SmartPill wireless motility capsule (WMC) system is US FDA-approved for evaluating suspected delayed emptying in gastroparesis and functional dyspepsia. The device measures transit in the stomach, small intestine, and colon by detecting characteristic pH transitions; and quantifies pressure waves in each gut region. WMC gastric emptying times correlate with scintigraphic measures. Incremental benefits of WMC testing in patients with suspected gastroparesis include delineation of pressure abnormalities and small intestinal and colonic transit delays. Acceptance of trial data confirming usefulness of WMC testing in suspected gastric motor disorders has been hampered by small sample sizes and design limitations. Ongoing multicenter studies will validate the utility of WMC methods in patients with suspected gastroparesis and other upper gastrointestinal motor disorders.

Mitochondrial disorder caused Charles Darwin's cyclic vomiting syndrome

BACKGROUND

Charles Darwin (CD), "father of modern biology," suffered from multisystem illness from early adulthood. The most disabling manifestation was cyclic vomiting syndrome (CVS). This study aims at finding the possible cause of CVS in CD.

METHODS

A literature search using the PubMed database was carried out, and CD's complaints, as reported in his personal writings and those of his relatives, friends, colleagues, biographers, were compared with various manifestations of mitochondrial disorders (MIDs), known to cause CVS, described in the literature.

RESULTS

Organ tissues involved in CD's disease were brain, nerves, muscles, vestibular apparatus, heart, gut, and skin. Cerebral manifestations included episodic headache, visual disturbance, episodic memory loss, periodic paralysis, hysterical crying, panic attacks, and episodes of depression. Manifestations of polyneuropathy included numbness, paresthesias, increased sweating, temperature sensitivity, and arterial hypotension. Muscular manifestations included periods of exhaustion, easy fatigability, myalgia, and muscle twitching. Cardiac manifestations included episodes of palpitations and chest pain. Gastrointestinal manifestations were CVS, dental problems, abnormal seasickness, eructation, belching, and flatulence. Dermatological manifestations included painful lips, dermatitis, eczema, and facial edema. Treatments with beneficial effects to his complaints were rest, relaxation, heat, and hydrotherapy.

CONCLUSION

CVS in CD was most likely due to a multisystem, nonsyndromic MID. This diagnosis is based upon the multisystem nature of his disease, the fact that CVS is most frequently the manifestation of a MID, the family history, the variable phenotypic expression between affected family members, the fact that symptoms were triggered by stress, and that only few symptoms could not be explained by a MID.

The combination of thermal dysregulation and agenesis of corpus callosum: Shapiro's or/and reverse Shapiro's syndrome

Shapiro syndrome is an extremely rare condition consisting the clinical triad of recurrent hypothermia, hyperhydrosis and agenesis of the corpus callosum. On the other hand, reverse Shapiro's sydrome is characterized periodic hyperthermia and agenesis of the corpus callosum. Here, we describe a 3.5-year-old girl with complete agenesis of corpus callosum presenting with recurrent fever and vomiting. She also had hypothermia attacks with accompanying diaphoresis. To the best of our knowledge, there is no described case with episodes of hyperthermia, hypothermia, and vomiting associated with agenesis of the corpus callosum. Recurrent vomiting may be a newly defined symptom associated with these syndromes.

A novel syndrome caused by the E410K amino acid substitution in the neuronal β-tubulin isotype 3

Missense mutations in TUBB3, the gene that encodes the neuronal-specific protein β-tubulin isotype 3, can cause isolated or syndromic congenital fibrosis of the extraocular muscles, a form of complex congenital strabismus characterized by cranial nerve misguidance. One of the eight TUBB3 mutations reported to cause congenital fibrosis of the extraocular muscles, c.1228G>A results in a TUBB3 E410K amino acid substitution that directly alters a kinesin motor protein binding site. We report the detailed phenotypes of eight unrelated individuals who harbour this de novo mutation, and thus define the 'TUBB3 E410K syndrome'. Individuals harbouring this mutation were previously reported to have congenital fibrosis of the extraocular muscles, facial weakness, developmental delay and possible peripheral neuropathy. We now confirm by electrophysiology that a progressive sensorimotor polyneuropathy does indeed segregate with the mutation, and expand the TUBB3 E410K phenotype to include Kallmann syndrome (hypogonadotropic hypogonadism and anosmia), stereotyped midface hypoplasia, intellectual disabilities and, in some cases, vocal cord paralysis, tracheomalacia and cyclic vomiting. Neuroimaging reveals a thin corpus callosum and anterior commissure, and hypoplastic to absent olfactory sulci, olfactory bulbs and oculomotor and facial nerves, which support underlying abnormalities in axon guidance and maintenance. Thus, the E410K substitution defines a new genetic aetiology for Moebius syndrome, Kallmann syndrome and cyclic vomiting. Moreover, the c.1228G>A mutation was absent in DNA from ∼600 individuals who had either Kallmann syndrome or isolated or syndromic ocular and/or facial dysmotility disorders, but who did not have the combined features of the TUBB3 E410K syndrome, highlighting the specificity of this phenotype-genotype correlation. The definition of the TUBB3 E410K syndrome will allow clinicians to identify affected individuals and predict the mutation based on clinical features alone.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Cessation of cyclic vomiting in a 7-year-old girl after upper cervical chiropractic care: a case report

OBJECTIVE

The purpose of this case report is to describe chiropractic management of a child with cyclic vomiting syndrome.

CLINICAL FEATURES

A 7-year-old girl had a history of cyclic vomiting episodes for the past 4 1/2 years. She also had a 2-month history of headaches and stomachache.

INTERVENTION AND OUTCOME

The patient received low-force chiropractic spinal manipulation to her upper cervical spine. There was improvement in her symptoms within an hour after the chiropractic manipulation. Her symptoms only returned after direct trauma to her neck. The recurring symptoms again disappeared immediately after treatment.

CONCLUSION

This case study suggests that there may be a role for the use of chiropractic spinal manipulative therapy for treating cyclic vomiting syndrome. Controlled studies are necessary to aid our understanding of this finding.

[Childhood periodic syndromes]

This review focuses on the so-called "periodic syndromes of childhood that are precursors to migraine", as included in the Second Edition of the International Classification of Headache Disorders. Three periodic syndromes of childhood are included in the Second Edition of the International Classification of Headache Disorders: abdominal migraine, cyclic vomiting syndrome and benign paroxysmal vertigo, and a fourth, benign paroxysmal torticollis is presented in the Appendix. The key clinical features of this group of disorders are the episodic pattern and intervals of complete health. Episodes of benign paroxysmal torticollis begin between 2 and 8 months of age. Attacks are characterized by an abnormal inclination and/or rotation of the head to one side, due to cervical dystonia. They usually resolve by 5 years. Benign paroxysmal vertigo presents as sudden attacks of vertigo, accompanied by inability to stand without support, and lasting seconds to minutes. Age at onset is between 2 and 4 years, and the symptoms disappear by the age of 5. Cyclic vomiting syndrome is characterized in young infants and children by repeated stereotyped episodes of pernicious vomiting, at times to the point of dehydration, and impacting quality of life. Mean age of onset is 5 years. Abdominal migraine remains a controversial issue and presents in childhood with repeated stereotyped episodes of unexplained abdominal pain, nausea and vomiting occurring in the absence of headache. Mean age of onset is 7 years. Both cyclic vomiting syndrome and abdominal migraine 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. Diagnostic criteria, such as those of the Second Edition of the International Classification of Headache Disorders and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, have made diagnostic approach and management easier. Their diagnosis is entertained after exhaustive evaluations have proved unrevealing. The recommended diagnostic approach uses a strategy of targeted testing, which may include gastrointestinal and metabolic evaluations. Therapeutic recommendations include reassurance, both of the child and parents, lifestyle changes, prophylactic therapy (e.g., cyproheptadine in children 5 years or younger and amitriptyline for those older than 5 years), and acute therapy (e.g., triptans, as abortive therapy, and 10% glucose and ondansetron for those requiring intravenous hydration).

Treatment of cyclic vomiting syndrome with co-enzyme Q10 and amitriptyline, a retrospective study

Background

Cyclic vomiting syndrome (CVS), which is defined by recurrent stereotypical episodes of nausea and vomiting, is a relatively-common disabling condition that is associated with migraine headache and mitochondrial dysfunction. Co-enzyme Q10 (Co-Q) is a nutritional supplement that has demonstrated efficacy in pediatric and adult migraine. It is increasingly used in CVS despite the complete lack of studies to demonstrate its value in treatment

Methods

Using an Internet-based survey filled out by subjects with CVS or their parents, the efficacy, tolerability and subject satisfaction in CVS prophylaxis were queried. Subjects taking Co-Q (22 subjects) were compared against those taking amitriptyline (162 subjects), which is the general standard-of-care.

Results

Subjects/parents reported similar levels of efficacy for a variety of episode parameters (frequency, duration, number of emesis, nausea severity). There was a 50% reduction in at least one of those four parameters in 72% of subjects treated with amitriptyline and 68% of subjects treated Co-Q. However, while no side effects were reported on Co-Q, 50% of subjects on amitriptyline reported side effects (P = 5 × 10^-7), resulting in 21% discontinuing treatment (P = 0.007). Subjects/parents considered the benefits to outweigh the risks of treatment in 47% of cases on amitriptyline and 77% of cases on Co-Q (P = 0.008).

Conclusion

Our data suggest that the natural food supplement Co-Q is potentially efficacious and tolerable in the treatment of CVS, and should be considered as an option in CVS prophylaxis. Our data would likely be helpful in the design of a double-blind clinical trial.

Childhood periodic syndromes

This review focuses on so-called "periodic syndromes of childhood that are precursors to migraine," as included in the second edition of the International Classification of Headache Disorders. Presentation is characterized by an episodic pattern and intervals of complete health. Benign paroxysmal torticollis is characterized by recurrent episodes of head tilt, secondary to cervical dystonia, with onset between ages 2-8 months. Benign paroxysmal vertigo presents as sudden attacks of vertigo lasting seconds to minutes, accompanied by an inability to stand without support, between ages 2-4 years. Cyclic vomiting syndrome is distinguished by its unique intensity of vomiting, affecting quality of life, whereas abdominal migraine presents as episodic abdominal pain occurring in the absence of headache. Their mean ages of onset are 5 and 7 years, respectively. Diagnostic criteria and appropriate evaluation represent the key issues. Therapeutic recommendations include reassurance, lifestyle changes, and prophylactic as well as acute antimigraine therapy.

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.

Dysautonomia, a heuristic approach to a revised model for etiology of disease

Dysautonomia refers to a disease where the autonomic nervous system is dysfunctional. This may be a central control mechanism, as in genetically determined familial dysautonomia (Riley-Day Syndrome), or peripherally in the distribution of the sympathetic and parasympathetic systems. There are multiple reports of a number of different diseases associated with dysautonomia. The etiology of this association has never been explained. There are also multiple publications on dysautonomia associated with specific non-caloric nutritional deficiencies. Beriberi is the prototype of autonomic dysfunction. It is the best known nutritional deficiency disease caused by an imbalance between ingested calories and the vitamins required for their oxidation, particularly thiamin. Long thought to be abolished in modern medical thinking, there are occasional isolated reports of the full-blown disease in developed Western cultures. Apart from genetically and epigenetically determined disease, evidence is presented that marginal high calorie malnutrition, particularly with reference to simple carbohydrates, is responsible for widespread dysautonomia. The brain and heart are the organs that have a fast rate of oxidative metabolism and are affected early by any mechanism that reduces oxidative efficiency. It is hypothesized that this results in a chaotic state of the hypothalamic/autonomic/endocrine axis. Due to the lack of adequate automatic controls, this may be responsible in some cases for breakdown of organ systems through long-standing energy deficiency, thus leading eventually to organic disease.

Two common mitochondrial DNA polymorphisms are highly associated with migraine headache and cyclic vomiting syndrome

Mitochondrial dysfunction is a hypothesized component in the multifactorial pathogenesis of migraine without aura (MoA, 'common migraine') and the related condition of cyclic vomiting syndrome (CVS). In this study, the entire mitochondrial genome was sequenced in 20 haplogroup-H CVS patients, a subject group studied because of greater genotypic and phenotypic homogeneity. Sequences were compared against haplogroup-H controls. Polymorphisms of interest were tested in 10 additional CVS subjects and in 112 haplogroup-H adults with MoA. The 16519C-->T polymorphism was found to be highly disease associated: 21/30 CVS subjects [70%, odds ratio (OR) 6.2] and 58/112 migraineurs (52%, OR 3.6) vs. 63/231 controls (27%). A second polymorphism, 3010G-->A, was found to be highly disease associated in those subjects with 16519T: 6/21 CVS subjects (29%, OR 17) and 15/58 migraineurs (26%, OR 15) vs. 1/63 controls (1.6%). Our data suggest that these polymorphisms constitute a substantial proportion of the genetic factor in migraine pathogenesis, and strengthen the hypothesis that there is a component of mitochondrial dysfunction in migraine.

The incidence of cyclic vomiting syndrome in children: population-based study

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

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.

Neuroimaging findings in children with rare or novel de novo chromosomal anomalies

BACKGROUND

De novo constitutional chromosomal anomalies provide important insights into the genetic loci responsible for congenital neurological disorders. However, most phenotypic descriptions of patients with rare chromosomal abnormalities are published as individual case reports or small group studies, making genotype-phenotype correlations unclear. Moreover, many clinical genetic reports do not include neuroimaging.

METHODS

We conducted a retrospective case series study of all children who had genetic testing done at Children's Memorial Hospital in Chicago, Illinois between 1985 and 2006. The case series was selected from a database containing all chromosomal testing results, clinical data, and neuroimaging. Clinical examination results were assigned by board certified geneticists and/or neurologists and neuroimages were reviewed by both a neurologist or neuroradiologist and a blinded neurologist.

RESULTS

Of the 28,108 children in the series, we identified 34 children with novel or apparently novel de novo chromosomal abnormalities. Several of the cases represent potentially new genetic loci for neurological malformations and novel syndromic conditions.

CONCLUSIONS

This study demonstrates the utility of large clinical databases in assessing genotype-phenotype correlations and mapping loci for congenital neurological disorders. We describe a case-series strategy to analyze existing databases to reveal new genotype-phenotype correlations.

Combined cyclic vomiting and Kearns-Sayre syndromes

The third case of cyclic vomiting syndrome with a large mitochondrial deoxyribonucleic acid rearrangement is described. Multiple neuromuscular anomalies are present that meet the diagnostic criteria for Kearns-Sayre syndrome, as well as severe symmetrical growth retardation. A 3-kilobase mitochondrial deoxyribonucleic acid deletion (nucleotides 10970-14118) was found at 30-40% heteroplasmy in the blood of the child, but not the mother. Although mitochondrial dysfunction and disease-associated mitochondrial deoxyribonucleic acid sequence variants are believed to be present in most cyclic vomiting syndrome cases, these variants are rarely identifiable on "standard" mitochondrial deoxyribonucleic acid testing. However, finding a rearrangement has clinical implications, and standard testing is recommended in those cyclic vomiting syndrome cases with neuromuscular disease and/or growth retardation, whether maternal inheritance is present or not.