1. Cyclical Vomiting Syndrome
Vomiting in Children
with emphasis on
Cyclical Vomiting Syndrome

2. The patient 10 year old girl
Admitted with acute onset vomiting for 1 day. Started as food, then became yellow/green
Abdominal pain
Weakness, lethargy
Precipitated by “ asthma attack” – used asthma inhaler
Previous similar episodes
No diarrhoea or constipation

3. Past medical history Recurrent episodes of vomiting – since infancy
Diagnosed with gastro-oesophageal reflux disease as infant
Episodes of vomiting more frequent, severe in past 2 years (occur every 1-3 months)
Almost always preceded/ precipitated by “asthma attack”. Sometimes even by laughing a lot
Frequently resulting in hospital admission – not for bronchospasm but for dehydration and intractable vomiting

4. Been extensively investigated (Cape Town) – barium meal, Xrays, gastroscopy, ?others => all negative
Apparently given medication in hospital each time admitted, but not on chronic medication other than steroid inhaler and bronchodilator
Parents have not been given a diagnosis as yet – very distressed
Past surgical history
Nil

5. Birth history Social Family History Term, nil of significance
Recently moved from Cape Town (in past month)
Grade 4 at school, doing well, apparently happy
8 year old brother, well
Stable, caring family environment
Family History
Father has asthma (mild)
No known history of migraine in family

6. Clinical Findings Well–grown child
Miserable, lethargic, and uncomfortable due to abdominal pain, but awake and cooperative
Haemodynamically stable but looked 5% dehydrated with sunken eyes
BP – 104/65mmHg
Low-grade fever – 37.5deg
Chest – clear
CVS – normal

7. Abdomen – scaphoid, soft but generally tender
Abdomen – scaphoid, soft but generally tender. No masses felt, bowel sounds heard. PR not done
CNS – Awake, but withdrawn. No meningism, no focal signs. No papilloedema.
FBC, urea and electrolytes normal except potassium borderline low (3.1 mmol/l)
Urine Dipstix – nil of note. No glycosuria
Ultrasound abdomen – normal
CT scan brain - normal

8. Management Admitted to ward Rehydrated with IV fluids
Allowed to take orally as desired
Panado, Cyclizine for vomiting

9. Progress Still vomiting in ward for about 2 days
Temperature settled in ward
Did not require nebuliser for bronchospasm
Very quiet, withdrawn and miserable for 2 days
By third day, was walking around looking better and vomiting had settled

10. Vomiting in Children
Vomiting is a symptom, presenting complaint in multitude of disorders
Range from gastrointestinal pathology to disease in distant organ (otitis media or intracranial lesion)
In children, especially infants, must distinguish from regurgitation – effortless expulsion of gastric contents
Integrated response to noxious stimuli, coordinated by central nervous system

11. Centres responsible for vomiting
Vomiting centre
Nucleus solitarius and series of nuclei in brainstem medulla
Stimulation results in
integrated motor responses involved in vomiting
associated vasomotor activity (pallor, flushing), salivation, bulbar responses
Afferent input arises from
posterior pharynx, GIT, brain

12. Chemoreceptor trigger zone
Stimulated by humoral stimuli such as opiates, cytotoxins, ketones, ammonia
Lies in area postrema – floor of 4th ventricle, outside blood-brain barrier
Processes most of afferent input for the vomiting centre
Receptors and neurotransmitters involved
Dopamine (D2), histamine (H1), serotonin (5-HT3), vasopressin, substance P

13. Diagnostic evaluation
Before finding cause of vomiting, in any child should first
Assess hydration status, attend to life-threatening complications
Ascertain whether
Bilious – suggests gastrointestinal obstruction
Blood is present – diagnosis and management different
If non-bilious and non-bloody, 2 important variables => temporal pattern and age of patient

14. Duration either
Acute – short-term episode, abrupt onset
Recurrent – at least 3 episodes over 3-month period => chronic - relatively mild episodes that occur frequently
=> cyclic – recurrent, intense episodes separated by asymptomatic periods

15. Acute Vomiting Neonate/ Infant Child/ adolescents With fever
Sepsis, meningitis, UTI
Tonsillitis, otitis media, gastroenteritis
If no signs sepsis
Pyloric stenosis/ outlet obstruction
Metabolic
Neurologic
Endocrine
Child/ adolescents
With fever (but otherwise well)
Gastroenteritis, esp if also have diarrhoea
With lethargy/ altered mental status
Neurologic
Metabolic
Endocrine
Drugs, toxins, alcohol

16. Investigations for acute vomiting
Thorough examination
“Septic workup” – blood cultures, urine, FBC, CRP, LP
Upper GI radiology – Barium swallow/ meal, AXR, ultrasound abdomen, endoscopy
Metabolic investigations – blood gas, ammonia, blood and urine organic acids

17. Management Depends on specific cause
While investigating/ treating underlying pathology – replace lost fluids, maintain hydration
If mild and child able to drink, can try oral rehydration. Intravenous may also be required
Pharmacologic agents not usually recommended
May mask signs of serious disease
Undesirable side-effects in children

18. Ongoing underlying pathology, therefore may be more worrying
Recurrent vomiting
Ongoing underlying pathology, therefore may be more worrying
Numerous causes
GIT
Infections – H. pylori, Giardia, oesophageal candidiasis
Hepatitis, pancreatitis, partial intestinal obstruction
Metabolic, neurologic, renal

19. Recurrent Vomiting Infants Older child/ Adolescent
GIT – feed intolerance
Renal
Metabolic – lethargy, poor feeding, failure to thrive, seizures, abnormal tone
Neurologic – raised pressure – meningitis, tumour, hydrocephalus
Older child/ Adolescent
GIT
Chronic sinusitis
Drug intoxication
Migraine
Bulimia
Pregnancy

20. Investigations Guided by history
Timing - early morning (or nocturnal) – reflux, peptic ulcer (empty stomach), intracranial mass lesion, pregnancy
Relation to eating - worse with food- suggests upper GIT abnormalities.
Description –
projectile suggests outlet obstruction (stomach, duodenum, more distal intestine)
faeculent – colonic obstruction, intestinal stasis, bowel ischaemia

21. Special investigations
Examination
Jaundice – liver/ gallbladder pathology
Neurologic examination important
Special investigations
Sinus Xrays
MRI/CT brain
Stool occult blood/ parasites
FBC, LFT, U&E, Amylase, ESR
Urinalysis and culture
Toxicology screen

22. If no diagnosis still, consider
Upper GI contrast study, ultrasound abdomen
Gastroscopy PLUS biopsy – high diagnostic yield, ease of performance, safe

23. Cyclic Vomiting Syndrome (CVS)
Paroxysmal, especially severe, recurrent vomiting disorder
Mysterious disorder, unknown aetiology, and pathophysiology
Substantial increase in interest and understanding of disease in past decade
Previously considered rare, may be 2nd only to GORD as cause of recurrent vomiting in children

24. Under-recognised Prevalence
No specific laboratory, radiographic or endoscopic markers for CVS
Typically misdiagnosed for years – viral GE, food poisoning, GORD, psychogenic vomiting => leads to inappropriate therapy
Surgery
Psychiatric hospitalisation
Very distressing to patients and families
Prevalence
Being diagnosed with increasing frequency, but actual prevalence remains unknown
0.04-2% among school-aged children
Overdiagnosed sometimes, and often underdiagnosed

25. Age and Sex distribution
Females>males
Similar to distribution in migraine sufferers
All races, nut more in Caucasians
Usually affects children of 4-7 yrs but some as young as 6 mths
Bimodal peaks: 4.8 and 35 yrs!

26. Course Often delays in diagnosis Median age of resolution 10 years
Average 2.7 years = ±20 episodes in children
Median age of resolution 10 years
In those whose vomiting resolves, about 1/3 develop migraine headaches around same time
Children ill <10% of time, but causes substantial medical and academic morbidity
Recurrent school absences
Recurrent admissions for IV fluids
Recurrent outpatient visits, hospital stays, missed work for parents

27. Features Hallmark – cyclic vomiting pattern => severe, recurring, discrete, stereotypical
high intensity, low frequency
More often require IV rehydration
Higher incidence of family members with migraine
Migraine symptoms – headaches, photophobia, phonophobia
Investigate causes outside GIT
Chronic
low intensity, high frequency, daily pattern
Investigate causes inside GIT

28. Cyclic Chronic Idiopathic If other cause – extraintestinal
Neurologic
Renal
Metabolic
Endocrine
Chronic
GIT disorders
Peptic oesophagitis

30. Clinical Features Short prodromal phase Episode itself Recovery phase
1.5 hours
Nonspecific premonitory signs such as pallor, lethargy, anorexia, nausea
Episode itself
Defined by median of 15 emeses, duration of 24 hours
Recovery phase
From last emesis to point of tolerating liquids and food, resume play – remarkably short 6 hours, often marked by sleep. “Turning off a switch”

31. Other Symptoms Other than vomiting 3 categories Systemic
Lethargy &/or pallor, withdrawal, flushing, fever, drooling
Extreme pallor could even mimic shock
Profound lethargy , inability to walk, talk, or interact can simulate semi-coma, confuse with meningitis, toxin ingestion

32. GI symptoms Neurologic symptoms
Anorexia, nausea, retching, abdominal pain (common), diarrhoea
fever and diarrhoea could confuse with viral GE – except for stereotypical recurrences. Also CVS patients look sicker, are often more dehydrated
Abdominal pain can mimic acute abdomen
Neurologic symptoms
Headache, photophobia, phonophobia, vertigo
<50% have classic migraine symptoms, but high occurrence of these symptoms supports link to migraines
Adolescents may assume foetal position to cope with hypersensitivity to light, sound, touch, upright positioning

33. Features (cont) Periodicity
Over 24 period – most common onset between 2am-4am and 6am-8am
?relationship to Corticotropin Releasing Factor
Over 1-3 month period – commonly every 4 weeks, but only half can predict next episode within 1 week on either side. Rest are sporadic
Seasonal – many worse in winter

34. Triggers Numerous events can trigger episode
Parents can often identify trigger
Most common
Psychologic – usually positive excitement rather than negative
Infectious – URTI’s, sinusitis, streptococcal pharyngitis
Also physical exhaustion, lack of sleep, dietary (chocolate, cheese, MSG), menstruation, motion sickness, asthma, allergies

35. Differential Diagnosis
Recurrent vomiting may be caused by neurologic, metabolic, endocrine, renal, gastrointestinal pathology
Cyclic vomiting - 12% have surgically-correctable lesion or metabolic disorder => therefore not Idiopathic CVS
NB: exclude malrotation, intermittent volvulus => if unrecognised could result in bowel resection
Genitourinary – acute hydronephrosis due to uretero-pelvic junction obstruction mimics CVS. Also nephrolithiasis
CNS – subtentorial neoplasms

36. Non-surgical GIT problems – GORD, food allergy to milk, wheat proteins
Chronic sinusitis
Metabolic – mitochondrial enzymopathies – infants, toddlers. Acute intermittent porphyria – adolescents – fasting and alcohol
Endocrine – Addison’s disease
Psychological – Munchausen-by-proxy, anxiety

37. Approach guided by need to exclude treatable underlying disorders
Diagnosis
Approach guided by need to exclude treatable underlying disorders
Imaging
First-line => Small bowel radiography, abdominal ultrasound/CT – exclude structural defects
Usually when child well – so can retain oral contrast
Second-line => sinus CT, CT or MRI head. Also gastroscopy if peptic disorders suspected

38. Laboratory Investigations
U&E, Glucose, lactate, ammonia, amino acids, urine organic acids
Assess complications (dehydration) and assist with diagnosis (metabolic disorders)
Screening for metabolic, endocrine disorders best done during episode as may be intermittently symptomatic
How much testing should be done?
High cost of complete testing vs potential morbidity of missed diagnosis
Single most useful test is small bowel series

39. Move on to 2nd line tests OR repeat 1st line tests for
Frequent, severe, prolonged episodes requiring repeated hospitalisations
Atypical features – severe headache
Refractory to medical management

40. Relationship to migraine
CVS thought to be migraine variant
Often family history of migraine
High rate of improvement on anti-migraine therapy
Can progress to migraine headaches once CVS episodes have ceased

41. Only empiric therapy at present 5 aspects
Treatment
Only empiric therapy at present
5 aspects
Avoidance of precipitating factors
Food and stressful events possible
Mostly unavoidable
Prophylactic agents
Anti-migraine – propranolol, amitryptiline
Anti-epileptic – phenobarbital, valproate
Prokinetic agents – erythromycin
Abortive agents

42. Supportive care Parenteral
Anti-migraine agents – Sumatriptan (5HT1B/1D agonist)
Anti-emetic agents – Ondansetron (5HT3 antagonist), even more effective with benzodiazepine (Lorazepam)
Supportive care
IV fluids – 10% dextrose-containing electrolyte solution – rehydration, terminate ketosis
Quiet, dark, non-stimulating environment
Sedatives –help to sleep, sleep may initiate recovery phase
Phenothiazine anti-emetics INEFFECTIVE in CVS
Opiates for pain may help but can worsen nausea

43. Family support
Crucial – unpredictable, disruptive, unexplained illness, often misdiagnosed, few definitive answers