Cyclical vomiting syndrome
A syndrome that may be associated with migraine
Children have a lower threshold for vomiting than adults. It is not unusual for children to vomit in the course of common illnesses such as upper respiratory tract infection, ear infection, gastroenteritis and urine infection. Children also vomit after minor head injuries as well as in the course of serious illnesses such as meningitis. The vomiting centre in the brainstem can therefore be triggered by many stimuli, from local brain disorder or by chemicals produced in other parts of the body. Pain, smell and emotional upset may also cause the child to vomit.
Vomiting is also common among children with migraine; 85-90 per cent experience nausea and 55-60 per cent experience actual vomiting during attacks of migraine. Vomiting may therefore dominate the clinical picture of migraine attacks, and headache may be of secondary importance to the child. In some children, especially those under the age of six years, vomiting may be the main symptom of migraine presenting as recurrent episodes of vomiting lasting for several hours or days. The child may have all the features of migraine attacks except for the headache. This condition is known as ‘cyclical vomiting syndrome’ or CVS. Between attacks the child is well and returns to normal health.
Clinical features of cyclical vomiting syndrome (CVS)
Around two per cent of children suffer episodes of vomiting at least five times per year which is one criterion for the diagnosis of CVS. Younger children are more commonly affected than older ones, and boys and girls are equally affected. As they grow older some children stop having CVS, perhaps by the teenage years, while others continue through adult life. About half of the children with CVS grow up to suffer typical migraine attacks with headache as the major symptom.
The attacks of CVS often occur with predictable regularity every two to eight weeks. Attacks last for an average of 24 hours, but longer attacks are not uncommon. During the attack of CVS the child looks pale and unwell, loses appetite, feels nauseated and vomits several times per hour. The child will be lethargic and may get dehydrated. Occasionally the child may complain of abdominal pain or headache and may report light, noise or smell intolerance. The attacks resolve spontaneously after a variable duration of up to three days after which the child wants to lie down and sleep. Between attacks the child returns to normal.
Criteria for cyclical vomiting
The International Headache Society has accepted CVS as a migraine syndrome of childhood and includes it in the 2004 International Classification of Headache Disorders. The criteria for the diagnosis of CVS include the following:
- A. At least five attacks overall fulfilling criteria B and C;
- B. Episodic attacks, stereotypical in the individual patient, of intense nausea and vomiting, lasting one hour to five days;
- C. Vomiting during attacks occurs at least four times per hour for at least one hour;
- D. Symptom-free between attacks;
- E. Not attributed to another disorder.
History and physical examination do not show signs of gastrointestinal disease.
Management of cyclical vomiting syndrome (CVS)
A complete diagnostic assessment including history, physical examination, biochemical blood and urine tests and on occasions an X-ray or an ultrasound scan may also be needed to exclude other conditions that may present with episodes of vomiting.
Once the diagnosis of CVS is confidently made, a comprehensive treatment plan can be designed on the same lines as those of the migraine model comprising management of acute attacks and also measures for prevention.
The objectives for treatment of acute attacks are to provide medications that may prevent or stop vomiting and to give as much fluids as can be tolerated in order to prevent dehydration.
Several anti-emetic drugs can be given, with caution, orally as soon as possible after the onset of attacks. These may include ondansetron, promethazine, metoclopromide or prochlorperazine.
Fluids may be given orally at home, if possible, or by intravenous infusion in hospital. Specific anti-migraine drugs such as nasal imigran (sumatriptan) have been used on occasions with success and may abort the attack, but this treatment is not licensed for children under the age of 12 years.
The other aspect of treatment is prevention which can offer a better chance of controlling the disease and avoiding frequent hospital admission. Anti-migraine prophylactic medications such as pizotifen, amitriptyline and propranolol can be considered though none is sure to be successful in all cases. The antibiotic erythromycin can also prevent episodes of vomiting and may have a role in the prevention of CVS. Other drugs have been reported, but with limited supporting evidence of their benefits.
Written by Dr Ishaq Abu-Arafeh, MBBS, MD, MRCP, FRCPCH, who is a Consultant Paediatrician with an interest in Paediatric Neurology at Stirling Royal Infirmary NHS Trust, Stirling and has run the headache clinic for children at the Royal Hospital for Sick Children, Glasgow since 1996.