Cyclic vomiting syndrome (CVS) is a condition with a specific pattern of vomiting with three main features: paroxysmal (sudden onset), stereotypical (similar episodes), and intervening periods of wellness. There is not one single test that confirms CVS; correct diagnosis is made by having a doctor take a careful history, performing a careful physical examination, and conducting tests to exclude other diseases.
What are the symptoms and signs of Cyclic vomiting syndrome (CVS)?
Patients present with vomiting episodes that tend to recur in a cyclical pattern, such as every 2 weeks, or every 2 months. The vomiting is paroxysmal, or with sudden onset. Most patients with CVS feel well, until they get a sudden attack of nausea, which usually progresses to vomiting a little later. The nausea and vomiting often start in the evening, and many times can even wake the patient from sleep.
Second, the vomiting episodes are stereotypical. Each vomiting “attack” resembles similar episodes they have had previously. Very often, the attacks last between 8 and 24 hours. However, for some patients, attacks can be as brief as 1-2 hours, and for others they can last several days. Episodes often begin with nausea, and progress to vomiting, with some people vomiting several times an hour. During the vomiting episodes, patients often like to be left alone or be in a quiet place. Other symptoms can also occur during the episode, including severe stomach pain, diarrhea, and headache. Patients can become disoriented, irritable and turn pale and clammy during an attack. Some patients vomit to the point of dry heaves or become dehydrated. The episodes often resolve by themselves without any obvious intervention or explanation.
How common is Cyclic vomiting syndrome (CVS)?
About 1 in 33,000 children are thought to have CVS. It can occur in adulthood as well, but is more common during childhood.
What causes Cyclic vomiting syndrome (CVS)?
The definite cause of CVS is unknown. A number of medical studies suggest that in most patients, CVS is related to migraine. The sudden onset of attacks with spontaneous resolution is also seen in patients with migraine headaches. Most (but not all) children with CVS have a family history of migraine. In addition, many of the treatments used to treat migraine headaches are also effective in treating CVS.
What is the treatment for CVS?
Treatment for Cyclic vomiting syndrome (CVS) is divided into two major types: abortive therapy and prophylactic therapy. Abortive therapy means giving treatments to stop the episode once it starts, and only giving that treatment during the episode. In contrast, prophylactic therapy means giving a medication every day, whether the child is well or sick, in order to prevent episodes from coming on.
Once a CVS episode starts, it can be very hard to stop. For many patients, the best treatment is supportive, and can, in severe cases, include intravenous fluids and a quiet room in a hospital. Antinausea medicines, including ondansetron (Zofran), promethazine (Phenergan), and chlorpromazine (Thorazine) are sometimes used to reduce the feelings of nausea. Because patients may be anxious and just feel lousy during an attack, they may benefit from an antianxiety medication such as lorazepam (Ativan). Other patients may benefit from antimigraine treatments like sumatriptan (Imitrex). After enough time passes (usually hours to days), most patients come out of the episode.
Prophylactic treatments are medications given on a daily basis to try to prevent episodes from coming on. Studies suggest that in patients with frequent episodes (every 1-2 months), prophylactic treatment can lessen the frequency and severity of episodes. Therefore, in patients having frequent episodes (i.e. every 1-2 months,) prophylactic treatment should be considered. However, if episodes are infrequent (i.e. once a year), prophylactic therapy is probably unnecessary. Prophylactic medications include cyproheptadine, propanolol, and amitriptyline. In some patients with resistant disease, anticonvulsants (i.e. medicines usually used to treat seizures) are often used. These medications include topiramate, valproate, and levetiracetam. While all these prophylactic medicines are generally safe, each has a different side effect profile, and so the benefits and risks of prophylactic therapy need to be reviewed with your physician .
What tests are used in children to diagnose CVS?
In general, the history will strongly suggest CVS. However, in many cases, a physician may need to perform further tests to exclude other conditions. These tests may include: an upper GI series (x-ray with contrast to exclude malrotation), an abdominal ultrasound (ultrasound of kidneys and gallbladder to rule out pathology), and a CT scan or MRI of the head. In addition, during a CVS episode, blood tests and urine tests may need to be obtained to evaluate for other causes of the episode (including infection, inflammation of the pancreas, and metabolic enzyme problems). In some patients, endoscopy (examination of the esophagus and stomach with a scope/video camera that passes by the mouth and goes into the stomach) may be needed.