First described in 1882, cyclic
syndrome (CVS) is a rare idiopathic disorder characterized by recurring
periods of vomiting in an otherwise normal child. The word, idiopathic,
means that the origin of the disorder is unknown. The syndrome is
sometimes called abdominal migraine because it may be caused by some of
the same mechanisms in the central nervous system that cause migraine
Children with cyclic vomiting syndrome have bouts of severe
nausea and vomiting
that may last for hours or days. In some cases the vomiting is so severe
that the child is unable to go to school for several days. The episodes
alternate with periods of normal digestive functioning.
The bouts of vomiting that characterize CVS usually begin at the same time
of day as previous episodes, last about the same length of time, and have
the same symptoms. The most common pattern is severe
and vomiting that begins late at night or early in the morning. The child
may vomit as often as six to 12 times an hour over a period of one to five
days, although cases have been reported in which the episode lasts for ten
days. The vomited material may contain blood or bile as well as mucus or
In addition to the vomiting, the child may have a
fever, dizziness, pain
in the abdomen, heavy drooling, and
. Some children also become unusually sensitive to light, while others may
be unable to walk or talk.
Children between the ages of three and seven years are most susceptible to
CVS, although it can appear at any time from infancy to adulthood. The
average age of patients at onset is 5.2 years, but CVS has been diagnosed
in patients as old as 73.
The frequency of cyclic vomiting syndrome in the general population is not
known for certain as of the early 2000s, but it is thought that the
disorder is probably underdiagnosed because other diseases and disorders
can also cause periods of acute nausea and vomiting. Some researchers
think that as many as one child in 50 may have CVS.
CVS appears to affect all races and ethnic groups equally. The
female-to-male ratio has been reported as 11 to nine.
Causes and symptoms
The cause of CVS is as of 2004 a mystery. Similarities to migraine suggest
a common cause, but no firm evidence has been found. It is known, however,
that 82 percent of patients with CVS have a
history of migraine compared to 14 percent of control subjects. Patients
can usually identify some factor that precedes an attack. Common triggers
of CVS episodes include the following:
In the summer of 2003, two teams of researchers in Italy and the United
States reported that some cases of CVS appear to be caused by a DNA
mutation that affects the proper functioning of the mitochondria (energy
generators) in human cells and that this mutation is inherited from the
mother. Further research is needed, however, in order to determine whether
other genetic factors are involved in CVS.
Vomiting associated with CVS can be protracted and lead to such
; erosion of tooth enamel leading to
; unbalanced blood electrolyte levels; and tearing, burning, or bleeding
of the esophagus (swallowing tube). Between attacks, however, the child
has no sign of any illness.
CVS has four distinct stages or phases:
The vomiting and other symptoms associated with CVS are so severe that
parents will usually call the doctor during the first episode, before a
pattern has been identified. It may take several episodes of the disorder
before the parents or the doctor notice a pattern.
The most important and difficult aspect of diagnosing CVS is to make sure
there is not an acute and life-threatening event in progress. So many
different diseases can cause vomiting—from bowel obstruction to
epilepsy—that an accurate and timely diagnosis is critical. Because
there is no way to prove the diagnosis of CVS, the physician must instead
disprove every other diagnosis. This process, which is known as a
diagnosis of exclusion, can be tedious, expensive, exhausting, and involve
almost every system in the body. The first episode of cyclic vomiting
syndrome may be diagnosed as stomach flu when nothing more serious turns
up. Only after several episodes and several fruitless searches for a cause
will a physician normally consider the diagnosis of CVS.
A careful history-taking is critical to making the correct diagnosis of
CVS. A family history of migraine, particularly on the mother's
side of the family, should alert the doctor to the possibility that the
patient has CVS. The doctor may also order blood tests for metabolic
screening or imaging studies of the kidneys, gall bladder, small bowel, or
sinuses in order to rule out endocrine disorders, gastrointestinal
disorders, kidney disease, and chronic
In some cases, the doctor may refer the patient to a psychiatrist for
evaluation in order to rule out depression, anxiety disorders, or an
There is no permanent cure for cyclic vomiting syndrome as of the early
2000s. Doctors as of 2004 recommend a combination of several strategies
for managing the disorder:
Another medication that has been reported to be successful in treating
children with CVS is dexmedetomidine (Precedex), which was originally
developed to sedate patients on respirators in intensive care settings.
The researchers found that dexmedetomidine relieved the anxiety as well as
the nausea associated with CVS.
Constitutional homeopathic medicine can work well in treating CVS because
it addresses the person's overall health, not just the treatment of
Stress management techniques may be helpful for older children or
teenagers in preventing episodes of CVS triggered by emotional or
psychological stress. These techniques may include the relaxation response
developed by Herbert Benson, meditation, and biofeedback.
Weekly outpatient acupuncture treatments are also helpful to some children
Avoiding dehydration is the primary nutritional concern during episodes of
cyclic vomiting syndrome. In most cases the child will bring up water that
is offered during the acute phase of an attack even though he or she may
be very thirsty. About 50 percent of children require an intravenous
infusion of glucose and water to prevent dehydration.
Some children have a normal appetite for food soon after the vomiting
stops, while others may take several days to return to a full diet.
Parents should offer the child clear liquids first to prevent dehydration
and gradually reintroduce solid foods as the child's appetite
The average duration of cyclic vomiting syndrome is 2.5 to 5.5 years. Some
children, however, continue to have episodes of the disorder into
adulthood. About 60 percent of children diagnosed with CVS eventually
develop migraine headaches in
or early adulthood. If the more severe complications of prolonged
vomiting can be successfully prevented or managed, however, most patients
can lead normal lives between acute attacks.
Some episodes of vomiting may be prevented by avoiding specific triggers
or by taking prophylactic medications. As the cause of the disorder is as
of 2004 not yet fully understood, however, there is no way to prevent CVS
as a whole.
Cyclic vomiting syndrome can be a heavy emotional and financial burden on
the families of affected children. Episodes of CVS are often upsetting or
downright frightening to other family members, in addition to the fact
that they often spoil family outings or vacations when they are triggered
by excitement or motion sickness. Moreover, CVS can interfere with a
child's schooling; most children diagnosed with the disorder miss
an average of 20 school days per year and may require tutoring or
Nausea and vomiting
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Syndrome with Neuromuscular Disease."
American Journal of Medical Genetics
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Epilepsy: A Common Underlying Disorder?"
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Khasawinah, T. A., et al. "Preliminary Experience with
Dexmedetomidine in the Treatment of Cyclic Vomiting Syndrome."
American Journal of Therapeutics
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Li, B. U., and L. Misiewicz. "Cyclic Vomiting Syndrome: A Brain-Gut
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32 (September 2003): 997–1019.
Salpietro, C. D., et al. "A Mitochondrial DNA Mutation (A3243G
mtDNA) in a Family with Cyclic Vomiting."
European Journal of Pediatrics
162 (October 2003): 727–28.
Cyclic Vomiting Syndrome Association in the United States and Canada
3585 Cedar Hill Road, NW, Canal Winchester, OH 43110. Web site:
National Organization for Rare Disorders Inc. (NORD).
55 Kenosia Avenue, PO Box 1968, Danbury, CT 06813. Web site:
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J. Ricker Polsdorfer, MD