Playing Dr. Miranda Bailey on TV’s Grey’s Anatomy, actress Chandra Wilson has seen plenty of staged medical emergencies over the past six years. But Wilson recently faced a real-life medical drama that hit very close to home. Seemingly out of the blue, Wilson’s teenage daughter, Sarina, began having bouts of intense nausea and uncontrollable vomiting. Doctors ran a series of gastrointestinal tests to see what was attacking the girl’s stomach, but the root of her illness remained a mystery for months.

As it turns out, doctors couldn’t find a problem with Sarina’s stomach because there wasn’t one; her brain was likely to blame for her abdominal discomfort.

After much testing, doctors diagnosed Sarina with cyclical vomiting syndrome (CVS), a disorder that is believed to occur neurologically but trigger symptoms in the belly. Even though her stomach was probably perfectly healthy, Sarina’s brain was sending signals to her body that caused intense vomiting. The idea of a neurological disorder affecting the body like a stomach flu may seem odd to some, but it’s not unprecedented in medicine.

Athos Bousvaros, MD, MPH

“CVS is like chemotherapy in the way it affects a person’s stomach via his or her brain,” says Athos Bousvaros, MD, MPH of Children’s Hospital Boston’s Gastroenterology and Child Nutrition Program. “Chemo doesn’t affect the stomach directly, but affects a part of the brain called the chemoreceptor trigger zone. The trigger zone then activates a part of the brain called the vomiting center, which sends signals to the body that causes the person to throw up. CVS works in a similar way.”

Vomiting can be the result of many medical conditions, not just CVS, which is why it’s often misdiagnosed as a gastrointestinal problem. What doctors do know for sure is that CVS can be differentiated from other conditions that cause vomiting by three main features:

  • The attacks are sudden, with an abrupt start and end point
  • The symptoms displayed during an attack tend to be similar to previous attacks
  • Once the episode is over the patient quickly feels well again, as if she had never been sick at all

It can be a very uncomfortable condition and often goes for months before being properly diagnosed. So what is it about CVS that makes it so hard to pinpoint?

First, there are no tests for cyclical vomiting syndrome, so doctors are forced to spend a lot of time determining what isn’t causing the symptoms. Unfortunately, diagnosis by process of elimination can take a long time.

Also, the fact that CVS attacks start and end so abruptly makes them hard to study. During a CVS attack, a patient is usually too sick to get to a hospital, so by the time they see a doctor they’re no longer experiencing symptoms. Physicians are left trying to identify an illness even though they can’t test for it directly or witness any of its symptoms.

Much about CVS remains a mystery

“CVS is tough to diagnose because it’s a rare syndrome, with multiple symptoms, and there’s is still so much we don’t know about it,” says Bousvaros. “At this point a careful evaluation of the patient’s past medical history is the most accurate way to recognize CVS.”

And CVS isn’t just hard to diagnose; it can be tough to treat once identified. Doctors have found that a proactive approach to controlling CVS works best, but only when the symptoms occur with some frequency. In these cases the patient takes a small dosage of medicine daily, even when they’re not experiencing symptoms, and do so until their attacks become rare to non-existent.

This style of treatment worked for Sarina, but may not be right for every child with CVS. Speaking with the right doctor, like a pediatric neurologist or gastroenterologist can help parents understand what treatment is right for their child if they have CVS or CVS like symptoms. “The most important thing to do is to find a physician who can take a careful history of your child and determine if it’s consistent with CVS,” says Bousvaros. “After the history, examination, and testing, if your physicians feel that CVS is likely, they will discuss the right therapy with you.”