By: Richard G. Boles, M.D.; March 1, 2021

Many individuals suffer from an unexplained condition that is characterized by recurrent, prolonged attacks of severe nausea and vomiting, sometimes coupled with fatigue, fever, and gastrointestinal discomfort.  Although the exact prevalence is unknown, estimates in recent studies suggest the 3 in every 100,000 people are affected with this condition, with females having a slight pre-dominance over males.
The possible diagnoses for an individual presenting with prolonged attacks of severe nausea and vomiting are many and varied, and Cyclic Vomiting Syndrome (CVS) should be considered. 

What is CVS? Like most diagnoses, CVS is defined based on signs and symptoms, not on any underlying cause. People with CVS have episodes of nausea and vomiting. Episodes are stereotypical in that they all are fairly similar in each individual, although episodes might vary in severity and length. Of course, in CVS there are multiple episodes, at least 3 or 5 depending on the specific diagnostic criteria used. Some CVS sufferers have a degree of nausea with or without vomiting between episodes, but in CVS the degree of severity is always much greater during episodes than in-between. If you meet these stipulations, then you have CVS.

Some people have episodes like clockwork, with every month being common, especially in adolescent or adult females. Some others have episodes associated with triggers, which include viral illnesses, fasting, over-exercise, lack of sleep, or stress. Especially important is the role of positive stress as triggers, such as associated with parties and vacations. Still others have episodes apparently at random. Episodes can last for hours up to a week or longer, but one to a few days is about average. CVS is not rare, and per studies is present in 1 to 2% of school-aged children. However, CVS can appear at any age, from infancy to the elderly. Both boys and girls are affected.

Additional symptoms may occur during an episode including fatigue, tiredness, fever, and drooling. Gastrointestinal symptoms such as severe abdominal pain, diarrhea, and retching (gagging) are not uncommon. Emesis may be bilious (green or yellow). Repetitive vomiting may cause loss of fluids leading to dehydration. Affected individuals have a reduced appetite and weight loss may occur. Some individuals may exhibit a variety of migraine-like neurological symptoms including headaches, abnormal sensitivity to light (photophobia), increased sensitivity to sound (phonophobia), and dizziness or vertigo.

What causes CVS? The vast majority of CVS causes are “functional”, in which it is not the structure of cells and tissues but their abnormal function that leads to disease. Episodes are often thought of being “migraine-like”, and in many cases the patient and/or family members often do have migraine headaches.

However, rarely are there “structural” causes for CVS such as malrotation of the intestines, obstruction of one kidney, or a brain mass. While these causes are quite uncommon, in many cases physicians appropriately order imaging tests to look for them.

CVS occasionally affects more than one family member, but while relatives only occasionally have CVS, patients and their relatives frequently have other “functional” conditions such as migraine headache, other pain syndromes such as fibromyalgia, irritable bowel, gastroparesis, chronic fatigue, and many others. This suggests that certain genes act to predispose some people to develop CVS and other functional conditions.

An additional factor that oftentimes is associated with the development of CVS include dysfunction of the autonomic nervous system. The autonomic nervous system controls or regulates certain involuntary body functions including heart rate, blood pressure, sweating, the production and release of certain hormones, and bowel and bladder control. Autonomic “functional” disturbances are common during episodes, including fever, pallor, tachycardia, high blood pressure and urinary retention. Vomiting itself is an autonomic disturbance. Autonomic disturbances can also occur between episodes, such as complex regional pain condition, syncope (fainting), and disorders of gastrointestinal motility. The latter are particular common, and can include gastroesophageal reflux (GERD), delayed gastric emptying (resulting in feeling full early during meals), and irritable bowel (constipation, diarrhea, abdominal pain, and/or bloating).

Researchers have also learned that testing reveals signs of abnormal energy metabolism in CVS. Genetic variants in the mitochondrial DNA (mtDNA) and the nuclear DNA (chromosomes) can lead to mitochondrial dysfunction and predispose towards the development of CVS. Because mitochondria (the cell’s power plant) in particularly important in nerve tissues, defective mitochondrial energy production may lead to an energy shortage that affects nerve function, especially the autonomic nerves that control the gut. The stressful situations that serve as triggers for CVS also necessitate high energy demands that puts additional stress on affected mitochondria.

Additional conditions often seen in those with CVS include anxiety, depression, epilepsy, attention deficit hyperactivity disorder (ADHD), autistic spectrum disorders, and learning disabilities.

For more information about CVS and various therapies, please visit the Cyclic Vomiting Syndrome Association Website

Disclosure: Dr. Boles is the Chief Medical & Scientific Officer for NeuroNeeds LLC, the start-up company that makes SpectrumNeeds®, EnergyNeeds®, QNeeds®, and CalmNeeds®.  You are under no obligation to purchase this or any products, whether recommended by Dr. Boles or another health care provider. As always, it is recommended that you contact your physician regarding these products and all other changes to disease management.

The Content within this article and NeuroNews Blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this Blog.