Cyclic Vomiting Syndrome

What happens in cyclic vomiting syndrome

CVS is thought to involve abnormal signaling between the brain and the gut, with links to the stress response system (hypothalamic-pituitary-adrenal axis), the autonomic nervous system and the endocannabinoid system. It shares many features with migraine: episodes, triggers, family history and response to migraine treatments. In children, it often evolves into migraine headaches later in life.

The four phases of CVS

Many people find that episodes start at the same time of day, often early morning, and last a similar time each time.

Symptoms during an episode

• severe nausea and repeated vomiting or retching
• abdominal pain
• lethargy; some people seem almost unresponsive
• pale skin, sweating, drooling
• headache, sensitivity to light and sound
• diarrhea or fever in some
• compulsive hot showers or baths for relief in some adults (also typical of cannabinoid hyperemesis syndrome)

Diagnostic criteria

Under the Rome IV criteria for adults:

• stereotyped episodes of vomiting with acute onset, lasting less than a week
• at least three separate episodes in the past year, and two in the past 6 months, at least a week apart
• no vomiting between episodes, although milder symptoms can occur

A personal or family history of migraine supports the diagnosis.

Triggers

• emotional stress, anxiety, and positive excitement (holidays, birthdays)
• lack of sleep
• infections such as colds or flu
• menstrual periods
• fasting or skipping meals
• certain foods: chocolate, cheese, caffeine, MSG
• physical exhaustion
• hot weather, motion sickness
• alcohol

Keeping a diary helps identify personal triggers.

CVS and cannabis

Heavy, long-term cannabis use can cause cannabinoid hyperemesis syndrome, which looks almost identical to CVS, with episodic vomiting and relief from hot showers. Cannabis may also worsen CVS. Stopping cannabis completely for at least several months is the only way to tell them apart and is recommended for anyone with recurrent vomiting episodes who uses it.

Diagnosis

There is no test that confirms CVS. Doctors take a detailed history of the episodes and rule out other causes:

• blood tests: blood count, electrolytes, kidney and liver function, glucose, lipase
• an upper endoscopy or imaging to exclude ulcers, obstruction or structural problems
• abdominal ultrasound or CT for kidney, gallbladder or bowel causes
• in children, tests for metabolic and mitochondrial disorders when features suggest them
• gastric emptying studies in some cases to distinguish gastroparesis
• morning cortisol if Addison's disease is possible
• brain imaging if there are neurological signs

Treatment

Preventing episodes

Recommended for people with moderate to severe CVS (for example, frequent or long episodes, or emergency visits):

• Amitriptyline: the first-line preventive medicine in adults; it takes several weeks to work.
• Alternatives: topiramate, anticonvulsants such as zonisamide or levetiracetam, aprepitant, and in children cyproheptadine or propranolol.
• Coenzyme Q10 and L-carnitine supplements: sometimes added, especially in children and those with suspected mitochondrial dysfunction.
• Treat anxiety and depression, which are common and can trigger episodes.

Stopping an episode early (abortive therapy)

Taken at the first sign of the prodrome:

• sumatriptan nasal spray
• an anti-nausea medicine such as ondansetron (dissolving tablet)
• aprepitant in some cases
• a sedating medicine to help sleep through the attack
• lying in a dark, quiet room

During a severe episode

Emergency or hospital care provides:

• intravenous fluids with glucose and electrolytes
• intravenous anti-nausea medicines
• sedation to rest the brain-gut system
• treatment of complications

Having a written emergency care plan from your specialist speeds treatment in the ER.

Lifestyle

• regular sleep and meals
• stress management, CBT or relaxation techniques
• avoiding known triggers, alcohol and cannabis
• staying well hydrated between episodes

Complications

• dehydration and electrolyte imbalance
• tears in the esophagus lining (Mallory-Weiss tears) causing vomiting of blood
• esophagitis and tooth enamel erosion
• missed school or work, anxiety and depression

Outlook

Many children grow out of CVS by their teens, though about half develop migraine. Adults often respond well to amitriptyline and trigger management, with fewer and shorter episodes. Early recognition avoids repeated unnecessary tests and emergency visits.

Frequently asked questions

What is cyclic vomiting syndrome?

It is a disorder in which people have repeated episodes of severe nausea and vomiting lasting hours to days, with weeks or months of normal health in between. Episodes tend to be similar each time. It is linked to migraine and to abnormal brain-gut signaling.

What triggers cyclic vomiting episodes?

Common triggers include stress, excitement, lack of sleep, infections, menstrual periods, fasting, certain foods such as chocolate or cheese, motion sickness and alcohol. Cannabis use can also trigger or mimic episodes. Keeping a diary helps identify personal triggers.

How is cyclic vomiting syndrome treated?

Treatment includes daily preventive medicine such as amitriptyline, rescue medicines taken at the first warning sign (for example, sumatriptan and an anti-nausea medicine), intravenous fluids during severe episodes, and avoiding triggers. Stopping cannabis is strongly advised.

What is the difference between CVS and cannabinoid hyperemesis syndrome?

They look very similar, with episodes of vomiting and relief from hot showers. Cannabinoid hyperemesis syndrome is caused by long-term heavy cannabis use and stops when cannabis is stopped completely. CVS continues regardless of cannabis use.

Do children grow out of cyclic vomiting syndrome?

Many do, often by adolescence. However, many go on to develop migraine headaches. Treatment and trigger management help reduce episodes in the meantime.