Cyclic vomiting syndrome

Overview

Cyclic vomiting syndrome (CVS) is a chronic functional disorder characterized by recurrent, stereotyped episodes of intense nausea and vomiting separated by symptom-free intervals. Each episode can last for hours to days and may require hospitalization in severe cases. Although more common in children, CVS also occurs in adults. The exact cause is unknown, and it often overlaps with other conditions such as migraines or gastrointestinal disorders. Proper diagnosis and management are key to improving quality of life and reducing healthcare visits.

Causes

The precise cause of CVS remains unclear, but several contributing factors have been identified. It is considered a functional brain-gut disorder with possible neurologic and genetic components. Commonly suspected causes or triggers include:

• Migraine association: CVS is thought to be related to migraines, especially in children with a family history of migraine headaches.

• Genetics: Mutations in mitochondrial DNA have been linked to some cases, suggesting a hereditary component.

• Stress and anxiety: Emotional stress is a frequent trigger for episodes.

• Dietary triggers: Such as chocolate, cheese, or caffeine in some individuals.

• Sleep disturbances: Irregular sleep patterns may initiate episodes.

• Infections or physical exhaustion: Viral illnesses or intense physical activity can trigger attacks.

Symptoms

The hallmark feature of CVS is recurrent, severe vomiting episodes that follow a predictable pattern. The condition typically progresses through four phases:

1. Prodrome phase: Characterized by nausea, sweating, and pale skin; the individual is usually aware an episode is about to start.

2. Vomiting phase: Repetitive, intense vomiting and retching, often occurring every few minutes for hours to days. Abdominal pain, diarrhea, and lethargy may accompany it.

3. Recovery phase: Vomiting subsides, and appetite returns. The individual often sleeps for long periods.

4. Well phase: A symptom-free period between episodes, which can last days to months.

Additional symptoms may include dizziness, sensitivity to light, headache, and dehydration due to fluid loss.

Diagnosis

There is no definitive test for CVS. Diagnosis is clinical and relies on the patient’s history and the exclusion of other conditions. Diagnostic steps include:

• Detailed medical history: Focus on the pattern and frequency of vomiting episodes and symptom-free periods.

• Rome IV criteria: Used to define functional gastrointestinal disorders like CVS.

• Physical examination and lab tests: To rule out metabolic, infectious, or structural causes.

• Imaging: Abdominal ultrasound or CT scan may be done if red flags like weight loss or blood in vomit are present.

• Upper endoscopy: To rule out gastrointestinal structural abnormalities in chronic cases.

• Psychological evaluation: May be recommended if anxiety or psychiatric comorbidities are suspected triggers.

Treatment

There is no cure for CVS, but treatment focuses on managing symptoms, preventing future episodes, and identifying triggers. Treatment options include:

• Acute management during episodes:

  • IV fluids and electrolyte replacement for dehydration

  • Anti-nausea medications (ondansetron, promethazine)

  • Pain relievers for abdominal discomfort

  • Triptans (like sumatriptan) for migraine-related CVS

• Prophylactic (preventive) treatment:

  • Amitriptyline or propranolol (especially in children)

  • Anti-seizure medications (e.g., topiramate) in some cases

  • Mitochondrial supplements like coenzyme Q10 and L-carnitine

• Lifestyle modifications: Regular sleep, stress reduction, hydration, and avoidance of known triggers

• Cognitive behavioral therapy (CBT): Can be helpful in managing stress-related components of the condition

Prognosis

The prognosis for individuals with CVS varies. Many children improve or outgrow the condition by adolescence, especially with migraine-related CVS. In adults, symptoms can be more persistent but often improve with proper treatment and lifestyle changes. Frequent episodes can affect quality of life, school or work attendance, and mental health. With early recognition and a comprehensive care plan, most patients experience significant reduction in episode frequency and severity.