Description

• An idiopathic chronic functional GI disorder characterized by discrete, recurrent, stereotypical paroxysmal episodes of high-intensity nausea and vomiting lasting hours to days
• Subsets
  • Cyclic vomiting syndrome (CVS) plus two or more neuromuscular disorders in association
  • Catamenial CVS: associated with menstrual cycle
  • Note: Cannabis hyperemesis syndrome (CHS) is distinct from CVS.
• CVS has four distinct phases:
  • Interepisodic: symptom-free period
  • Prodromal: minutes to hours of nausea with or without abdominal pain
  • Vomiting: hours to days
  • Recovery: Nausea remits and patient recovers appetite, strength, and energy (1)[B].

Epidemiology

Incidence

• 3 per 100,000 annually in children
• Limited data in adults

Prevalence

• 0.04–2% in general population
• 1–2% in children (2)
• Female > male (55:45)
• More common in children; mean age of diagnosis is 35 years in adults and ages 3 to 7 in children.
• Average of 3 years from symptom onset to diagnosis

Etiology and Pathophysiology

• Strong link between CVS and migraine: similar symptoms, frequent family history of migraines, and effectiveness of antimigraine therapy
• One proposed mechanism:
  • Heightened neuronal excitability owing to enhanced ion permeability, mitochondrial deficits, or hormonal state → increased susceptibility to physical or psychological trigger → release of corticotropin-releasing factor (CRF) → vomiting
  • Vomiting perpetuated by altered brainstem regulation → sustained vomiting
• Possible maternal inheritance, based on family history of migraines and link to mitochondrial DNA (mtDNA) mutations
• Multiple theories:
  • GI motility dysfunction
  • Autonomic dysfunction: sympathetic (1)[B]
  • Food allergy or intolerance

Genetics

• Likely matrilineal inheritance, especially with childhood onset
• A3243G or other mtDNA mutations including mitochondrial dysfunction
• Ion channel mutations
• Several polymorphisms have been identified. 165119T more common in children with CVS

Risk Factors

• Family history of migraine headaches
• Depression and/or anxiety
• Chronic cannabis use
• Possibly food allergies
• Hypothalamic-pituitary-adrenal axis dysfunction

General Prevention

• No primary prevention measures exist.
• Secondary prevention of attacks relies on multidisciplinary approach to trigger avoidance, comorbidity treatment, and prophylactic medication use.

Commonly Associated Conditions

• Irritable bowel syndrome (67%)
• Headaches (52%)
• Motion sickness (46%)
• Migraines (11–40%)
• Seizure disorder (5.6%)
• Cannabis use