Cyclic vomiting syndrome
Cyclic vomiting syndrome is a chronic functional disorder of unknown etiology that is characterized by paroxysmal, recurrent episodes of vomiting. Episodes can last for hours or days. Cyclic vomiting syndrome may be related to migraines. Migraine-related mechanisms have been proposed. Patients with CVS have a significantly higher prevalence of family members with migraine headaches (82% vs 14% of control subjects with a chronic vomiting pattern). Furthermore, 28% of patients with CVS whose vomiting subsequently resolved developed migraine headaches. Approximately 80% of affected patients with family histories positive for migraine respond to antimigraine therapy. Mitochondrial DNA (mtDNA) mutations may be involved in the pathogenesis of CVS.
Treatment generally involves managing symptoms and lifestyle changes to help prevent the events that can trigger vomiting episodes. To prevent episodes from occurring, some individuals have been treated with certain anti-migraine medications, especially amitriptyline, as well as cyproheptadine (in preschool-aged children) or propranolol. Anti-migraine therapies seem particularly effective for individuals with a family history of migraine.
Research into cyclic vomiting syndrome is ongoing. Researchers are studying substances that block the actions of corticotrophin-releasing factor thereby reducing the body’s stress response (CRF antagonists). Newer anti-migraine, anti-seizure and anti-nausea drugs are also being studied as potential treatment options for individuals with cyclic vomiting syndrome.
The incidence of new cases of CVS was reported to be 3.15 per 100,000 children per year in a recent series of 1,647 children in Ireland. Similar to the gender profile in migraine headaches, there is a slight predominance of girls over boys (57:43), though, due to limited data, it is unknown whether this is also true in adults.