Review article: cyclic vomiting syndrome in adults - rediscovering and redefining an old entity

Background Cyclic vomiting syndrome is a disorder characterised by recurrent episodes of severe nausea and vomiting separated by symptom-free periods. Aims To review the history, epidemiology, clinical aspects, pathophysiology, diagnosis and treatments of adult cyclic vomiting syndrome as well as to identify areas for further clinical research and the unanswered questions in this field. Methods We conducted a PubMed search using such keywords as cyclic vomiting syndrome; nausea; vomiting; pathophysiology; diagnosis; treatment; trigger factors; gastric emptying test; autonomic nerve function test; gastrointestinal hormones; outcome and natural history and combined this information with the knowledge and extensive clinical research and publications from the authors. Results Available data show that in adult cyclic vomiting syndrome, severe epigastric and sometimes diffuse abdominal pain accompanies most cycles of nausea and vomiting interspersed with periods of symptomatic remission. Psychological disorders, specifically anxiety and depression are common, and gastric emptying is actually rapid in approximately 60% of patients and normal in the remainder. There is an impressive and sustained response to high-dose tricyclic antidepressants. In up to 15% who are regarded as poor responders to tricyclic antidepressants, a predictable profile can be identified related to co-existing psychological disorders, marijuana use, poorly controlled migraine headache or chronic narcotic use. Conclusions Cyclic vomiting syndrome in adults is an entity that is being increasingly recognised, but the need to educate Internists, Gastroenterologists and Emergency Department staff remains an ongoing challenge.