David R. Fleisher, of the University of Missouri School of Medicine in Columbia, Missouri in the US, and colleagues conducted a retrospective study of 41 adults patients they had seen from 1994 to 2003 who were suffering from CVS. The patients were selected from a cohort of 237 children and adults, and were between 20 and 49 years of age at the time of consultation.
CVS is a disorder whereby sufferers experience recurrent stereotypic episodes of incapacitating nausea, vomiting and other symptoms, separated by weeks or months of comparative wellness. Sufferers typically experience between 6 and 12 episodes a year that are completely incapacitating.
The disorder appears to originate in the central nervous system, not the abdomen, say the authors. Fleisher and colleagues found that 28 out of 40 patients experienced migraine headaches during or between episodes. 93% of patients experienced a phase known as the prodrome, indicating the approach of an episode of CVS. Panic attacks were also "surprisingly prevalent". The authors found that "in two thirds of our adult CVS patients, panic attacks triggered cyclic vomiting episodes". Most patients had elements of both migraine tendency and anxiety complicated by panic attacks.
While panic attacks are uncommon in pre-adolescent children, children suffering from CVS are known to have higher rates of anxiety than children generally.
Fleisher and colleagues hypothesise that adult patients suffering from CVS may experience two routes to an attack, with different causes. "One involves whatever creates attacks of migraine or migraine equivalents in patients with migraine diathesesis. The other involves whatever creates anxiety attacks in patients with anxiety disorders."
The diagnosis can be made only by recognition of its clinical pattern over time. CVS is often missed because its clinical features are not widely known. Of the 41 patients reported, 16 patients underwent 17 surgeries, including 10 cholecystectomies, all of which proved futile.
Cyclical Vomiting Syndrome in 41 Adults: the illness, the patients and problems of management
David R Fleisher, Blake Gornowicz, Kathleen Adams, Richard Burch and Edward J Feldman BMC Medicine 2005, 3:20 (21 December 2005)