The precipitants and etiological factors in 32 patients aged 2 - 22 years (mean, 12 years) with cyclic vomiting syndrome (CVS) compared to 64 controls were evaluated by parental questionnaire at the Princess Margaret Hospital for Children, Perth, Australia. The most prevalent precipitants were stress (47%), infections (44%), and foods (28%). Accompanying features included headache (59%) and behavioral withdrawal (59%), lethargy (56%) and crying (34%). Migraine occurred more frequently in association with CVS than in controls (38% cf 9%). Other medical problems found more frequently in the CVS group were forceps delivery, developmental delay, coordination difficulties, and gastro-esophageal reflux. Antiemetic medications utilized in 28 were useful in only 7 (28%). Antihistamines, antimigraine drugs and anticonvulsants had been prescribed in too few patients to permit evaluation. CVS was considered a migraine variant. 
COMMENT. Migraine is one of the many proposed theories in etiology of cyclic vomiting. In this Australian series, migraine was diagnosed using parental questionnaires in 38% compared to 9% of controls. Recurrent abdominal pain, a common presenting symptom among children with migraine occurred in only 21%, a frequency not significantly different from the 16% in controls. Epilepsy was reported in only one patient, but the incidence of accompanying behavioral symptoms during attacks was remarkably high. Electroencephalograms might have uncovered cases of partial complex temporal lobe involvement and ictus emeticus.
In a report of 33 children with cyclic vomiting from the Children’s Medical Center, Boston, 7 (21%) had a history of complex partial or generalized epilepsy, and 25 (76%) had epileptiform EEGs, some temporal in localization, compatible with a diagnosis of epilepsy . In reviewing my paper, I find that 39% of the patients had a family history of migraine and while phenytoin was effective in prevention of cyclic vomiting, suppositories of ergotamine tartrate with caffeine helped in their alleviation. In this group of patients seen at an epilepsy center, the diagnosis of ictus emeticus was firm in 21%, and suggestive in the remainder. The nondominant temporal lobe is involved in the epileptic discharge in some reports of ictus emeticus. I concede that migraine is a possible alternative explanation for some of the cases and others I have encountered more recently are entirely idiopathic. This sometimes most distressing and protracted cyclic vomiting requires further study, both neurological and metabolic. (See Progress in Pediatric Neurology III, (PPN III) 1997;pp51-54, for further articles on ictus emeticus and autonomic epilepsy).