Electrogastrography in cyclic vomiting syndrome.

Children with cyclic vomiting syndrome have a characteristic periodicity, and this could be due to abnormal gastric myoelectrical activity detectable by cutaneous electrogastrography (EGG). Fifteen children, aged 4-15 years, with CVS (eight symptomatic and seven asymptomatic at the time of study) underwent EGG and were compared to five normal and four disease control children. The relative tachygastria activity (RTA) or power ratio was calculated in each group. Five of the eight symptomatic CVS children showed marked episodes of tachygastria preprandially and all showed tachygastria postprandially. The asymptomatic CVS children showed tachygastria only postprandially after the test meal. RTA index and or power ratio of symptomatic children was significantly different from the asymptomatic CVS children (P = 0.001), normal (P = 0.007) and disease control children (P = 0.006). In a subsequent study, 2-hr gastric emptying 99mTc scintiscans were performed in 28 CVS children and compared to eight healthy control children. Twelve of 16 CVS children (75%) showed abnormal gastric emptying, and 7 of 28 (25%) showed abnormal EGG with significant tachygastria. The CVS children had significantly higher RTA both preprandially (P < 0.05) and postprandially (P < 0.05). Our results demonstrate that accelerated gastric rhythm was seen during the acute episodes of half of the CVS patients studied. Abnormal EGGs and higher RTA or power ratios were associated with delayed gastric emptying in the CVS children. Abnormal gastric myoelectrical activity may play a role in the pathogenesis of CVS syndrome.