The contribution of prenatal diagnosis to the understanding of malformative intracranial cysts: state of the art

This review evaluates the contribution of prenatal diagnosis to the underst anding of intracranial cysts. We describe the outcome of 54 fetuses in whic h prenatal investigations indicated the presence of such lesions. The cysts were diagnosed between 20 and 30 weeks of gestation. Most (63%) were supra tentorial and interhemispheric. There was only a single sylvian cyst. In th e infratentorial compartment, median retrocerebellar cysts were predominant . Incisural cysts accounted for 14.8% of the series. Nine pregnancies were interrupted because of the presence of associated brain disorders. Forty-fi ve children are alive. Thirty-four had neuropsychological tests. Cysts rare ly progressed, most frequently stabilized and often regressed postnatally. Hydrocephalus was rare. In two cases delivery was precipitated at 36 weeks to allow urgent treatment of rapidly evolving cysts. Thirteen children (28. 2%) were treated postnatally, in general for de veloping cysts. The median follow-up for the whole series exceeds 4 years. Behavior, neurological deve lopment, and intelligence are normal in 88% of the cases, and 91% have a no rmal neurological status. Prognosis at the time of the prenatal consultatio n was correct in 89% of the cases. We emphasize the value of prenatal magne tic resonance imaging and karyotype studies to Limit risks of incorrect pro gnosis.