Posterior fossa abnormalities in children with infantile spasms.

In order to explore possible pathophysiologic involvement of the brain stem in infantile spasms, we retrospectively compared clinical and electroencephalographic (EEG) features of 14 children with infantile spasms who had gross posterior fossa abnormalities on neuroimaging studies with 84 children with infantile spasms who had either normal neuroimaging (n = 19) or supratentorial abnormalities (n = 65). Children with posterior fossa abnormalities how lower mean initial and follow-up developmental quotients compared to those with normal imaging or supratentorial abnormalities alone. Age of onset of infantile spasms, latency to treatment, response to steroids, and follow-up EEG pattern were not significantly different among the three groups. Six children (6%) had Dandy-Walker cysts, an association rarely reported with infantile spasms. We conclude that the presence of posterior fossa abnormalities in patients with infantile spasms portends a relatively poor developmental outcome.