Relationship between cerebellar appearance and function in children with Dandy-Walker syndrome.

In children with Dandy-Walker syndrome (DWS), the relationship between cerebellar appearance on imaging and either cerebellar function or intellect is unknown. To evaluate those relationships, we retrospectively studied 20 patients with DWS treated in our institution between 1978 and 1994. The patients were treated with ventriculoperitoneal, cystoperitoneal, or ventriculocystoperitoneal shunts. Intellectual and cerebellar function were determined from neurological and developmental testing. Cerebellar development was evaluated by measuring cerebellar and posterior fossa volumes from computed tomography images; the ratio of cerebellar size to posterior fossa size was considered to reflect cerebellar development. The cerebellar function was normal in 50% and the intellectual function in 45% of the patients. There was no correlation between cerebellar size and intellectual development or cerebellar function. There was also no correlation between the type of shunt and the subsequent cerebellar size. We conclude that there is no relationship between the cerebellar development evident on computed tomography scans and the cerebellar or the intellectual function of children with DWS. We, therefore, infer that treatment of Dandy-Walker cysts with posterior fossa shunts is unlikely to enhance the cerebellar function.