Dandy-walker syndrome revisited

The Dandy-Walker syndrome is said to be associated with a high incidence of mental retardation and motor dysfunction leading some to suggest termination of the affected fetus in utero. Since this view seemed contrary to our experience, we reviewed 19 patients with the Dandy-Walker syndrome diagnosed from 1966 to 1983. Thirteen patients with Dandy-Walker syndrome were diagnosed before 6 months of age and followed for more than 2 years (mean: 10 years). In the absence of other associated major abnormalities, 7 of 8 (88%) are functioning well and have attended regular schools. Two of these seven have had special help with isolated learning problems. None of these patients have significant motor disability. One additional patient with normal intellectual and motor function died of acute shunt malfunction. In the remaining 4 patients with Dandy-Walker-associated abnormalities, 3 (75%) have severe intellectual retardation and spastic cerebral palsy. Five of six patients (83%) with Dandy-Walker syndrome diagnosed after 6 months of age are normal. The outcome of patients with Dandy-Walker syndrome appears far better than previously reported. The Dandy-Walker syndrome (DWS) is defined as a congenital malformation of structures in the posterior fossa and is characterized by: (1) cystic dilatation of the fourth ventricle, (2) hypoplasia or agenesis of the cerebellar vermis, and (3) hydrocephalus which is either congenital or of later onset [1, 2], Associated central nervous system malformations often found at autopsy [4] in patients with the diagnosis of DWS include: heterotopias, agyria, polymicrogyria, agenesis of the corpus callosum, aqueductal stenosis, and syringomyelia. The etiology and pathogenesis of this condition are not yet determined, but the presence of associated abnormalities is suggestive of an early embryonal developmental disturbance affecting more than just posterior fossa structures [6]. The DWS is said to be associated with a high incidence of motor dysfunction, mental retardation and mortality [1-5, 7] leading some to suggest that the prognosis for normal intellectual development is poor [11], This study addresses the outcome of children with the DWS diagnosed at the Johns Hopkins Hospital from 1966 to 1983. Their outcome appears far better than previously reported.