Which of the following statements about Dandy-Walker syndrome are true and which are false? 1 Most common posterior fossa malformation 2 Consists of a cystic expansion of 4th ventricle in the posterior fossa & midline cerebellar hypoplasia 3 Triad of Hypoplasia of vermis + Cephalad rotation of the vermian remnant & cystic dilatation of 4th ventricle extending posteriorly + Small posterior fossa 4 Most common manifestation is Macrocephaly 5 Managed by shunting the cystic cavity

DANDY- WALKER MALFORMATION - Mc posterior fossa malformation - Prevalence: 1 per 30,000 live bihs - Consists of a cystic expansion of 4th ventricle in the posterior fossa &midline cerebellar Hypoplasia - Results from a developmental failure of the roof of the 4th ventricle during embryogenesis. Dandy-Walker Malformation is characterized by the traid of - Hypoplasia of vermis - Cephalad rotation of the vermian remnant & cystic dilatation of 4th ventricle extending posteriorly - Enlarged posterior fossa with torcular-lambdoid inversion Clinical Features - MC manifestation: Macrocephaly (80% cases);Associated withhydrocephalus (90% cases) - Infants present with a rapid increase in head size & prominent occiput. - Transillumination of the skill may be positive. - Most children have evidence of long-tract signs, cerebellar ataxia, and delayed motor &cognitive milestones, probably due to the associated structural anomalies Associations - CNS abnormalities are present in 70% cases (i.e.Agenesisof the posterior cerebellar vermis & corpus callosumQ. Coical dysplasia, polymicrogyria) Diagnosis - IOC for diagnosis: MRI Treatment: Managed by shunting the cystic cavity