Dandy-Walker Phenotype with Brainstem Involvement: 2 Distinct Subgroups with Different Prognosis.

Additional brainstem malformations in patients with the Dandy-Walker phenotype can be divided into 2 major subgroups: mild and severe. The severe form, though less prevalent, has characteristic imaging features, including tegmental folding, bumps, and clefts, and is directly associated with a more severe clinical presentation and increased mortality.