I understand your concern.Dandy–Walker syndrome (DWS), is a congenital brain malformation involving the cerebellum and the fluid-filled spaces around it. A key feature of this syndrome is the complete absence of the part of the brain located between the two cerebellar hemispheres.Other brain malformations have been reported in people with Dandy-Walker syndrome. These malformations include a failure of the brain to divide properly into the right and left hemispheres (holoprosencephaly), underdeveloped or absent tissue connecting the left and right halves of the brain (agenesis of the corpus callosum), a sac-like protrusion of the brain through an opening at the back of the skull (occipital encephalocele), abnormal slits or clefts in the brain (schizencephaly), or a type of birth defect that occurs when the protective covering around the brain or spinal cord fails to close during development (neural tube defect). These additional brain malformations are associated with more severe signs and symptoms. I think I have not bored with medical jargon. In your case it could be protrusion from meninges under increased CSF pressure and only detailed test with Ct/ MRI and clinical examination can help/ Please consult your doctor for guidance. Regards