Snapshot A 9-month-old child presents with with a head circumfrence that is two standard deviations above the norm, frontal-bossing, and translucent skin. An MRI is ordered. Introduction Congenital structural defect of the cerebellum occuring during brain development including login to view 8 more bullets Three primary types of malformation are login to view 14 more bullets Arnold-Chiari syndrome is often associated with other pathology including hydrocephalus, syringomyelia, and spinal curvature Presentation Symptoms login to view 8 more bullets Physical exam login to view 4 more bullets IMAGING CT/MRI login to view 1 more bullet Differential Other developmental defects (neural tube defects), intrauterine trauma, cerebral palsy, Treatment Prevention login to view 2 more bullets Medical management login to view 2 more bullets Surgical intervention login to view 2 more bullets Complications Permanent paralysis Death as neonate or toddler Prognosis Range widely depending on type and severity of anatomic abnormality Some children with type I function normally, while type III has low survival rate