Updated Evidence Regarding Chiari Malformation Type I and Management Options

acterized by herniation of the rhombencephalic structures (cerebellum and brainstem) from the posterior fossa. Originally characterized in postmortem examinations performed by Dr. Hans Chiari in the late 1800s, the term “Chiari malformation” has since expanded to encompass multiple different diagnoses. Chiari malformation types II, III, and IV refer to secondary herniation of the cerebellar vermis and brainstem due to myelomeningocele (type II), herniation of the hindbrain into encephalocele defects (type III), and cerebellar aplasia (type IV). Chiari malformation type I is the most common, and its presentation and management have been the focus of this review.