2022 Volume 47 Issue 3 Pages 325-329
Chiari malformation type I (CM I) causes various morphological malformations in the posterior fossa. Here, we present two cases of CM I with internal occipital crest (IOC) duplication wherein the patients underwent surgery.
Case 1: A 3-year-old girl was diagnosed with CM I due to enlarged head circumference and developmental retardation. Computed tomography (CT) revealed IOC duplication. The patient was diagnosed with symptomatic CM I, which became a bony decompression. Foramen magnum decompression and duplicated IOC ostectomy were performed with the primary goal of IOC duplication removal. The patient's postoperative course was good.
Case 2: An 18-month-old girl was diagnosed with CM I due to developmental retardation. A head CT revealed IOC duplication. Foramen magnum decompression was performed, and the patient's postoperative course was good.
Wide foramen magnum ostectomy is important for decompression; however, in case with duplicated IOC, while the cerebellar tonsils are compressed, its ostectomy is also necessary for the decompression.
