title: Acquired Chiari malformation secondary to atlantoaxial vertical subluxation in a patient with rheumatoid arthritis combined with atlanto-occipital assimilation.
abstract: A 65-year-old woman with a history of rheumatoid arthritis presented with a rare case of acquired Chiari malformation secondary to atlantoaxial vertical subluxation, associated with congenital atlanto-occipital assimilation. Syringomyelia and tetraparesis improved immediately after posterior fossa decompression and simultaneous occipito-cervical junction fusion. The progression of acquired Chiari malformation is not well known. We concluded that coexisting assimilation accelerated crowded foramen magnum following atlantoaxial vertical subluxation and induced acquired Chiari malformation over the course of a few years.
authors.affiliation: Department of Neurosurgery, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Yuiko
authors.initials: Y
authors.lastname: Kimura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Seichi
authors.forename: Akira
authors.initials: A
authors.lastname: Gomi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kojima
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Inoue
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kimura
mesh_terms: D001139:Arnold-Chiari Malformation / Q000209:etiology*; D001172:Arthritis, Rheumatoid / Q000150:complications*; D001268:Atlanto-Axial Joint / Q000002:abnormalities / Q000473:pathology* / Q000601:surgery; D001863:Bone Screws; D016025:Bone Transplantation; D000013:Congenital Abnormalities / Q000473:pathology*; D019299:Decompression, Surgical; D018450:Disease Progression; D004677:Encephalocele / Q000209:etiology; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009777:Occipital Bone / Q000601:surgery; D011782:Quadriplegia / Q000209:etiology; D012074:Remission Induction; D013123:Spinal Fusion; D013595:Syringomyelia / Q000209:etiology