Abnormality of the Central Canal of the Spinal Cord in Syringomyelia in a Patient With a Basal Skull Malformation

The aim of this study is to analyze the association between a deformity of the cranial portion of the central spinal canal and syringomyelia in patients with a Chiari-type malformation of the craniocervical junction. The investigators hypothesize that Chiari malformation, defined by the herniation of the cerebellar tonsils through the foramen magnum, may be responsible for a deformation of the cranial portion of the central spinal canal, and that this deformation is associated with the presence of syringomyelia in patients with this malformation.

Inclusion Criteria: * Adult patients being treated for Chiari malformation or syringomyelia at Bordeaux University Hospital * Patients admitted for an initial surgical consultation regarding Chiari malformation with or without syringomyelia at Bordeaux University Hospital * Individuals enrolled in or covered by a social security program. * Free, informed, and express consent (confirmed in writing) (no later than the day of enrollment and prior to any examination required by the study). Exclusion Criteria: * Pregnant or breastfeeding patients * Contraindications to MRI * Individuals deprived of their liberty by judicial or administrative order, * Adults subject to legal protective measures (guardianship, conservatorship, judicial protection). * Patients who have previously undergone surgery for a Chiari malformation or a posterior fossa malformation