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C-MAVEM · Chiari and spinal and spinal cord malformations, and syringomyelia

The Neurosurgery is certified as a Center of Competence for the management of Chiari malformations, rare spinal and spinal cord malformations and syringomyelia for the western region.

The rare diseases competence center aims to provide care and monitoring of patients as close as possible to their homes. Indeed, the CCMR participates in the diagnosis and implements therapy when it is available and organizes the care of patients in conjunction with the C-MAVEM Rare Disease Reference Center and with all the actors involved in the treatment. identified in charge of proximity. The competence center follows the existing recommendations and protocols of its reference center.

  • Pathologies

    Chiari malformation

    The term “ Chiari malformations ” brings together a heterogeneous set of malformations of the occipitocervical hinge characterized by a descent of the cerebellar tonsils through the foramen magnum.

    Among these malformations, Chiari malformation type I (Chiari Malformation type I, CMI) is characterized by a descent of the tonsils greater than or equal to 5 mm, most often in relation to a reduction in the volume of the posterior fossa (Speer et al ., 2003). They are the main cause of syringomyelia, that is to say the progressive development of an intramedullary fluid cavity.

    Chiari type II malformations are characterized by descent of the cerebellar vermis, the 4th ventricle and the bulb, and are most often associated with myelomeningocele and hydrocephalus; they are discovered antenatally or at birth. Other types of Chiari malformations (type III, IV, 0) have been described but remain anecdotal (Speer et al., 2003).


    Syringomyelia is characterized by the presence of cavities (syrinxes) containing cerebrospinal fluid (CSF) inside the spinal cord. The appearance of syringomyelia can be linked to a known cause (secondary syringomyelia) or, more rarely, without a cause being found (primary syringomyelia) . The prevalence is estimated at 8.4/100,000. Cases of autosomal recessive familial syringomyelia have been described with an estimated incidence of 2% of all cases of syringomyelia. The vast majority of cases of syringomyelia are therefore not genetic.

    Vertebro-medullary malformations (Dysraphisms, Spina Bifida)

    The term “Spina Bifida” previously used is gradually tending to be replaced by that of “dysraphism” which brings together all forms of this pathology, from the most minimal to the most extensive.

    Dysraphism is linked to incomplete development of the spinal column leading to a dorsal (posterior) of the vertebrae which is associated with more or less pronounced damage to the spinal cord.

    We distinguish between open dysraphisms, or “spina bifida aperta”, lacking skin coverage (e.g. myelomeningocele, myelocele) , and closed dysraphisms, or “spina bifida occulta”, in which the malformation is covered (e.g. terminal cone lipoma, dermal sinus, etc.).

    Dysraphisms are most often located in the lumbar or sacral part of the spine, on 2 to 3 vertebrae, but can sometimes also affect the thoracic or cervical part.