Chiari malformation is a disorder characterized by a disproportion between the size of the posterior fossa and its content, the cerebellum. Due to the lack of space, the lower portion of the cerebellum, the cerebellar tonsils, can herniate through the foramen magnum into the cervical spinal canal.
Surgical intervention is the only possible treatment and it consists in performing a reconstruction of the posterior fossa.
It is usually a congenital disorder that can be associated with bone abnormalities at the craniocervical junction. Surgical intervention consists in performing a suboccipital craniectomy associated sometimes with a high cervical laminectomy, depending on the severity of the tonsillar herniation. In addition, duroplasty will be performed to let the cerebellum return to its normal position. If there is instability of the craniocervical junction, spinal fusion may be necessary. In certain cases, it may be associated with an abnormality in the cerebrospinal fluid circulation that may cause hydrocephalus or syringomyelia. This condition might require a cerebrospinal fluid shunt (ventriculoperitoneal or syringosubachnoid shunt)
Treatment of Chiari malformation with reconstruction of the posterior fossa
Programmable and non-programmable ventriculoperitoneal shunt