Chiari Malformation with Syringomyelia

Chiari I malformation (CIM) is defined by pathological herniation of the cerebellar tonsils below the foramen magnum. Operative intervention for CIM is generally undertaken to treat neurological deficits associated with tonsillar herniation or with associated syringomyelia. A complete brain and spine MRI is indicated to rule out associated abnormalities and to identify and the presence and extent of syringomyelia. The type of surgical decompression remains controversial but may include bone-only decompression, bony decompression followed by duraplasty, and bony decompression followed by duraplasty and tonsillar shrinkage. Post-operative monitoring for CSF leakage, inadequate decompression, subtle chronic craniocervical instability, and hydrocephalus is critical.