Arnold-Chiari 1 Decompression

Chiari 1 defect allowing cerebellar tonsils to herniate through base of skull (Foramen Magnum) Trauma causes additional swelling of brain which exacerbates the compression at the foramen. Emergency decompression by removing the upper cervical posterior laminae and portions of the Foramen Magnum rim. Consequently, the left cerebellar tonsil was also removed to further decompress brain stem.