Basilar Invagination and Cranial Settling

Basilar impression represents the broader category of occipitocervical junction pathologies, including basilar impression, basilar invagination, and cranial settling. Basilar invagination results from migration of the entire spine into the skull base. Cranial settling is caused by C1–C2 instability, leading to upward migration and/or rotation of the C2 complex into the cranial vault. Platybasia results from deformation and flattening of the skull base. Many patients present with a combination of neck pain, myelopathy, and potentially lower cranial nerve dysfunction. Computed tomography and magnetic resonance imaging are used to clarify the complex osseous anatomy and compression of neural elements,. Patients with a reducible basilar invagination may be treated with posterior decompression and stabilization alone, while non-reducible or partially reducible invagination must be treated with anterior decompression and posterior stabilization. The goal of treatment is to prevent further neurological decline and provide adequate stabilization of the O-C junction.

Surgical Treatment of C2 Odontoid Process Intussusception in Combination with Type I Chiari Malformation

Type I Chiari malformation is often accompanied by congenital developmental abnormalities such as platybasia, basilar impression and C2 odontoid process retroflexion that may cause anterior compression of brainstem structures and upper cervical segments of spinal cord. Formerly the conventional method was posterior decompression even in presence of anterior brainstem compression. This article presents on a kinetic example the tactics of one-step treatment of patients with type I Chiari malformation accompanied by basilar impression and C2 odontoid process retroflexion via transoral approach only that was used for both decompression and C1-C2 segment anterior stabilization. Surgical intervention enabled to achieve the decompression of brainstem structures and upper cervical segments of spinal cord, normalization liquor dynamics and subsequent redislocation of cerebellar tonsils to normal position (above the Chamberlain line).

Surgical Treatment of C2 Odontoid Process Intussusception in Combination with Type I Chiari Malformation

Type I Chiari malformation is often accompanied by congenital developmental abnormalities such as platybasia, basilar impression and C2 odontoid process retroflexion that may cause anterior compression of brainstem structures and upper cervical segments of spinal cord. Formerly the conventional method was posterior decompression even in presence of anterior brainstem compression. This article presents on a kinetic example the tactics of one-step treatment of patients with type I Chiari malformation accompanied by basilar impression and C2 odontoid process retroflexion via transoral approach only that was used for both decompression and C1-C2 segment anterior stabilization. Surgical intervention enabled to achieve the decompression of brainstem structures and upper cervical segments of spinal cord, normalization liquor dynamics and subsequent redislocation of cerebellar tonsils to normal position (above the Chamberlain line).