Neurospine.  2019 Jun;16(2):195-206. 10.14245/ns.1938192.096.

Is Cervical Stabilization for All Cases of Chiari-I Malformation an Overkill? Evidence Speaks Louder Than Words!

Affiliations
  • 1Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India. sbehari27@gmail.com

Abstract

Chiari I malformation is characterized by the downward displacement of cerebellar tonsils through the foramen magnum. While discussing the treatment options for Chiari I malformation, the points of focus include: (1) Has the well-established procedure of posterior fossa decompression become outdated and has been replaced by posterior C1-2 stabilization in every case? (2) In case posterior stabilization is required, should a C1-2 stabilization, rather than an occipitocervical fusion, be the only procedure recommended? The review of literature revealed that when there is bony instability like atlantoaxial dislocation (AAD), occipito-atlanto-axial facet joint asymmetry or basilar invagination (BI) associated with Chiari I malformation, one should address the anterior bony compression as well as perform stabilization. This takes care of the compromised canal at the foramen magnum and re-establishes the cerebrospinal fluid flow along the craniospinal axis; and also provides treatment for CVJ instability. In the cases with a pure Chiari I malformation without AAD or BI and with completely symmetrical C1-2 joints, however, posterior fossa decompression with or without duroplasty is sufficient to bring about neurological improvement. The latter subset of cases with pure Chiari I malformation have, thus, shown significant (>70%) rates of neurological improvement with posterior fossa decompression alone. A C1-2 posterior stabilization is a more stable construct due to the strong bony purchase provided by the C1-2 lateral masses and the short lever arm of the construct. However, in the cases with significant bleeding from paravertebral venous plexus; a very high BI, condylar hypoplasia and occipitalized atlas; gross C1-2 rotation or vertical C1-2 joints with unilateral C1 or C2 facet hypoplasia, as well as the presence of subaxial scoliosis; maldevelopment of the lateral masses and facet joints (as in very young patients); or, the artery lying just posterior to the C1-2 facet joint capsule (being endangered by the C1-2 stabilization procedure), it may be safer to perform an occipitocervical rather than a C1-2 fusion.

Keyword

Chiari I malformation; Atlantoaxial dislocation; Basilar invagination; Surgical protocol; Posterior stabilization; Craniovertebral junction

MeSH Terms

Arm
Arteries
Cerebrospinal Fluid
Deception
Decompression
Dislocations
Foramen Magnum
Hemorrhage
Joints
Palatine Tonsil
Scoliosis
Zygapophyseal Joint
Full Text Links
  • NS
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2024 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr