Associated Conditions & Findings
Chiari malformation
A Chiari malformation is a condition where lower parts of the brain extend toward or through the opening at the base of the skull.
In short: Chiari malformation
- Chiari III is specifically associated with a posterior encephalocele.
- Different types vary in severity.
- It involves the back-and-base of the brain.
- It is assessed with imaging.
What it is
It is a group of conditions in which lower brain structures (such as the cerebellum) extend toward or through the foramen magnum at the base of the skull. The types differ in their features and severity.
Understanding Chiari malformation
Among the types, Chiari III is specifically associated with a posterior (occipital or high cervical) encephalocele containing hindbrain tissue, while Chiari II is associated with spina bifida. Imaging examines the back-and-base of the brain to characterize the malformation, which informs the surgical plan for posterior encephaloceles.
Why it matters
Understanding Chiari malformation helps families see why posterior encephaloceles are examined for hindbrain involvement, and why the specific type (especially Chiari III) is part of the assessment.
Common questions
Which Chiari type involves an encephalocele?
Chiari III is associated with a posterior encephalocele.
Which type involves spina bifida?
Chiari II.
How is it assessed?
With imaging of the back-and-base of the brain.
Bottom line
A Chiari malformation involves lower brain structures extending toward the skull base, with Chiari III linked to posterior encephalocele.
Browse all 265 Encephalocele definitions
Read the Encephalocele patient guides
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