Causes & Risk Factors
Chiari II malformation
Chiari II malformation is a condition associated with spina bifida in which hindbrain structures are displaced downward, commonly causing hydrocephalus.
In short: Chiari II malformation
- It is associated with spina bifida (myelomeningocele).
- Hindbrain structures are displaced downward toward the spinal canal.
- It is commonly associated with hydrocephalus.
- It is a frequent cause of hydrocephalus in children with spina bifida.
What it is
Chiari II malformation is a condition, almost always associated with spina bifida (specifically myelomeningocele), in which hindbrain structures (including parts of the cerebellum and brainstem) are displaced downward toward the spinal canal. It is more complex than Chiari I.
Understanding Chiari II malformation
The downward displacement of hindbrain structures in Chiari II can obstruct the normal flow and outlets of CSF, and the malformation is commonly accompanied by hydrocephalus. In fact, most children with spina bifida and Chiari II develop hydrocephalus requiring treatment, often a shunt. Because Chiari II, spina bifida, and hydrocephalus frequently occur together, children with spina bifida are evaluated and monitored for hydrocephalus as part of their care. Managing the hydrocephalus is an important component of their overall treatment.
Why it matters
Understanding Chiari II malformation helps families see why hydrocephalus is so common in children with spina bifida, and why these children are monitored and often treated for hydrocephalus as part of comprehensive care.
Common questions
What is Chiari II malformation associated with?
Spina bifida (myelomeningocele).
Does it cause hydrocephalus?
It is commonly associated with hydrocephalus.
How is it different from Chiari I?
Chiari II is more complex and tied to spina bifida.
Bottom line
Chiari II malformation, associated with spina bifida, displaces hindbrain structures downward and commonly causes hydrocephalus.
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