What is the primary cause of hydrocephalus in most children with spina bifida?

What is the primary cause of hydrocephalus in most children with spina bifida?

• A. Chiari II malformation
• B. Overproduction of CSF
• C. Obstruction in the normal flow of CSF
• D. Absorption failure of CSF

Answer: (A)

In spina bifida, hydrocephalus is most often caused by Chiari II malformation, where downward displacement of the hindbrain through the foramen magnum and crowding near the cerebral aqueduct blocks the normal CSF flow. This obstruction prevents cerebrospinal fluid from circulating properly, leading to enlarged ventricles and hydrocephalus. The problem isn’t excessive CSF production or a failure of absorption; it’s the hindbrain herniation that physically disrupts the CSF pathways. Chiari II malformation is the common structural issue tied to myelomeningocele, which is why it’s the primary driver of hydrocephalus in these children.

In spina bifida, hydrocephalus is most often caused by Chiari II malformation, where downward displacement of the hindbrain through the foramen magnum and crowding near the cerebral aqueduct blocks the normal CSF flow. This obstruction prevents cerebrospinal fluid from circulating properly, leading to enlarged ventricles and hydrocephalus. The problem isn’t excessive CSF production or a failure of absorption; it’s the hindbrain herniation that physically disrupts the CSF pathways. Chiari II malformation is the common structural issue tied to myelomeningocele, which is why it’s the primary driver of hydrocephalus in these children.