Midline intra- cranial cyst is:
A. Choroid plexus cyst
B. Dandy-Walker cyst
C. Unilateral hydrocephalus
D. Porencephalic cyst
A. Choroid plexus cyst
B. Dandy-Walker cyst
C. Unilateral hydrocephalus
D. Porencephalic cyst
Ans. B. Dandy walker cyst
• Midline posterior fossa cyst seen in
dandy walker syndrome
• With agenesis of cerebellar vermis.
• May be associated with hydrocephalus.
Arnold-Chiari malformations are congenital herniations of hindbrain structures into the spinal canal.
• In type I Arnold-Chiari malformation, the cerebellar tonsils herniate into the foramen magnum;
• In type II Arnold-Chiari malformation, parts of the hindbrain, cerebellar vermis, and fourth ventricle herniate into the foramen. This second type is commonly associated with meningomyeloceles.
• With agenesis of cerebellar vermis.
• May be associated with hydrocephalus.
Arnold-Chiari malformations are congenital herniations of hindbrain structures into the spinal canal.
• In type I Arnold-Chiari malformation, the cerebellar tonsils herniate into the foramen magnum;
• In type II Arnold-Chiari malformation, parts of the hindbrain, cerebellar vermis, and fourth ventricle herniate into the foramen. This second type is commonly associated with meningomyeloceles.
Other neonatal presentations associated
with Arnold-Chiari malformation include hydrocephalus because of cerebrospinal
fluid obstruction and
· brainstem dysfunction causing stridor
and poor swallowing.
Milder cases may present later in life
with spinal cord or cerebellar symptoms
