Peter is a mischievous 12-year-old boy with an irrepressible rebellious streak, but in the bleak London orphanage where he has lived his whole life those qualities do not exactly fly....
Chiari malformation, also known as an Arnold-Chiari malformation, is a congenital (present at birth) defect occurring in the back of the head where the brain and spinal cord connect.There are four types of Chiari malformations:1  Type 1 â Occurring when the base of the skull and upper spinal area do not form properly, a type 1 Chiari malformation commonly goes unnoticed until problems arise in the adolescent or adult years of life.here are four types of Chiari malformations: 1  Type 1 â Occurring when the base of the skull and upper spinal area do not form properly, a type 1 Chiari malformation commonly goes unnoticed until problems arise in the adolescent or adult years of life.
Note that the ectopic cerebellar tonsils are positioned snugly in the posterolateral subarachnoid space of the cervical spinal canal. Chiari I malformation is not directly associated with other congenital brain malformations, specifically myelomeningocele, which is a feature of Chiari II malformation.ote that the ectopic cerebellar tonsils are positioned snugly in the posterolateral subarachnoid space of the cervical spinal canal. Chiari I malformation is not directly associated with other congenital brain malformations, specifically myelomeningocele, which is a feature of Chiari II malformation.