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.
Chiari malformation is a congenital (i.e. present at birth) structural problem at the base of the skull that affects the brain and spinal cord. In fact it is not a malformation of the brain at all.More accurately, the lower portion of the skull, the portion known as the posterior fossa, is too small to accomodate the lower portion of the brain. As a result, a portion of the cerebellum called the tonsils is forced to protrude into the spinal column.ypes of Chiari Malformation (CM). Type I involves the extension of the cerebellar tonsils (the lower part of the cerebellum) into the foramen magnum.There are usually no other associated malformations of the brain. This is the only form of Chiari malformation to present in adult life.