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.
Symptoms. The most common symptom of Chiari malformation is a headache, which begins at the back of the head (neck) and radiates upward. The pain is often made worse or can be brought on by coughing, sneezing or straining. These activities are known as valsalva maneuvers.here are several different forms. The most common type is the Chiari I malformation (CM) which this article addresses. Less commonly, it may be known as Arnold-Chiari malformation, tonsillar herniation or tonsillar ectopia. Most cases of Chiari are congenital, meaning they are present from birth.