Chiari malformations (types I-IV) are a group of congenital brain abnormalities affecting the structural relationships between the cerebellum, brainstem, the upper cervical cord, and the bony cranial base. Chiari malformation type II, also called classic CM, is the most common pediatric form, almost invariably associated with myelomeningocele that presents at birth. Myelomeningocele can be associated with partial or complete paralysis below the spinal opening, including lack of bladder and bowel control. The symptoms of CM type II may include: changes in breathing pattern, swallowing problems, such as gagging, quick downward eye movements, and weakness in arms.
Chiari malformation type II is usually diagnosed by ultrasound during pregnancy. It may also be diagnosed after birth or in early infancy. Infants and children with myelomeningocele may require surgery to reposition the spinal cord and close the opening at the back.
Alorainy (2006) reviewed and analyzed the MRI studies on 808 pediatric patients (aged 3 days to 15 years) over a 3-year period. There were 44 girls and 42 boys. A total of 114 congenital cerebral malformations were identified in 86 of these patients. A total of 12 patients were diagnosed with Chiari type II malformation. All patients with Chiari II were imaged after repair of myelomeningocele and at an age older than 1 year.