Chiari Malformation Type 2
Type of disease: Rare conditions
Chiari malformation type 2 (CM type II) is a type of Chiari malformation in which both the cerebellum and brain stem tissue extend into the foramen magnum (the hole at the skull base for passing of the spinal cord). This form is often accompanied by a type of spina bifida called myelomeningocele, and can also be accompanied by syringomyelia, hydrocephalus, or other abnormalities. Symptoms in infants may include stridor (wheezing sound); difficulty swallowing (dysphagia); feeding difficulties; hypotonia; and weak cry. Symptoms in children and/or adults may include headache; fatigue; loss of vision; tingling extremities; nausea; dysphagia; dizziness; muscle weakness; and ataxia. Adults and adolescents who previously had no symptoms may begin to have symptoms later in life. The exact cause of the condition is not known but it appears to be due to a developmental failure of the brain stem and upper spine. The term Arnold-Chiari malformation is technically specific to type II but may sometimes be used to describe other types of Chiari malformations.
Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.