When an individual has a structural abnormality that adversely causes an irregularity in the relationship between the brain tissues and skull, it is referred to as Chiari malformation. As a result of this structural abnormality, the brain tissues are pressed into the spinal canal inappropriately. Most cases of Chiari malformation are present at birth, while others occur during adulthood. Individuals affected by Chiari malformation may exhibit symptoms such as headache at the back of the head, dizziness, extremity numbness, extremity tingling, upper body weakness, upper body sensation loss, difficulty walking, neck pain, trouble swallowing, hearing loss, and balance trouble. Diagnosis of Chiari malformation is made by physical examination, x-rays, CT scans, and MRI scans. Treatment for Chiari malformation may include medication and surgery.
An individual who has Chiari malformation may also have genetic mutations that have caused them to develop this abnormality. The specific gene components that cause one individual to have Chiari malformation and not another are not known. However, the medical literature contains numerous reports and studies where Chiari malformations develop in more than one family member within different families. Genetic mutations that cause any sort of abnormal growth in an individual's skull that takes up extra space can cause them to develop Chiari malformation. Any diseases or conditions caused by genetic mutations that cause an individual to have or develop intracranial hypertension can also result in the presence of Chiari malformations. Chiari malformation can also be caused by a genetically precipitated condition or disease that has adverse effects on the shape, structure, and or development of the cervical portion of an individual's spine. Larger syndromes caused by genetic mutations, including Albright hereditary osteodystrophy, achondroplasia, hereditary connective tissue diseases, Goldenhar syndrome, Hajdu-Cheney syndrome, and Ehlers-Danlos syndrome can cause an individual to develop Chiari malformation.