Cerebellar tonsillar hernia with syringomyelia is what disease

Syringomyelia is caused by a developmental abnormality associated with the foramen magnum. A foramen magnum abnormality causes some brain tissue to pass from the foramen magnum into the spinal canal where the spinal cord is located, resulting in a cerebellar subtonsillar hernia. A cerebellar subtonsillar hernia causes changes in intracranial pressure, resulting in local nerve compression, resulting in syringomyelia.