A mild cerebellar tonsillar ectopia is the result of the cerebellar tonsils slightly extending through the base of the skull, as stated by the Dallas Neurosurgical and Spine Department of the Presbyterian Hospital of Dallas. The cerebellar tonsils are located at the posterior part of the brain. Cerebellar tonsillar ectopia may be considered a mild form of a Chiari malformation, depending on the severity of visible symptoms.
Frequent symptoms that are associated with mild cerebellar tonsillar ectopia include headaches, pain around the neck area, problems balancing and unclear vision. Extending the head or neck often exacerbates these symptoms.
An MRI scan is required to detect malformations of the cerebellar tonsils. Afflicted individuals are treated with surgery to relieve pressure around the brain and spinal column.