Cerebellar ectopia refers to a brain condition where the lobes at the base of the cerebellum, the cerebellar tonsils, push through the foramen magnum, at the base of the skull.
The foramen magnum accommodates the base of the brain stem and spinal cord, and when the cerebellar tonsils herniate through this opening, the patient can experience medical complications.
The process is congenital in nature.
Clinically and is progressive over the patient’s lifetime as the brain grows and shifts inside the skull.
Severe herniation is known as a Chiari malformation.
Cerebellar ectopia involves lesser protrusions.
Symptoms may not begin till adulthood.
In mild cases it may not be apparent until adolescence or adulthood.
Some patients present with symptoms in infancy.
Cerebellar ectopia may be associated with balance problems, headaches, blurred vision, and giddiness.
Symptoms may progress over time die to increased pressure.
CT or MRI of the brain can show the position of the cerebellum and may reveal the protrusion of the cerebellar tonsils through the foramen magnum.
Management includes observation or surgical decompression.