Chiari malformation denotes a pathological caudal ectopy of the cerebellar tonsils below the level of the foramen magnum. Several types of the condition exist, of which Type 1 is the most common. It often results in few if any symptoms, and in many cases is detected as an incidental finding when an MRI is performed. Symptoms such as headache, dizziness or nausea may be related to narrowing of the foramen magnum due to blocked circulation of spinal fluid. Surgical treatment must be considered in symptomatic cases.