Arnold-Chiari, or Arnold’s Syndrome, is a condition where the cerebellar tonsils pass through the base of the skull. If the tissue blocks outflow of cerebrospinal fluid, hydrocephalus can result. The condition can cause pains in the head, tiredness, weakness of muscles in face and head, dizziness, impaired coordination and possibly paralysis.
Arnold’s Syndrome can be diagnosed with magnetic resonance imaging and neurological exam. Herniation of the cerebellar tonsils will show in the MRI scan. In some cases, ultrasound can diagnose Arnold’s Syndrome during a prenatal examination.
Treatment of Arnold’s Syndrome involves decompression surgery. During surgery, specialists will work to relieve pressure by removing one or more cervical vertebrae. A shunt may also be placed to drain cerebrospinal fluid.
Arnold’s Syndrome is typed with Type 1 being the least severe and Type 4 being the most severe. Patients with Type 1 and Type 2 can be treated. Type 3 and Type 4 are often fatal.