Arnold-Chiari malformation- type 3




An extremely rare malformation where the base of the brain enters into the upper spinal canal. Type 3 involves the herniation of brain or brain stem tissue out of the back of the neck or head. The condition generally has a poor prognosis.


In one of the most severe types of the condition, Chiari malformation type III, a portion of the lower back part of the brain (cerebellum) or the brainstem extends through an abnormal opening in the back of the skull. This form of Chiari malformation is diagnosed at birth or by an ultrasound during pregnancy. This type of Chiari malformation has a higher mortality rate and may also cause neurological problems.

Known symptoms:

  • Weakness
  • Fatigue
  • Stiffness
  • Loss of ability to feel cold
  • Loss of ability to feel heat
  • Torticollis
  • Opisthotonus
  • Headache
  • Vertigo
  • Vocal cord paralysis
  • Apnea
  • Nystagmus
  • Swallowing difficulties
  • Ataxia
  • Dysphagia
  • Hydrocephalus
  • Encephalocele
  • Severe neurological defects
  • Abundant neurological deficits


  • Magnetic resonance imaging (MRI)
  • Computerized tomography (CT) scan


  • Mayo Clinic