Headache and Chiari malformation

Chiari malformation is a rare medical condition that is characterized by downward displacement of the cerebellar tonsils through the foramen magnum. The clinical presentation of Chiari malformation is diverse, but headache is the most often reported symptom. The typical Chiari malformation headache is localized in the occipital part of the head and aggravated by coughing, other Valsalva manoeuvres, or physical exertion. The prevalence of other episodic primary headache disorders such as tension-type headache and migraine is not increased in patients with Chiari malformation. The underlying pathophysiology of headache in Chiari malformation is still enigmatic, but alteration of intrathecal pressure was suggested to be involved. Controlled treatment trials for CM-related headaches are not available and treatment recommendations are mainly based on case reports, small case series and clinical experience. Therefore, no firm recommendation regarding surgical treatment can be made.