Headache in Chiari malformation: a distinct clinical entity?

A relatively common group of developmental anomalies of the posterior fossa and its contents make up the Chiari malformations. The most common of these anomalies are the Chiari malformations type I and type II. Many patients with these defects are asymptomatic, but many of them suffer from headaches. Although the prevalence of common primary headache disorders in patients with Chiari malformations is similar to that of the general population, a particular type of occipital headaches occurs more frequently in patients with a Chiari malformation. In the two patients described in the illustrative case presentations, the major complaint was headache. Both had Chiari malformation type I diagnosed. Chiari malformation should be considered in the differential diagnosis of patients who complain of exertional headache. Exertional headaches or worsening of pain during Valsalva's maneuver should prompt clinical suspicion of an underlying intracranial lesion and warrants further evaluation by appropriate neuroimaging studies.