Prevalence, natural history and dynamic nature of chronic headache and medication overuse headache in Italy: The SPARTACUS study.

We present the first prevalence data on chronic headache and medication overuse headache in an unselected Italian population and a high rate of spontaneous remission. These data support the interpretation of medication overuse headache as a specific migraine-related disorder that may reflect chronic migraine's dynamic nature, the need for more specific medication overuse headache diagnostic criteria, and highlight the priority of targeted public health policies.