Highlights of the 11th Congress of the International Headache Society, held September 13-16, 2003, in Rome, Italy. Updating the headache classification system.

The International Headache Society held their 11th biennial congress in Rome, Italy, on September 13-16, 2003. The meeting featured the introduction of the second edition to the International Classification of Headache Disorders, the first update to the document since its presentation in 1988. This report discusses some of the different classifications of headache and their treatments as discussed at the congress.