1. Jefferson Headache Center, Philadelphia, PA
2. Spaulding Rehabilitation Hospital, Boston, MA
3. Diamond Headache Clinic, Chicago, IL
4. Vedanta Research, Chapel Hill, NC
5. Department of Neurology
6. The Montefiore Headache Center, Bronx, NY
7. The New England Center for Headache, Stamford, CT, USA
8. Department of Epidemiology and Population Health, Albert Einstein College of Medicine