1. Wake Forest School of Medicine; Winston-Salem NC USA
2. Laniado Hospital; Netanya Israel
3. Center for Headache and Pain; Cleveland Clinic Neurological Institute; Cleveland OH USA
4. Mayo Clinic Arizona; Phoenix AZ USA
5. Neurology; University of South Florida; Tampa FL USA
6. Brigham and Women's Hospital; Harvard Medical School; John R. Graham Headache Center; Boston MA USA