1. Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
2. Beth Israel Deaconess Medical Center Comprehensive Headache Center, Boston, MA, USA
3. Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
4. Department of Clinical Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
5. Departments of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
6. Departments of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA