1. Division of Headache and Facial Pain, Department of Neurology and Neurological Sciences Stanford University School of Medicine Stanford California USA
2. Neurology University of California Los Angeles California USA
3. Information Sciences Institute University of Southern California Los Angeles California USA
4. Neurology The George Washington University School of Medicine and Health Sciences Washington District of Columbia USA
5. Neurology Barrow Neurological Institute Phoenix Arizona USA
6. Neurology University of California Davis Davis California USA