[1] Geisel Sch Med Dartmouth, Hanover, NH USA
[2] Albert Einstein Coll Med, Dept Neurol, Bronx, NY USA
[3] Charlie Univ Med Berlin, Dept Neurol, Berlin, Germany
[4] Thomas Jefferson Univ, Jefferson Headache Ctr, Philadelphia, PA USA
[5] Sutter Hlth, Walnut Creek, CA USA
[6] Amgen Inc, Global Biostat Sci, Thousand Oaks, CA USA
[7] Amgen Inc, Global Hlth Econ, Thousand Oaks, CA USA
[8] Amgen Inc, Global Dev, Thousand Oaks, CA USA