[1] Univ Calif Los Angeles, Dept Neurol, Headache Res & Treatment Program, Los Angeles, CA 90024 USA
[2] Albert Einstein Coll Med, 2Dept Neurol, Bronx, NY 10467 USA
[3] Albert Einstein Coll Med, 2Dept Epidemiol, Bronx, NY 10467 USA
[4] Albert Einstein Coll Med, 2Dept Populat Hlth, Bronx, NY 10467 USA
[5] Albert Einstein Coll Med, Montefiore Headache Ctr, Bronx, NY 10467 USA
[6] Mayo Clin Arizona, Dept Neurol, Phoenix, AZ USA
[7] Thomas Jefferson Univ Hosp, Dept Neurol, Philadelphia, PA 19107 USA
[8] Thomas Jefferson Univ Hosp, Jefferson Headache Ctr, Philadelphia, PA 19107 USA
[9] Michigan Head Pain & Neurol Inst, Dept Neurol, Ann Arbor, MI USA
[10] Swedish Pain & Headache Ctr, Seattle, WA USA
[11] Univ Calif San Francisco, Dept Neurol, Headache Grp, San Francisco, CA USA
[12] Headache Res & Treatment Program, Dept Neurol, Los Angeles, CA USA