[1] Univ Duisburg Essen, Migraine & Headache Clin, Konigstein, Germany
[2] Univ Hosp Essen, Dept Neurol, Essen, Germany
[3] Walton Ctr Neurol & Neurosurg, Dept Neurol, Liverpool, Merseyside, England
[4] Univ Munich, Dept Neurol, D-80539 Munich, Germany
[5] Univ Liege, Dept Neurol, Liege, Belgium
[6] Charite, Berlin NeuroImaging Ctr, Berlin, Germany
[7] ElectroCore Med, Clin Affairs, Gothenburg, Sweden
[8] ElectroCore LLC, Sci Med & Clin Affairs, Basking Ridge, NJ USA