[1] Albert Einstein College of Medicine,Pain Medicine, Palliative Care, Neurology
[2] Beth Israel Medical Center,Danish Headache Center, Neurology
[3] University of Copenhagen,Neurology, Albert Einstein College of Medicine
[4] Glostrup Hospital,Pain Medicine and Palliative Care
[5] National Board of Health,undefined
[6] Montefiore Headache Center,undefined
[7] Albert Einstein College of Medicine,undefined
[8] Beth Israel Medical Center,undefined