1. Department of Neurology, Santa Maria della Misericordia University-Hospital, Udine, Italy.
2. Department of Neurosurgery, Santa Maria della Misericordia University-Hospital, Udine, Italy.
3. Institute of Hygiene and Epidemiology, Santa Maria della Misericordia University-Hospital, Udine, Italy.
4. Headache Centre, Department of Neurosciences, Padua University, Padua, Italy.