1. Headache and Facial Pain Group, University College London (UCL) Queen Square Institute of Neurology, London, UK
2. The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
3. Department of Neurology, Alfred Health, Melbourne, Australia
4. Department of Neuroscience, Monash University, Melbourne, Australia
5. Department of Neurology, Austin Health, Melbourne, Australia