1. Pain Research Institute; Clinical Sciences Centre; University Hospital Aintree; Liverpool; UK
2. Department of Anaesthesia; Leighton Hospital; Crewe; UK
3. Rehabilitation & Assessment Directorate; Acute Services; NHS Greater Glasgow & Clyde; UK
4. Department of Neurosurgery; University Hospital of Wales; Cardiff; UK
5. School of Natural Sciences & Psychology; Liverpool John Moores University; UK
6. Pain Research Institute; Institute of Translational Medicine; University of Liverpool; UK