1. Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London , London, WC1N 3BG , UK
2. Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery , London, WC1N 3BG , UK
3. Institute of Neurosciences, Cleveland Clinic London , London, SW1X 7HY , UK