1 National Institute for Health Research University College London Hospitals Biomedical Research Centre, Box 29, UCL Institute of Neurology, London WC1N 3BG, UK; Epilepsy Society, Chalfont St Peter, UK.
2 National Institute for Health Research University College London Hospitals Biomedical Research Centre, Box 29, UCL Institute of Neurology, London WC1N 3BG, UK; Epilepsy Society, Chalfont St Peter, UK; Stichting Epilepsie Instellingen Nederland, Heemstede, Netherlands. Electronic address: l.sander@ucl.ac.uk.