1. West London Neurosciences Centre, Charing Cross Hospital, Fulham Palace Road, London, UK
2. Department of Neurology, Wessex Neurological Centre, Southampton General Hospital, Tremona Road, Southampton, SO9 4XY, UK
3. Department of Neuroradiology, Wessex Neurological Centre, Southampton General Hospital, Tremona Road, Southampton, SO9 4XY, UK