1. Department of Neurology, Royal North Shore Hospital, St Leonards, New South Wales, Australia
2. Northern Clinical School, University of Sydney, St Leonards, New South Wales, Australia
3. Department of Ophthalmology, Royal North Shore Hospital, St Leonards, New South Wales, Australia
4. Department of Haematology and Transfusion Medicine, Royal North Shore Hospital, St Leonards, New South Wales, Australia