1. Department of Medicine, Queen's Hospital, Barking, Havering and Redbridge University Hospitals NHS Trust, Romford, Essex, UK
2. Department of Neurosurgery, Essex Centre for Neurological Sciences, Queen's Hospital, Barking, Havering and Redbridge University Hospitals NHS Trust, Romford, Essex, UK
3. Department of Ear, Nose & Throat, Queen's Hospital, Barking, Havering and Redbridge University Hospitals NHS Trust, Romford, Essex, UK
4. Department of Medical Microbiology, Queen's Hospital, Barking, Havering and Redbridge University Hospitals NHS Trust, Romford, Essex, UK