[1] Univ Hosp Birmingham, Neuroophthalmol, Birmingham, W Midlands, England
[2] Univ Birmingham, Metab Neurol, Birmingham, W Midlands, England
[3] Univ Birmingham, Birmingham Clin Trials Unit, Birmingham, W Midlands, England
[4] Univ Birmingham, Inst Metab & Syst Res, Birmingham, W Midlands, England
[5] Royal Hallamshire Hosp, Dept Neurol, Sheffield, S Yorkshire, England
[6] Univ Hosp Birmingham, Upper GI Unit, Birmingham, W Midlands, England
[7] Univ Hosp Birmingham, Minimally Invas Unit, Birmingham, W Midlands, England
[8] Univ Birmingham, Inst Appl Hlth Res, Birmingham, W Midlands, England
[9] Univ Birmingham, Inst Canc & Genom Sci, Birmingham, W Midlands, England