[1] Queen Elizabeth Univ Hosp, Inst Neurol Sci, Dept Neurol, Glasgow G51 4TF, Lanark, Scotland
[2] Queen Elizabeth Univ Hosp, Dept Med, Glasgow G51 4TF, Lanark, Scotland
[3] SOLAS Fdn, 211 New City Rd, Glasgow G4 9PA, Lanark, Scotland
[4] Univ Glasgow, Sch Med, Wolfson Med Sch Bldg, Glasgow G12 8QQ, Lanark, Scotland