[1] MANCHESTER ROYAL INFIRM, DEPT OTOLARYNGOL, MANCHESTER M13 9WL, LANCS, ENGLAND
[2] CHURCHILL HOSP, DEPT MED GENET, OXFORD OX3 7LJ, ENGLAND
[3] MANCHESTER ROYAL INFIRM, DEPT NEUROSURG, MANCHESTER M13 9WL, LANCS, ENGLAND
[4] LONDON HOSP, DEPT NEUROSURG, LONDON E1 1BB, ENGLAND