[1] Semmelweis Univ, Dept Otolaryngol & Head & Neck Surg, Budapest, Hungary
[2] Manchester Univ NHS Fdn Trust, Wythenshawe Hosp, Manchester, Lancs, England
[3] Semmelweis Univ, Dept Pulmonol, Budapest, Hungary
[4] Gottsegen Gyorgy Hungarian Inst Cardiol, Budapest, Hungary
[5] Heim Pal Natl Paediat Inst, Sleep Lab & Sleep Surg Unit, Budapest, Hungary