to the best of our knowledge, this study is the first to compare the sensitivity of the ICHD-3 beta criteria for " sleep apnoea headache " in OSAS patiens with morning headaches. In our study, we assessed headaches upon awakening in the morning but not headaches upon awakening during sleep or after a nap because the ICHD-3 beta criteria clearly state that a sleep apnoea headache is a morning headache caused by sleep apnoea.
This study demonstrated that 60.4 % and 81.3 % of patients with morning headache met the criteria for “sleep apnoea headache “established by ICHD-2 and ICHD-3 beta, respectively (Tables 1 and 2). The increased frequency of individuals who qualified for diagnosis was likely attributable to the extension of headache duration from 30 min to 4 h. This modification had clinical significance, as demonstrated in this study. Out of all morning headaches (n=48), 81.3 % (n=39) responded to CPAP therapy, and 19.7 % (n=10) of the CPAP treatable morning headaches did not fulfil the ICHD-2