Relationship between obstructive sleep apnea and morning headache

Obstructive sleep apnea syndrome (OSAS) is a common disorder in the general population. Several studies have suggested that headaches, particularly morning headaches, are more common in patients with OSAS than in normal subjects. This study investigates whether exist correlation between morning headache and polysomnographic sleep parameters. This is a cross sectional study of 150 consecutive patients with OSA who underwent sleep polysomnography. Patients were interviewed about their headache history. Insomnia and subjective sleepiness was assessed using the Insomnia Severity Index and Epworth Sleepiness Scale. Polysomnographic recordings were compared in patients with and without morning headache. Headache and non-headache patients did not differ in the Respiratory Disturbance Index, either in Mean nocturnal SaO2 or sleep efficiency (P>0.05). The headache patients were more likely to be female and spend a lower time in sleep. Insomnia was a common complaint in patients being evaluated for obstructive sleep apnea. No significant association emerged between the Excessive Daytime Sleepiness with headache (P>0.05). Thus, nocturnal hypoxia is less likely to explain the high headache prevalence among patients admitted for polysomnography.