ABSTRACT
Obstructive sleep apnea syndrome [OSAS] is a common disorder characterized by recurrent apnea during sleep. Nocturnal laboratory-based polysomnography [PSG] is the gold standard test for diagnosis of OSA. The sufferers may complain from daytime sleepiness, snoring or occasional headaches. Serious consequences such as cardiovascular complications, stroke or symptoms of depression may complicate the syndrome. Headache prevalence due to sleep apnea is estimated 1%-2% in general population and affects 2%-8% of middle age population. Morning headache is more common in the OSAS patients. OSAS patients present with various characteristics of morning headache. Treatment with continuous positive airway pressure usually reduces headache. The pathophysiologic background for a relation between obstructive sleep apnea and morning headache is multifactorial. Some theories have been proposed for OSAS-related headaches such as changing oxygen saturation during sleep, cerebral vasodilation and increased intracranial pressure due to cerebral vasodilation, sleep disruption and depression but the definite cause of headaches in OSAS patients is not yet clear