[Morning headaches in patients with obstructive sleep apnea syndrome: Pathogenesis, differential diagnosis, and treatment].

Sleep disorders are often associated with painful ones, especially in patients with chronic syndromes. Cephalgia occupies an important place among such algic forms as fibromyalgia, back pain, and abdominal and joint pain. Headaches and sleep disturbances may be independent, derived from a single pathogenetic factor, or their relationship may be bidirectional. This review focuses on the reciprocal relationship between headaches and sleep disorders; particular attention is paid to the morning headache variant associated with obstructive sleep apnea (OSA). Modern data on the anatomical structures and pathophysiological mechanisms common to disorders in the regulation of the sleep-wake cycle and the perception of pain impulses are presented. Possible pathogenetic processes and nuances of differential diagnosis of headaches associated with sleep apnea are discussed. Methods of treating headaches associated with sleep disorders, in particular OSA-associated cephalgia, are addressed. The effectiveness of therapy with constant positive airway pressure (CPAP therapy) and splint therapy for OSA has been shown for headaches associated with sleep apnea.