Sleep-related headache syndromes.

An association between headache and sleep is long recognized in the medical literature and deemed highly clinically relevant for at least a portion of headache sufferers. Sleep-related headaches are not well understood, but recent advances in the neurophysiology of sleep and headache shed light on common biological processes potentiating their association. Respective diagnostic nosologies for headache and sleep disorders offer limited guidance but are evolving to better represent the known associations. A rational approach based on the available empiricism can assist the clinician in the assessment and treatment of headache. Each headache evaluation should include at least a brief sleep history. Headaches that occur during or after sleep, so called morning headache, may be secondary to a sleep disorder and call for a specific treatment. This case is best established for sleep-related breathing disorders, and treatment of apnea often leads to resolution of the headache. Although pure sleep-related headaches, such as hypoxemia-related headache and hypnic headache, are less prevalent and more easily recognized, primary headaches are often impacted to some degree by sleep. Additionally, common headache medications and comorbid conditions alter sleep architecture. Management of primary headache may be facilitated by attention to sleep complaints.