Headache and sleep disorders are related in several ways. Sleep disorders occur in headache patients, headache is a common manifestation of sleep disorders, and secondary disorders may cause headache and sleep complaints. Excessive daytime sleepiness (EDS) or excessive somnolence is a common symptom, with a prevalence of 10–20% in the general population.¹

EDS is a subjective feeling of a compelling need for sleep at unusual times and in abnormal environmental conditions. Sleep deprivation, sleep fragmentation, and hypoxia are believed to be the main mechanisms leading to EDS. EDS increases the risk of car accidents, causes health status and quality of life to deteriorate, and may increase mortality. EDS is associated with obstructive sleep apnoea syndrome, brain tumours, epilepsy, stroke, degenerative diseases, trauma, multiple sclerosis, and neuromuscular disorders.¹ The prevalence, mechanisms, impact, diagnosis, and treatment of EDS have never been assessed in migraine patients.

We studied 200 consecutive patients with chronic or episodic migraine diagnosed according to the second edition of the International Headache Society diagnostic criteria for migraine² from the Jefferson Headache Center, Philadelphia, USA. The Epworth sleepiness scale (ESS)³ was applied to all patients and correlated with the diagnosis of chronic/episodic migraine, age, sex, body mass index (BMI), and headache …