This study characterized sleep parameters and complaints in a large clinical sample of migraineurs and examined sleep complaints in relation to headache frequency and severity.
The relationship between headache and sleep has been documented at least anecdotally in medical literature for well over a century and clinical texts allude to the importance of sleep as a headache precipitant. A small number of empirical studies have emerged, but the precise nature and magnitude of the headache/sleep association and underlying mechanisms remain poorly understood.
In this investigation, 1283 migraineurs were drawn from 1480 consecutive headache sufferers presenting for evaluation to a tertiary headache clinic. Patients underwent a physical examination and structured interview assessing a variety of sleep, headache, and demographic variables. Migraine was diagnosed according the IHS criteria (1.1 to 1.6 diagnostic codes). Migraineurs were 84% female, with a mean age of 37.4 years. Groups were formed based on patient's average nocturnal sleep patterns, including short, normal, and long sleep groups, and were compared on headache variables.
Sleep complaints were common and associated with headache in a sizeable proportion of patients. Over half of migraineurs reported difficulty initiating and maintaining sleep at least occasionally. Many in this sample reported chronically shortened sleep patterns similar to that observed in persons with insomnia, with 38% of patients sleeping on average 6 hours per night. Migraines were triggered by sleep disturbance in 50% of patients. "Awakening headaches" or headaches awakening them from sleep were reported by 71% of patients. Interestingly, sleep was also a common palliative agent for headache; 85% of migraineurs indicated that they chose to sleep or rest because of headache and 75% were forced to sleep or rest because of headache. Patients with chronic migraine reported shorter nightly sleep times than those with episodic migraine, and were more likely to exhibit trouble falling asleep, staying asleep, sleep triggering headache, and choosing to sleep because of headache. Short sleepers (ie, average sleep period 6 hours) exhibited significantly more frequent and more severe headaches than individuals who slept longer and were more likely to exhibit morning headaches on awakening.
These data support earlier research and anecdotal observations of a substantial sleep/migraine relationship, and implicate sleep disturbance in specific headache patterns and severity. The short sleep group, who routinely slept 6 hours per night, exhibited the more severe headache patterns and more sleep-related headache. Sleep complaints occurred with greater frequency among chronic than episodic migraineurs. Future research may identify possible mediating factors such as primary sleep and mood disorders. Prospective studies are needed to determine if normalizing sleep times in the short sleeps would impact headache threshold.