PHILADELPHIA – Insomnia and poor sleep habits may be the cause of the transformation from episodic to chronic migraine, Dr. Anne H. Calhoun said in a poster session at the annual meeting of the American Headache Society.
This hypothesis turns on its head the former paradigm, which was that pain causes medication overuse, which causes migraines to become chronic, which then leads to insomnia and sleep problems.
But insomnia and poor sleep habits may be the cause and not the result of migraine's transformation to chronic.
Based on this assumption, Dr. Calhoun, a neurologist at the University of North Carolina in Chapel Hill, conducted a study to see whether improving sleep habits might improve headaches in chronic migraine sufferers. “We found that when you improve sleep, headaches improve,” she said.
The study included 147 women with chronic migraine seen in an academic headache clinic. The women were given a comprehensive sleep interview and instructed in sleep habit modification. (See box.) They were given the interview and asked about adherence to each of five instructions on all subsequent visits. They recorded their headaches in standardized diaries, from which a headache index was calculated.
At baseline, the women averaged 23 headache days per 28-day recording period, with a mean headache index of 46.1. Of the 147 women, 72.8% met International Classification of Headache Disorders (ICDH-2) criteria for medication overuse headache, and 85% reported awakening tired. The researchers looked at how improvement on each of the five sleep habits–as well as an aggregate of sleep habit improvements–affected headache frequency and severity.
They found that the more detrimental sleep habits women were able to improve, the less frequent and severe their headaches were. For example: for the 28 women who improved on all five detrimental sleep habits, headache frequency was 23.4 on average pre-sleep improvement vs. 10.4 on average post improvement, for an overall improvement of 58.7%. The headache index in the same group improved by 68.5%.
In contrast, for the nine women who managed to improve on only one or none of the detrimental sleep habits, frequency improved by 23.9%, and headache index improved by 26.3%.
Of the 108 women who completed at least 2 visits, 60 women (56%) reverted to episodic migraine after a mean of 2.8 visits.
Further study is needed to see if sleep problems might be a primary factor in the etiology of chronic migraine, rather than a secondary symptom, Dr. Calhoun said in an interview with this newspaper.
“I'd like to see doctors addressing sleep issues as a primary factor in chronic migraine,” she said. “Questions about sleep should move up to the top of the list when we're treating these patients. Then, if we find that patients have poor sleep habits, we can counsel them on how to improve their sleep which may, in turn, have a big impact on their migraines.”
Sleep-Habit Modification For Patients
▸ Plan consistent and adequate time for nocturnal sleep period (8 hours for adults and 10 hours for adolescents).
▸ Eliminate TV, reading, and music in bed.
▸ Decrease sleep-onset latency. (Use visualization technique, and allow no caffeine within 8 hours of bedtime).
▸ Avoid nocturia. (Allow 4 hours between dinner and bedtime, and minimize fluids before bedtime.)
▸ Eliminate naps.