Hypnic headache: Another indomethacin-responsive headache syndrome?

Hypnic headache syndrome is a benign, recurrent, late-onset headache disord er that occurs exclusively during sleep. Lithium has been reported to be an effective treatment, but the side effects of this medication are sometimes prohibitive, particularly in the elderly. Other drugs have been reported t o be effective in this disorder, including caffeine, flunarizine, and verap amil. Recently, indomethacin has been reported to effectively suppress hypn ic headaches. We report the response of seven patients with hypnic headache who were treated with indomethacin, Hypnic headache syndrome appears to re present yet another headache disorder in which there is sometimes an impres sive response to indomethacin.