Continuous chronic tension-type headache unaffected by two hours of frontalis and trapezius relaxation

Fourteen patients with the continuous form of chronic tension-type headache maintained electromyographically documented relaxation of frontalis and trapezius muscles for two consecutive hours. The headache intensity of the group did not decrease from the beginning to the end of the recording session. This result is evidence against tonic muscle tension as the mechanism of this form of headache.