In a double-blind, placebo-controlled trial, the effect of 75 mg of a
slow-release formulation of
amitriptyline on the clinical severity of chronic
tension-type headache and on
headache-associated neurophysiological parameters (EMG activity, exteroceptive suppression of temporal muscle activity, contingent negative variation (CNV) and experimental
pain sensitivity) was investigated. All of the patients treated had a history of
headaches of many years standing, and numerous failed attempts at treatment. In the
amitriptyline group, a significant reduction in daily
headache duration was already found in the third week of treatment, while in the placebo group no significant changes in
headache duration were to be seen. In week 6 the
amitriptyline group had a significantly shorter daily duration of
headache than the placebo group. Treatment did not result in any significant effects on EMG recording of pericranial muscle activity either during relaxation or contraction, on exteroceptive suppression of the temporal muscle and on CNV. The sensitivity to suprathreshold experimental
pain, however, was significantly reduced. The data show a statistically relevant reduction of daily
headache duration in chronic
tension-type headache. However, they also show that
amitriptyline can only partly alleviate
chronic headaches but cannot cure them.