CHRONIC TENSION-TYPE HEADACHE - AMITRIPTYLINE REDUCES CLINICAL HEADACHE-DURATION AND EXPERIMENTAL PAIN SENSITIVITY BUT DOES NOT ALTER PERICRANIAL MUSCLE-ACTIVITY READINGS

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 neurophysiolo gicaI 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 many of them had fail ed attempts at treatment. In the amitriptyline group, a significant re duction in daily headache duration was already found in the 3rd week o f treatment, while in the placebo group no significant changes in head ache duration were to be seen. In week 6 the amitriptyline group had a significantly shorter daily duration of headache than did the placebo group. Treatment did not result in any significant effects on EMG rec ordings of pericranial muscle activity either during relaxation or con traction, on exteroceptive suppression of the temporal muscle and on C NV. The sensitivity to suprathreshold experimental pain, however, was significantly reduced. The data show a statistically relevant reductio n of daily headache duration. However, they also show that amitriptyli ne can only partly alleviate chronic headaches but cannot cure them.