Botulinum toxin (DYSPORT) in tension-type headaches.

OBJECTIVES: Botulinum toxin type A is effective in the reduction of muscle tenderness and pain in many diseases associated with myofascial pain. Since increased muscle tension may contribute to tension-type headaches, injections of botulinum toxin could be of therapeutic value.

METHODS/PATIENTS: Results of own investigations are presented, in particular a double-blind, placebo-controlled study with 21 patients fulfilling the International Headache Society criteria for tension-type hedaches. Participants were randomly assigned to verum (pericranial injection of 10 x 20 MU DYSPORT) or placebo condition (injection of isotonic saline in the same manner).

RESULTS: After 4, 8, and 12 weeks no significant differences between placebo and verum could be observed. Nevertheless, both groups significantly improved.

DISCUSSION: The findings strongly suggest that higher doses or other injection sites might be necessary to achieve therapeutic effects of botulinum toxin in tension-type headaches. Actually, we are participating in a multi-center study using 500 MU of DYSPORT. Besides dose-finding problems, another explanation could be that peripheral mechanisms--such as increased pericranial muscle tension--only play a minor role in the pathogenesis of tension-type headaches.