Botulinum toxin in tension-type headache.

Despite the controversy regarding specific mechanism of botulinum toxin action in pain relief, clinical results suggest that botulinum toxin type A may be promising treatment options for patients with primary chronic headache. To investigate this, we included sixteen patients with chronic tension-type headache in a prospective double blind, placebo-controlled crossover study and thirty patients in an open-label long-term study. All of the patients showed reduced severity of headache, reduced pericranial muscle tenderness and increased headache-free days during botulinum toxin A treatment. Moreover, constant and cumulative trend of improvement was present during long-term study indicating better quality of life during botulinum toxin treatment. There is need for further placebo-controlled clinical studies to identify the optimal dose, optimal number and place of injection sites as well as optimal injection techniques.