Relief of tension-type headache symptoms in subjects with temporomandibular disorders treated with botulinum toxin-A

Background.-Temporomandibular disorder (TMD) and chronic tension headaches clinically coexist in many individuals. Generally considered as separate pathological entities, they have been clinically treated by different means. Objective.-To determine the utility of treatment with botulinum toxin for patients with coexisting TMD and chronic tension type headache. Methods.-In this open-label study of 60 subjects with chronic TMD, 46 subjects also met the diagnostic criteria for chronic tension headache. All 60 subjects were treated with 150 units of botulinum toxin-A injected into the masticatory muscles, specifically 50 units into each masseter and 25 units into each temporalis muscle. Results.-Thirty-eight of 60 subjects (63%) reported a 50% improvement in their facial pain during the follow-up period. The subset of 46 subjects with chronic tension headache and TMD symptoms reported a 50% or greater improvement in headache pain as well. The number of headache free days also improved postinjection. Conclusion.-These results suggest that the masticatory muscles, specifically the temporalis, may be involved in the pathogenesis of this form of chronic tension headache found in association with TMD.