Botulinum toxin A in patients with oromandibular dystonia - Long-term follow-up

Objective: To study the safety and efficacy of botulinum toxin A (BTX) in p atients with oromandibular dystonia (OMD) and to compare the treatment resu lts of the various subtypes of OMD. Background: OMD is one of the most chal lenging forms of dystonia to treat. Pharmacologic therapies are generally n ot effective, and there are no surgical alternatives. Methods: Of 202 patie nts diagnosed clinically to have OMD in a movement disorders clinic over a period of 10 years, 162 patients satisfied the study inclusion criteria. Th e masseters and submentalis complex were the only two muscle groups injecte d with BTX in this group of patients. Results: The mean age was 57.9 +/- 15 .3 years and the mean follow-up period was 4.4 +/- 3.8 years. More than hal f the patients had jaw-closing (JC) dystonia. A total of 2,529 BTX treatmen ts were administered into the masseter muscles, submentalis complex, or bot h during a total of 1,213 treatment visits. The mean doses of BTX (per side ) were 54.2 +/- 15.2 U for the masseters and 28.6 +/- 16.7 U for the submen talis complex. The mean total duration of response was 16.4 +/- 7.1 weeks. The mean global effect of BTX was 3.1 +/- 1.0 (range, 0 to 4, where 4 equal s the complete abolition of the dystonia), with the JC dystonia patients re sponding best. Fifty-one patients (31.5%) reported adverse effects with BTX in at least one visit. Complications such as dysphagia and dysarthria were reported in 135 (11.1%) of all treatment visits. Conclusions: BTX is a saf e and effective long-term treatment for OMD. JC dystonia responds better th an jaw-opening or mixed dystonias, and the treatment of the latter types of OMD are more Likely associated with dysphagia and dysarthria. Jaw-opening dystonia can be treated successfully by injecting the submentalis complex.