Delineation of the Clinical Features and Treatment Response of Oromandibular Dystonia: A Multicenter Summary of 2,057 Cases

Objective To better characterize oromandibular dystonia (OMD) to facilitate early diagnosis and test the hypothesis that botulinum toxin treatment alleviates symptoms, regardless of etiology, to provide guidance on treatment strategies. Methods To better characterize this condition we utilize a three-pronged approach. First, we provide a comprehensive summary of the world’s literature encompassing 1157 cases in 27 separate manuscripts. Next, we describe the clinical features of 727 OMD subjects enrolled by the Dystonia Coalition (DC), an international multicenter database. Finally, we provide details of the treatment approach and response from two expert centers where large numbers of OMD patients are followed. Cases from expert centers were utilized to analyze whether response to botulinum toxin varied by etiology of OMD. Results In all cohorts, typical age at onset was in the 50s and approximately 70 % of cases were female. Although the literature OMD more commonly described as a focal dystonia, analysis of the DC database revealed it more commonly appears as part of a segmental dystonia. Expert center review of 173 cases revealed botulinum toxin injections improved symptom severity by more than 50% in approximately 78% of subjects. Among the patients at expert centers, analysis revealed that treatment response did not vary by etiology. Conclusions Botulinum toxin injections are an effective treatment for OMD, regardless of etiology. By providing a more comprehensive description of OMD and the therapeutic efficacy of botulinum toxin for this type of dystonia, we hope to improve clinical recognition to aid in timely diagnosis and inform treatment strategies.