Middle Ear Myoclonus: A Treatable Cause of Objective Tinnitus

Abstract

Objective: 1) Describe the presentation of an underdiagnosed cause of objective tinnitus. 2) Review the current literature and present an algorithm on diagnosis and management of middle ear myoclonus. 3) Use video to demonstrate surgical ablation of the stapedial and tensor tympani tendons to alleviate middle ear myoclonus. Method: This retrospective study analyzes the presentation and management of 6 patients diagnosed with middle ear myoclonus from 2009 to 2011. A review of the literature revealed 15 additional cases of middle ear myoclonus. An algorithm for the diagnosis and management of these patients is presented. Results: We report on the diagnostic findings of 6 patients identified at a tertiary care military medical center with middle ear myoclonus. Four of the 6 patients had a significant history of loud, explosive noise exposure during military deployments. Patients were diagnosed based on history, examination findings, and standard audiometry testing using a nonstimulated, spontaneous acoustic reflex decay tracing. Fifteen additional reported cases of either stapedial or tensor tympani myoclonus were identified in the English language literature. Observation, medications, botulinum toxin, and surgical sectioning of the stapedius and/or tensor tympani are recognized treatments of this disorder. Conclusion: Middle ear myoclonus is an underdiagnosed cause of objective tinnitus likely due to lack of familiarity with diagnostic findings. For symptomatic myoclonus, middle ear exploration with transection of the stapedius tendon, tensor tympani tendon, or both demonstrated the best outcomes, with 100% of patients achieving complete relief of tinnitus.