Published online by Cambridge University Press: 12 March 2013
We report a previously undescribed association between transitory stapedial myoclonus, objective tinnitus and benign fasciculation syndrome.
Case report and review of the world literature regarding stapedial myoclonus.
A 30-year-old man with a diagnosis of benign fasciculation syndrome abruptly developed severe, low-pitched tinnitus on the right side. Otoscopic examination revealed rhythmic movement of the tympanic membrane, which was synchronous with the tinnitus. No palatal spasm was noted on nasopharyngeal examination. Brain magnetic resonance imaging and pure tone audiometry were unremarkable. Based on these findings, a diagnosis of objective tinnitus due to stapedial myoclonus was made. The objective tinnitus spontaneously disappeared within 48 hours of its appearance, but in the following days the patient suffered frequent, brief episodes of objective tinnitus lasting only a few seconds.
The occurrence of stapedial myoclonus in this patient indicated the presence of an underlying motor unit hyper-excitability. This case suggests that, in some patients, stapedial myoclonus may represent the clinical expression of diffuse motor unit hyper-excitability.