Facial dyskinesia induced by auditory stimulation: A report of four cases

Introduction: The Vibroacoustic Disease (VAD) is an occupational pathology induced by long-term (>10 yr) exposure to large pressure amplitude (greater than or equal to 90 dB SPL) and low frequency (less than or equal to 500 H z) noise. During studies contributing to the characterization of VAD, abnor mal facial movements induced by repetitive auditory stimuli were observed i n one individual employed as an aeronautical mechanic. The goal of this stu dy was to investigate the existence of movement disorders triggered by audi tory stimuli in a group of VAD-diagnosed patients. Methods: Sixty VAD patie nts received auditory and median nerve stimulation. Simultaneously, EEG mon itoring was performed. Results: Abnormal myoclonus movements were triggered by auditory stimuli in four patients. EEC recordings were normal in all 60 patients. Stimulation of the median nerves did not trigger any abnormal mo vements. Conclusion: These data suggest that this facial dyskinesia has a s ubcortical origin.