Electromyographical recording of the electrically elicited stapedius reflex via a bipolar hook electrode.

OBJECTIVE: To prove the feasibility of recording stapedius reflexes by bipolar electromyography intra-operatively during cochlea implant via a bipolar hook needle electrode. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. PATIENTS: Adults receiving a MED-EL cochlear implant. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURES: Stapedius reflex responses can be recorded by electromyography. RESULTS: A double hook electrode could be inserted into the muscle tissue via the natural opening of the pyramid process along with the stapedius tendon. In 7 out of 10 patients supplied with MED-EL CIs (PULSARCI100 or SONATATI100), electrically elicited stapedius reflex potentials were recorded after eliminating stimulation artifacts caused by electromagnetic fields during electrical stimulation by low pass filtering. CONCLUSION: Intraoperative stapedius reflex recording by bipolar electromyography via a hook electrode is feasible. Further research will show whether these signals may be used for establishing a self-adjusting speech processor.