Objective: To evaluate the feasibility of detecting stapedius reflex (SR) through direct middle ear pressure monitoring during contralateral acoustic stimulation. Study design: Prospective, observational, single-centre feasibility study. Setting: Tertiary referral centre; intraoperative setting during tympanotomy procedures. Patients: Eleven adult patients (≥18 y) with unilateral sudden sensorineural hearing loss undergoing transtympanic dexamethasone instillation, with an elicitable SR through contralateral stimulation, were included in this study. Patients with SR thresholds >100 dB HL were excluded. Intervention (s): A pressure transducer was inserted intraoperatively into the middle ear. A tympanometer device on the contralateral side apply acoustic stimulation and monitored the SR on that side. Stimulation was ECG-synchronized, and filtering was applied to the pressure signal to enhance detection. Main outcome measure(s): Detection of SR-related pressure changes using the pressure transducer, compared with tympanometry-based detection. Results: Out of 32 stimulus combinations, 24 elicited confirmed stapedius reflexes, while 8 did not. Among the 24 reflex-positive cases, the pressure-based method correctly identified reflex-related pressure changes in 20 instances, yielding a detection accuracy of 83.3% for confirmed reflexes. In the remaining 4 reflex-positive cases, the system failed to detect a response. In all 8 cases where no reflex was elicited, the system also did not detect any pressure changes, indicating no false positives. Conclusions: Middle ear pressure monitoring is a feasible method for detecting SR. This approach demonstrates feasibility under intraoperative conditions and may, with further development and validation, support future objective reflex assessment in cochlear implant users.
Luna et al. (Tue,) studied this question.