Evaluation of the Electrically-Evoked Stapedial Reflex Threshold in Pediatric Cochlear Implant Users with High-Frequency Probe Tones

Abstract

Introduction Measurement of the electrically-evoked stapedial reflex threshold (ESRT) is an objective tool used to set the comfort levels in pediatric cochlear implant (PCI) users. The levels of ESRT have a strong correlation with comfort levels. However, the clinical utility of ESRT is limited because the ESRT response is not observed in all cochlear implant users. Objective To assess the effects of probe-tone frequency on ESRT and its relationship with the behavioral comfort levels in PCI users. Methods A total of 14 PCI users aged between 5 and 8 years participated in the study. The ESRT levels were measured using high-frequency probe tones (678 Hz and 1,000 Hz), and the default 226 Hz probe tone. The ESRT was measured with single-electrode stimulation across the three electrode locations (basal [E01]; middle [E11]; and apical [E22]). The ESRT levels measured with different probe tone frequencies were compared with the behavioral comfort levels. Results The mean ESRT levels using 1,000Hz and 678 Hz were lower than those measured using 226 Hz, but there was no main effect of probe-tone frequency (p > 0.05). A significantly high incidence of successful ESRT measurements occurred with higher-frequency probe tone (p < 0.039). Additionally, ESRT using higher probe tones significantly correlated with comfort levels. Conclusion The ESRT with higher probe tones was correlated with behavioral comfort levels and increased the success rate of the measurements. Higher-frequency probe tones may be useful whenever ESRT with 226 Hz is not measurable.

Patient and Device Factors Contributing to Electrically Evoked Stapedial Reflex Thresholds in Cochlear Implanted Adults

“…ESRT data were obtained using standard clinical techniques but did vary across participants with respect to recording parameters including laterality of immittance probe and probe frequency (226, 678, or 1,000 Hz). Generally, studies show only slight differences for ESRTs measured with different parameters, although it should be noted that small differences can exist [26][27][28]. Due to the study's retrospective design, these parameters could not be controlled and were often not recorded in clinical documentation.…”

Electric Auditory Brainstem Response Audiometry in Cochlear Implants: New Recording Paradigm

“…Despite the fact that electric compound action potentials (ECAP) and the electric stapedial muscle reflex (ESRT) have more clinical value, E-ABR is preferable in some situations, such as auditory neuropathy, cases with questionable integrity of the auditory pathway through the brainstem, or some cochlear malformations where the ECAP cannot be recorded. Although the ESRT is more correlated with MCL, it could not be recorded in all cases due to increased middle ear stiffness in the implanted ear as a result of CI surgery or middle ear disorders in the non-implanted side [ 8 ]. Owing to the great flexibility in the stimulation and recording paradigms, E-ABR can be used as a suitable measure of the threshold (T) levels in CI cases [ 9 , 10 , 11 ].…”