The Effect of Test, Electrode, and Rate on Electrocochleography Measures

Abstract

Background:

Electrocochleography (ECochG) is the measurement of stimulus-related cochlear potentials and the compound action potential (AP). Its primary clinical application is with the assessment of inner ear disorders. There are few studies examining the variability of ECochG measures.

Purpose:

The objective of the study was to examine the effect of test (i.e., initial versus retest), electrode (i.e., extratympanic versus tympanic), and stimulus rate (i.e., 7.7 versus 77.7/sec) on ECochG indices (i.e., summating potential [SP] amplitude, AP latency, AP amplitude, SP/AP amplitude ratio, and SP/AP area ratio).

Research Design:

Correlational and three-factor repeated measures designs were employed.

Study Sample:

Eighteen normal-hearing young adults participated.

Data Collection and Analysis:

ECochG responses were obtained with 90 dB nHL click stimuli for an initial test and retest at two stimulus rates with a commercially available extratympanic (TIPtrode™) and tympanic (Lilly TM-Wick) electrode. Separate repeated measures linear mixed-model analysis of variance examined the effect of test, electrode, and rate for all ECochG indices. Test–retest variability was also examined with correlation analyses; an examination of mean test–retest differences and their 95% confidence intervals (CI); and construction of Bland-Altman plots.

Results:

The presence of SP and AP responses varied across experimental conditions. Electrode and rate were statistically significant predictors (p < 0.05) of SP and AP responses: SP and AP responses were more likely to be present with the tympanic electrode and at the slow rate. Statistically significant correlations (p < 0.05) were found between initial tests and retests with all ECochG indices with both electrodes with the exception of SP amplitude with the TIPtrode™ electrode. There were no significant main effects of test (initial versus retest) or interactions of test and electrode or rate for any of the ECochG indices (p > 0.05). The 95% CI of the mean test–retest differences contained 0 confirming that the effect of test was not statistically significant. There was a statistically significant main effect of electrode (p < 0.05) on three ECochG measures. The Lilly TM-Wick electrode produced larger SP amplitudes, AP amplitudes, and SP/AP area ratios than TIPtrode™ electrodes. A statistically significant main effect of rate (p < 0.05) was identified for all ECochG measures. The effect of rate on AP latency and amplitude was expected. Increasing the stimulus rate prolonged the AP latency and decreased AP amplitude. SP amplitude was larger for the faster rate.

Conclusions:

There was no difference between electrodes with regard to test–retest measures. However, considering the higher likelihood of ECochG SP and AP responses and larger SP amplitude, SP/AP amplitude ratio, and SP/AP area ratio indices, the tympanic electrode placement is recommended for clinical practice. The addition of a fast stimulus rate may be considered for enhanced SP amplitude, SP/AP amplitude ratio, and SP/AP area ratio albeit with the consideration of the loss of SP and AP responses in some individuals.

Key Words

action potential - electrocochleography - electrode - stimulus rate - summating potential - test–retest variability

This paper was presented at the 2016 American Speech-Language-Hearing Association Annual Convention, Philadelphia, PA. Alyson Butler Lake is currently associated with Blue Ridge Ear, Nose, Throat & Plastic Surgery, Lynchburg, VA.

• REFERENCES

• American National Standards Institute 2010. Specification for Audiometers. (ANSI S3.6-2010). New York, NY: ANSI;
• Bergholtz LM, Hooper RE, Mehta DC. 1976; Test-retest reliability in clinical electrocochleography. Ann Otol Rhinol Laryngol 85 (5 Pt.1) 679-685
• Bland JM, Altman DG. 1986; Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1 (8476) 307-310
• Bland JM, Altman DG. 1999; Measuring agreement in method comparison studies. Stat Methods Med Res 8 (02) 135-160
• Coats AC. 1981; The summating potential and Meniere’s disease. I. Summating potential amplitude in Meniere and non-Meniere ears. Arch Otolaryngol 107 (04) 199-208
• Densert B, Arlinger S, Sass K, Hergils L. 1994; Reproducibility of the electric response components in clinical electrocochleography. Audiology 33 (05) 254-263
• Durrant JD. 1986; Observations on combined noninvasive electrocochleography and auditory brainstem response recording. Semin Hear 7 (03) 289-304
• Eason S. 1991. Why generalizability theory yields better results than classical test theory: A primer with concrete examples. In: Thompson B. Advances in Educational Research: Substantive Findings, Methodological Developments. Vol. 1 Greenwich, CT: JAI Press; 83-98
• Ferraro JA. 2010; Electrocochleography: a review of recording approaches, clinical applications, and new findings in adults and children. J Am Acad Audiol 21 (03) 145-152
• Ferraro JA, Durrant JD. 2006; Electrocochleography in the evaluation of patients with Ménière’s disease/endolymphatic hydrops. J Am Acad Audiol 17 (01) 45-68
• Ferraro JA, Grasel S, Kileny P. 2017. Guidelines for ECochG recording and measurement protocols. Poster presented at the 2017 AudiologyNOW! Conference; Indianapolis, IA:
• Ferraro JA, Kileny P. 2016. Towards the standardization of ECochG recording and measurement protocols. Poster presented at the 2016 American Speech-Language-Hearing Convention; Philadelphia, PA:
• Ferraro JA, Krishnan G. 1997; Cochlear potentials in clinical audiology. Audiol Neurootol 2 (05) 241-256
• Ferraro JA, Thedinger BS, Mediavilla SJ, Blackwell WL. 1994; Human summating potential to tone bursts: observations on tympanic membrane versus promontory recordings in the same patients. J Am Acad Audiol 5 (01) 24-29
• Ferraro JA, Tibbils RP. 1999; SP/AP area ratio in the diagnosis of Ménière’s disease. Am J Audiol 8 (01) 21-28
• Gibson WPR, Moffat DA, Ramsden RT. 1977; Clinical electrocochleography in the diagnosis and management of Meneère’s disorder. Audiology 16 (05) 389-401
• Grasel SS, Beck RMO, Loureiro RSC, Rossi AC, de Almeida ER, Ferraro J. 2017; Normative data for TM electrocochleography measures. J Otol 12 (02) 68-73
• Gürkov R, Pyykö I, Zou J, Kentala E. 2016; What is Menière’s disease? A contemporary re-evaluation of endolymphatic hydrops. J Neurol 263 (Suppl 1) S71-S81
• Intelligent Hearing Systems. (n.d.). Electrocochleography using SmartEP. http://www.ihsys.com/SmartNotes/SNSEP030.pdf . Accessed August 14, 2017
• Marangos N. 1996; Hearing loss in multiple sclerosis: localization of the auditory pathway lesion according to electrocochleographic findings. J Laryngol Otol 110 (03) 252-257
• Margolis RH, Levine SC, Fournier EM, Hunter LL, Smith SL, Lilly DJ. 1992; Tympanic electrocochleography: normal and abnormal patterns of response. Audiology 31 (01) 8-24
• Margolis RH, Rieks D, Fournier EM, Levine SE. 1995; Tympanic electrocochleography for diagnosis of Menière’s disease. Arch Otolaryngol Head Neck Surg 121 (01) 44-55
• Mori N, Matsunaga T, Asai H. 1981; Intertest reliability in non-invasive electrocochleography. Audiology 20 (04) 290-299
• Oh KH, Kim KW, Chang J, Jun HS, Kwon EH, Choi JY, Im GJ, Chae SW, Jung HH, Choi J. 2014; Can we use electrocochleography as a clinical tool in the diagnosis of Meniere’s disease during the early symptomatic period?. Acta Otolaryngol 134 (08) 771-775
• Park DL, Ferraro JA. 1999; Intrasubject test-retest reliability in tympanic electrocochleography. J Am Acad Audiol 10: 160-165
• Roland PS, Rosenbloom J, Yellin W, Meyerhoff WL. 1993; Intrasubject test-retest variability in clinical electrocochleography. Laryngoscope 103 (09) 963-966
• Roup CM, Wiley TL, Safady SH, Stoppenbach DT. 1998; Tympanometric screening norms for adults. Am J Audiol 7 (02) 55-60
• Ruth RA, Lambert PR. 1989; Comparison of tympanic membrane to promontory electrode recordings of electrocochleographic responses in patients with Meniere's disease. Otolaryngol Head Neck Surg 100 (06) 546-552
• Stuart A, Yang EY, Stenstrom R. 1990; Effect of temporal area bone vibrator placement on auditory brain stem response in newborn infants. Ear Hear 11 (05) 363-369
• Wagenaar VA. 1969; Note on the construction of digram-balanced Latin squares. Psychol Bull 72 (06) 384-386
• Wilson WJ, Bowker CA. 2002; The effects of high stimulus rate on the electrocochleogram in normal-hearing subjects. Int J Audiol 41 (08) 509-517
• Wuyts FL, Van de Heyning PH, Van Spaendonck M, Van der Stappen A, D’Haese P, Erre J, Charlet de Sauvage R, Aran J. 2001; Rate influences on tone burst summating potential amplitude in electrocochleography: clinical(a) and experimental(b) data. Hear Res 152 1–2 1-9