Clinical application of a multimodal electrophysiological test battery to predict optimal behavioral levels in cochlear implantees
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Department of Implant Otology, Madras ENT Research Foundation, Chennai, India
Department of Otolaryngology, H & N Surgery, Sri Ramachandra University, Chennai, India
Department of Audiology, Mandke Hearing Services, Pune, India
Publication date: 2013-12-31
Corresponding author
Raghunandhan Sampathkumar   

Raghunandhan Sampathkumar, Department of Implant Otology, Madras ENT Research Foundation, Chennai, India, e-mail: raghunandhansampath@gmail.com
J Hear Sci 2013;3(4):31-48
Indications for cochlear implantation have expanded to include very young children and those with syndromes or multiple handicaps. In such cases programming the implant based on behavioral responses may be tedious, wherein matching effective and appropriate measurable auditory percepts (maps) and becomes the key issue in the rehabilitation program. In ‘difficult to map’ scenarios, objective measures become paramount for predicting optimal current levels to be set in the map. We aimed (a) to study the trends in multi-modal electrophysiological tests and behavioral responses sequentially over the first year of implant use, (b) to generate normative data from the above, (c) to correlate the multi-modal electrophysiological thresholds levels with behavioral comfort levels, and (d) to create predictive formulas for deriving optimal comfort levels (if unknown), using linear and multiple regression analysis.

Materials and Methods:
This prospective study included 10 profoundly hearing impaired children aged 2 to 7 years with normal inner ear anatomy and no additional handicaps. They received the Advanced Bionics HiRes 90K implant with Harmony speech processor and used the HiRes-P with Fidelity 120 strategy. They underwent impedance telemetry, neural response imaging, electrically evoked stapedial response telemetry, and electrically evoked auditory brainstem response tests at 1, 4, 8, and 12 months of implant use, in conjunction with behavioral mapping. Trends in electrophysiological and behavioral responses were analysed using paired t-tests. Using Pearson’s correlation method, electrode-wise correlations were derived for NRI thresholds versus M-levels, and offset-based (apical, mid-array, and basal array) correlations for EABR and ESRT thresholds versus M-Levels were calculated over time. These were used to derive predictive formulae by linear and multiple regression analysis. Such statistically predicted M-levels were compared with the behaviorally recorded M-levels among the cohort, using Cronbach’s alpha reliability test method for confirming the efficacy of this method.

NRI, ESRT, and EABR thresholds showed statistically significant positive correlations with behavioral M-levels, which improved with implant use over time. These correlations were used to derive predicted M-levels using regression analysis. Such predicted M-levels were found to be close to the actual behavioral M-levels recorded among this cohort and proved to be statistically reliable.

The study has explored the trends and correlations between electrophysiological tests and behavioral responses, recorded over time among a cohort of cochlear implantees. It provides a statistical method which may be used as a guideline to predict optimal behavioral levels in difficult situations among future implantees. In ‘difficult to map’ scenarios, the best outcomes will come from following a protocol of sequential behavioral programming in conjunction with electrophysiological correlates.

Spivak LG, Chute PM. The relationship between electrical acoustic reflex thresholds and behavioral comfort levels in children and adult cochlear implant patients. Ear Hear, 1994; 15(2): 184–92.
Hodges AV, Butts SL, King JE. Electrically evoked stapedial reflexes -: utility in cochlear implant patients. In: Cochlear Implants: Objective Measures. 1st Edn; Whurr Publishers, (London, Philadelphia), 2003; S: 81–93.
Davids T, Valero J, Papsin BC, Harrison RV, Gordon KA. Effects of stimulus manipulation on electrophysiological responses of pediatric cochlear implant users. Part I: Duration effects and Part II: Rate effects. Hearing Research, 2008; 244: 7–24.
Mason S. Electrophysiologic and objective monitoring of the cochlear implant during surgery: implementation, audit and outcomes. Int J Audiol, 2004; 43: S33–38.
Abbas PJ, Hughes, ML, Brown CJ, Luk B, Wolaver A, Gervais J. The relationship between EAP & EABR thresholds and levels used to program the Nucleus 24 speech processor: Data from adults. Ear and Hearing, 2000; 21: 151–63.
Brown, Carolyn J. Clinical uses of electrically evoked auditory nerve and brainstem responses. Curr Opin Otolaryngol Head Neck Surg, 2003; 11(5): 383–87.
Gordon KA, Papsin BC, Harrison RV. Toward a battery of behavioral and objective measures to achieve optimal cochlear implant stimulation levels in children. Ear Hear, 2004; 25: 447–63.
Shallop JK, Ash KR. Relationships among comfort levels determined by cochlear implant patient’s self-programming, audiologist’s programming, and electrical stapedius reflex thresholds. Ann Otol Rhinol Laryngol Suppl, 1995; 166: 175–76.
Thai-Van H, Chanal JM, Coudert C, Veuillet E, Truy E, Collet L. Relationship between NRT measurements and behavioral levels in children with the Nucleus 24 cochlear implant may change over time: preliminary report. Int J Pediatr Otorhinolaryngol, 2001; 58: 153–62.
Smoorenburg GF, Willeboer C, Van Dijk JE. Speech perception in Nucleus CI24M cochlear implant users with processor settings based on electrically evoked compound action potential thresholds. Audiol Neurootol, 2002; 7: 335–47.
Di Nardo W, Ippolito SW, Quaranta N, Cadoni G, Galli J. Correlation between NRT measurement and behavioural levels in patients with the Nucleus 24 cochlear implant. Acta Otolaryngol Italica, 2003; 23: 352–55.
Han DM, Chen XQ, Zhao XT, Kong Y, Li YX, Liu S et al. Comparisons between Neural Response Imaging thresholds; electrically evoked auditory reflex thresholds and most comfortable loudness levels in CII Bionic Ear users with HiRes sound processing strategies. Acta Otolaryngo, 2005; 125(7): 732–35.
Caner G, Olgun L, Gültekin G, Balaban M. Optimizing Fitting in Children Using Objective Measures Such as Neural Response Imaging and Electrically Evoked Stapedius Reflex Threshold. Otol Neurotol, 2007; 28(5): 637–40.
Hughes ML, Vander Werff KR, Brown CJ, Abbas PJ, Kelsay DM, Teagle HF et al. A longitudinal study of electrode impedance, the electrically evoked compound action potential and behavioral measures in Nucleus 24 cochlear implant users. Ear Hear, 2001; 22(6): 471–86.
Zimmerling MJ, Hochmair ES. EAP recordings in CI patients – correlations with psychophysical measures and possible implications for patient fitting. Ear Hear, 2002; 23: 81–91.
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