ORIGINAL ARTICLE
CLINICAL STUDY OF AIDED CORTICAL AUDITORY EVOKED POTENTIALS IN PEDIATRIC AUDITORY BRAINSTEM IMPLANTEES
 
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Department of Auditory Implants, Madras ENT Research Foundation, Raja Annamalai Puram, Chennai, Tamil Nadu, India
CORRESPONDING AUTHOR
Raghunandhan Sampathkumar   

Dr Raghunandhan Sampathkumar, Department of Auditory Implants, Madras ENT Research Foundation, Raja Annamalai Puram, Chennai, Tamil Nadu, India 600 028, e-mail: raghunandhansampath@gmail.com
Publication date: 2020-04-17
 
J Hear Sci 2013;3(2):22–29
 
KEYWORDS
ABSTRACT
Background:
Cortical auditory evoked potentials (CAEPs) reflect the function of the auditory thalamo-cortical pathways and the auditory cortex, and so are a window to the ‘auditory brain’. They are a valuable prognosticator for predicting long-term outcomes in cochlear implantees. This preliminary study evaluated its use in pediatric auditory brainstem implant (ABI) who had bilateral Michel’s deformity with cochlear nerve hypoplasia.

Objectives:
To profile the aided CAEPs in children with ABI and to assess its efficacy as a tool for evaluating ABI outcomes.

Method:
This prospective clinical study was performed in 3 pre-lingually deaf, non-syndromic children (aged 3–5 yrs) who had congenital bilateral hypoplastic cochlear nerves with Michel’s cochlear deformity who underwent ABI at our institute. All implantees underwent CAEP testing at 6 months and 1 year post-implantation and their results were compared. To compare responses between the various electrodes in contact with the brainstem the 12 ABI electrodes were divided into 4 groups (G1–G4). These groups were sequentially activated and the CAEPs recorded; the responses were compared to the overall CAEP response obtained by stimulating the entire electrode array. Testing comprised /m/, /g/, and /t/ acoustic stimuli and responses to them were recorded from each group of electrodes. Latency of P1, amplitude of P1 complex, and morphology of the responses were analyzed.

Conclusions:
Results from our preliminary study showed that CAEP can be successfully recorded in ABI, and CAEP profiling can be an objective method of analyzing the optimal placement and function of the ABI electrodes on the brainstem. Thus CAEP is an efficient adjunct to electrically evoked auditory brainstem response (EABR) for testing ABIs. When stimulated via the ABI, CAEP may reflect re-organization of higher auditory centers and hence may be a good prognosticator for long-term assessment of ABI performance.

 
REFERENCES (5)
1.
Sharma A, Dorman MF, Spahr AJ. A sensitive Period for the Development of the Central Auditory System in Children with Cochlear Implants: Implications for Age of Implantation. Ear Hear, 2002; 23: 532–39.
 
2.
Sharma A, Nash AA, Dorman MF. Cortical development, plasticity and re-organization in children with cochlear implants. J Commun Disord, 2009; 42: 272–79.
 
3.
Kirk K, Miyamoto R, Lento C, Ying E, O’Neill T, Fears B. Effects of age at implantation in young children. Ann Otol Rhinol Laryngol Suppl, 2002; 189: 69–73.
 
4.
Dorman, MF, Sharma A, Gilley P, Martin K, Ronald P. Central auditory development: evidence from CAEP measurements in children fit with cochlear implants. J Commun Disord, 2007; 40: 284–94.
 
5.
Kral A, Tillein J, Heid S, Hartmann R, Klinke R. Postnatal cortical development in congenital auditory deprivation. Cereb Cortex, 2005; 15(5): 552–62.