International Journal of Pediatric Otorhinolaryngology
Expanding pediatric cochlear implant candidacy: A case study of electro-natural stimulation (ENS) in partial deafness treatment
Introduction
Traditionally, children are considered candidates for a cochlear implant (CI) if they have bilateral severe to profound sensorineural hearing loss (SPHL). It has been well established that early cochlear implantation leads to many benefits for deaf children, including an almost normal language development [1], [2], [3]. Children implanted in infancy outperform their peers who receive implants later, and often approach the abilities of normal-hearing children of the same age [4], [5]. This means that adolescents with prelingual deafness are now regarded as a special population that are only reluctantly considered suitable for a CI [6], [7].
However, recent work with prelingual adolescents who have residual hearing and oral communication, and who have been using hearing aids (HA) since childhood, has shown that their speech perception can be markedly improved after cochlear implantation [8]. There are now dedicated adolescent cochlear implant programs which address the unique challenges faced by adolescents with SPHL who struggle with hearing aids [9].
Notably, however, there is another group of adolescents whose hearing impairment is characterized by normal or slightly elevated thresholds in the low and mid-frequency bands with nearly total deafness in the high frequency range. This type of partial deafness remains beyond the bounds of effective treatment by hearing aids. The only practical way to improve hearing is to complement the normal hearing at low and mid frequencies with electric stimulation at higher frequencies using a cochlear implant. This arrangement is described as electro-natural stimulation (ENS) of the inner ear [10].
In previous reports, we have demonstrated the efficacy of applying electric stimulation to totally (or almost totally) inactive regions of the inner ear using a cochlear implant, thereby complementing the preserved low-frequency hearing [11], [12], [13], [14], [15], [16], [17], [18], [19], [20]. It has been called partial deafness treatment–electric complementation (PDT–EC) [16], [18], [19]. In the conception introduced by Skarzynski in 2002 in adults and in 2004 in children, frequencies up to 500 Hz are complemented [12], [14], providing a significant extension of the previously accepted indications for cochlear implantation. Subsequently, the underlying theory behind PDT has been further developed, and a thorough description was published in 2010 [16] (Fig. 1).
In summary, PDT has three approaches for dealing with three distinct groups of patients [15], [17], [18]. (1) EC in patients who have normal or slightly elevated thresholds at low frequencies and almost total deafness at higher frequencies. Here, non-amplified low frequency hearing is complemented by electric stimulation with a cochlear implant. (2) Electric-Acoustic Stimulation (EAS) in patients with mild-to-severe hearing loss at low frequencies and profound hearing loss at high frequencies. In this group, low frequency hearing is amplified and combined with electric stimulation in the same ear. (3) Electric Stimulation (ES) in cases with non-functional hearing.
This report presents the results of treating an adolescent with a hearing deficit diagnosed as partial deafness, in whom the natural hearing below 1500 Hz was complemented by means of electric stimulation in the frequency range above 1500 Hz. We describe the electric complementation of the almost natural hearing up to 3000 Hz as ENS [10]. This represents a new step forward, opening up the possibility of extending current indications for cochlear implantation.
Section snippets
Case description
The case was a 16-year-old boy who, at the time of implantation, had fully efficient hearing in the frequency range 125–1500 Hz and deafness at other frequencies (Table 1; Fig. 2). The bilateral hearing loss was prelingual, probably caused by an ototoxic drug (gentamicin) used shortly after birth.
Discussion and conclusion
Until now there has been very little information about preservation of hearing after a CI in adolescents with significant low frequency hearing. So far there has been only one published study aimed at determining if hearing could be successfully preserved in this population [9]. In this work, the study group consisted of 14 profoundly deaf adolescents with much lower levels of preoperative hearing than in the case here (being in the range of PDT–EAS according to the Skarzynski concept of Fig. 1
Acknowledgments
The work was supported by the Polish National Science Centre, decision no. DEC-013/09/B/ST7/04213. The authors thank Andrew Bell for comments on this article.
References (26)
- et al.
Auditory, speech and language development in young children with cochlear implants compared with children with normal hearing
Int. J. Pediatr. Otorhinolaryngol.
(2010) - et al.
Partial deafness cochlear implantation in children
Int. J. Pediatr. Otorhinolaryngol.
(2007) - et al.
Cochlear implantation in prelingually deafened children with residual hearing
Int. J. Pediatr. Otorhinolaryngol.
(2002) - et al.
Profound deafness in childhood
N. Engl. J. Med.
(2010) - et al.
Effectiveness of multi-channel unilateral cochlear implants for profoundly deaf children: a systematic review
Clin. Otolaryngol.
(2009) - et al.
Describing the trajectory of language development in the presence of severe-to-profound hearing loss: a closer look at children with cochlear implants versus hearing aids
Otol. Neurotol.
(2010) - et al.
Cochlear implants: indications in groups of patients with borderline indications. A review
Acta Otolaryngol. Suppl.
(2004) - et al.
Cochlear implantation in nontraditional candidates: preliminary results in adolescents with asymmetric hearing loss
Otol. Neurotol.
(2013) - et al.
Performance Benefit as outcome measures following cochlear implantation in non-traditional adult candidates: a pilot study
Cochlear Implants Int.
(2003) - et al.
Cochlear implantation outcome in prelingually deafened young adults: a speech perception study
Audiol. Neurootol.
(2008)
Hearing preservation cochlear implantation in adolescents
Otol. Neurotol.
Electro-natural stimulation (ENS) in partial deafness treatment: a case study
J. Hear Sci.
A new method of partial deafness treatment
Med. Sci. Monit.
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