Expanding pediatric cochlear implant candidacy: A case study of electro-natural stimulation (ENS) in partial deafness treatment

https://doi.org/10.1016/j.ijporl.2015.08.040Get rights and content

Abstract

Background

Some adolescents have hearing impairments characterized by normal or slightly elevated thresholds in the low and mid-frequency bands (below 1500 Hz) and nearly total deafness in the high frequency range. These patients often remain beyond the scope of effective hearing aid treatment.

Case report

This study presents the case of a 16-year-old adolescent with good hearing in the range 125–1500 Hz and deafness at other frequencies. An implant was used to restore hearing at high frequencies, while preserving low and mid frequency acoustic hearing in the implanted ear. This is described as electro-natural stimulation (ENS) of the inner ear.

Conclusions

The results demonstrate that low and mid frequency hearing (up to 1500 Hz) can be preserved using the round window surgical technique. A substantial improvement in speech discrimination was also observed when electrical stimulation on one side was combined with acoustic stimulation on both sides. There is scope to extend qualifying criteria for cochlear implantation to include adolescents who are suited to ENS.

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)

  • B. Schramm et al.

    Auditory, speech and language development in young children with cochlear implants compared with children with normal hearing

    Int. J. Pediatr. Otorhinolaryngol.

    (2010)
  • H. Skarżyński et al.

    Partial deafness cochlear implantation in children

    Int. J. Pediatr. Otorhinolaryngol.

    (2007)
  • M. Mondain et al.

    Cochlear implantation in prelingually deafened children with residual hearing

    Int. J. Pediatr. Otorhinolaryngol.

    (2002)
  • A. Kral et al.

    Profound deafness in childhood

    N. Engl. J. Med.

    (2010)
  • M. Bond et al.

    Effectiveness of multi-channel unilateral cochlear implants for profoundly deaf children: a systematic review

    Clin. Otolaryngol.

    (2009)
  • C. Yoshinaga-Itano 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)
  • N. Quaranta et al.

    Cochlear implants: indications in groups of patients with borderline indications. A review

    Acta Otolaryngol. Suppl.

    (2004)
  • J.H. Cadieux et al.

    Cochlear implantation in nontraditional candidates: preliminary results in adolescents with asymmetric hearing loss

    Otol. Neurotol.

    (2013)
  • A. Peasgood et al.

    Performance Benefit as outcome measures following cochlear implantation in non-traditional adult candidates: a pilot study

    Cochlear Implants Int.

    (2003)
  • R. Santarelli et al.

    Cochlear implantation outcome in prelingually deafened young adults: a speech perception study

    Audiol. Neurootol.

    (2008)
  • I.A. Bruce et al.

    Hearing preservation cochlear implantation in adolescents

    Otol. Neurotol.

    (2014)
  • H. Skarżyński et al.

    Electro-natural stimulation (ENS) in partial deafness treatment: a case study

    J. Hear Sci.

    (2014)
  • H. Skarżyński et al.

    A new method of partial deafness treatment

    Med. Sci. Monit.

    (2003)
  • Cited by (26)

    • Vestibular status in partial deafness

      2021, Brazilian Journal of Otorhinolaryngology
      Citation Excerpt :

      The patients were divided into four groups according to their hearing thresholds and their low frequency hearing. We based the division on the Partial Deafness Treatment (PDT) classification (Figs. 1 and 2).14–17 The classification refers the patients who are partially deaf, so have detectable hearing thresholds within the limits of audiometer that need to be protected and result in different surgical strategies of cochlear implantation according to the degree of preserved hearing.

    • Pediatric Cochlear Implantation

      2021, Cummings Pediatric Otolaryngology
    • Tonotopic organisation of the auditory cortex in sloping sensorineural hearing loss

      2017, Hearing Research
      Citation Excerpt :

      Studies in pediatric congenitally deaf recipients of cochlear implants consistently show largest benefits when the implantation is performed within the first 4 years of life. This time coincides with the sensitive periods of auditory development and peaks of synaptogenesis (Sharma et al., 2015; Hofer et al., 2009; Moeller et al., 2007; Skarżyński et al., 2015). The outcomes of the current study are in agreement with findings presented in a paper by Striem-Amit et al. (2016) who used an fMRI measure of functional connectivity (reflecting coherent functional brain networks which exist during resting state) to investigate the tonotopic organisation of the auditory cortex in congenitally deaf patients.

    • Validation of the LittlEARS Auditory Questionnaire in cochlear implanted infants and toddlers

      2017, International Journal of Pediatric Otorhinolaryngology
      Citation Excerpt :

      “Early experience with HAs”, as well as the “amount of residual hearing” before implantation, are other factors which can affect the performance of CI children. However, existing studies which have reported on children with substantial residual hearing only involved children older than 5 years [2,36,37]. Therefore, based on the findings described above, we expected that there would be group differences in LEAQ scores between: 1) early and late implanted children; 2) children with long and short HA experience prior to implantation; and 3) children with HAs who demonstrated responses over a wide frequency range prior to implantation vs those who did not.

    • Worldwide Variation in Cochlear Implant Candidacy

      2022, Journal of International Advanced Otology
    View all citing articles on Scopus
    View full text