Cochlear Implantation in Pediatrics: The Effect of Cochlear Coverage

Abstract

The effect of insertion depth and position of cochlear implant (CI) electrode arrays on speech perception remains unclear. This study aimed to determine the relationship between cochlear coverage and speech performance in children with prelingual hearing loss with CI. Pure tone audiometry (PTA) and speech audiometry, including speech reception threshold (SRT) using spondee words and speech discrimination score (SDS) using phonetically balanced monosyllabic words, were tested. The Categories of Auditory Performance (CAP) and Speech Intelligibility Rating (SIR) scales were also used. Thirty-one ears were implanted with the FLEX 28 electrode array, and 54 with the FORM 24 were included in the current study. For the studied ear, the mean cochlear duct length was 30.82 ± 2.24 mm; the mean cochlear coverage was 82.78 ± 7.49%. Cochlear coverage was a significant negative predictor for the mean pure tone threshold across frequecnies of 0.5, 1, 2, and 4 kHz (PTA4) (p = 0.019). Cochlear coverage was a significant positive predictor of SDS (p = 0.009). In children with cochlear coverage ≥ 82.78%, SDS was significantly better than in those with coverage < 82.78% (p = 0.04). Cochlear coverage was not a significant predictor of the SRT, CAP, or SIR. In conclusion, the cochlear coverage of the CI electrode array has an impact on the users’ SDS. Further long-term studies with larger sample sizes should be conducted to address the most critical factors affecting CI recipients’ outcomes.

Aktuelle Trends und Entwicklungen bei der Cochlea-Implantat-Versorgung

“…Neuere Untersuchungen 16 17 zur Anatomie der Cochlea mit Synchrotron Röntgenbildern legen nahe, dass der Apex der Cochlea (über 720 o hinaus) variabler angelegt ist als bisher gedacht. Bezieht man diese Untersuchungen in die Überlegungen zur tiefen Elektrodeninsertion mit ein, so scheint sich ein Optimum für die Elektrodeninsertion bei einer elektrischen Abdeckung von 80–85 % der cochleären Länge, entsprechend ±720 o abzuzeichnen 53 54 . Dass dabei eine gering traumatisierende Scala-tympani-Insertion bis weit in die zweite Windung der Cochlea ohne Skalensprung möglich ist, ist seit Ende der 90iger Jahre des vergangenen Jahrtausends bekannt 55 56 .…”

Simultaneous Bilateral Cochlear Implantation in Adults

“…Cochlear implants (CIs) are a surgically implantable device beneath the skin and over the temporal bone with an electrode array inserted into the damaged cochlea [6]. They are considered a potential alternative to hearing aids because they replace the role of hair cells that can no longer generate electrical impulses in response to noises by transmitting these electrical impulses directly to the spiral ganglion neurons and the cochlear nerve [6,7].…”

“…Cochlear implants (CIs) are a surgically implantable device beneath the skin and over the temporal bone with an electrode array inserted into the damaged cochlea [6]. They are considered a potential alternative to hearing aids because they replace the role of hair cells that can no longer generate electrical impulses in response to noises by transmitting these electrical impulses directly to the spiral ganglion neurons and the cochlear nerve [6,7]. Initially, only those with profound bilateral deafness were considered candidates for cochlear implants; however, as cochlear implant technology and processing strategies advanced over the years, the candidacy criteria for CI surgery were expanded for both adults and children, with a wide range of indications [8].…”