Unimodal versus bimodal auditory stimulation in inner ear malformations: Cognitive, language, and motor performance

Purpose

New perspectives on rehabilitation options for inner ear malformations have still been studied in the literature. This study investigated the cognitive, language, and motor skills of auditory brainstem implant (ABI) users in unimodal and bimodal groups.

Methods

The motor competency of the participants was assessed with Bruininks-Oseretsky Motor Proficiency Test-2 Short Form (BOT2 SF). Language performance was evaluated by the test of Early Language Development-3 and Speech Intelligibility Rating. Word identification, sentence recognition tests, and Categories of Auditory Performance were used to assess auditory perception skills. To examine the cognitive performance, Cancellation Test and Gesell Copy Form were administered. All the tests were conducted in a quiet environment without any distractions.

Results

The participants were divided into two groups: (1) 17 children in the unimodal group and (2) 11 children in the bimodal (who used a cochlear implant on one side and ABI on the other side) group. There were significant correlations between the chronological age of participants and BOT2 SF total score, cancellation tests, auditory perception tests, and language performance. Similarly, there were significant correlations between the duration of ABI use and auditory perception tests, language performance, cancellation test, and some BOT2 SF subtests (r = -0.47 to -0.60, p < .001). There was no significant difference between the unimodal and bimodal groups in any task (p > .05). However, there were moderate-to-strong correlations among the auditory perception tests, cancellation test, language test, and BOT2 SF total score and subtests (r = 0.40 to 0.55, p < .05).

Conclusion

Although there were no significant differences between bimodal and unimodal groups, a holistic approach, which indicates that hearing and balance issues can have broader impacts on a person's physical, emotional, social, and psychological aspects, should be used in the assessment process.

Level of Evidence

Level 4.

Expressive Vocabulary Growth After Pediatric Auditory Brainstem Implantation in Two Cases' Spontaneous Productions: A Comparison With Children With Cochlear Implants and Typical Hearing

Auditory brainstem implants (ABI) are recently being used to restore hearing of children with a congenital hearing loss, due to for instance the absence of auditory nerves. Thus far, the literature has focused on perceptual outcomes. The present study is among the first ones to investigate the spoken language development after implantation. The lexical development of children with ABI is examined longitudinally in comparison to children with typical hearing and children with cochlear implants. Results show that children with ABI still have smaller spoken vocabularies as compared to (hearing) age-matched children with cochlear implants and children with typical hearing. Implications will be discussed.

Cochlear implantation after radiation therapy for acoustic neuroma

Neurofibromatosis type 2 (NF-2) represents the complex issue of hearing restoration after treatment for a patient with bilateral acoustic neuromas. This scenario is difficult for skull base teams considering that all treatment options (including observation of tumors) pose a risk to the patient for further or total hearing loss. In this case of a patient with bilateral deafness, restoration options were auditory brainstem or cochlear implantation (CI). The deciding factor for CI was based on the presence of a functioning cochlear nerve and blood supply. Ultimately, treatment with radiation therapy and subsequent CI proved effective as evidenced by dramatic improvement in communication (with lip reading cues) and speech perception on 1-year audiologic testing. Radiosurgery followed by CI may represent a potential emerging option for patients with NF-2.

Nervus Intermedius Guides Auditory Brainstem Implant Surgery in Children with Cochlear Nerve Deficiency

OBJECTIVE

To investigate the anatomic features of the nervus intermedius and cranial nerve VII in children with cochlear nerve deficiency and to verify whether the nervus intermedius can provide an additional landmark to help guide placement of the auditory brainstem implant electrode.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

High-definition video was captured during retrosigmoid surgery in 64 children (mean age, 3.91 ± 2.83 years) undergoing auditory brainstem implant placement. These videos were examined with particular reference to the number and variety of nervus intermedius bundles and any associated facial nerve anomalies.

RESULTS

Absence of cranial nerves VI, VII, and VIII was observed in 3, 6, and all 64 children, respectively. Fifteen children had several abnormalities of the facial nerve in the cerebellopontine angle. Anatomic identification of the facial nerve and the bundles composing the nervus intermedius was possible in 46 children. In 12 children, identification was possible with the assistance of intraoperative monitoring. The number of bundles composing the nervus intermedius varied from 1 to 6. The nervus intermedius and cranial nerve IX were useful landmarks for identifying the foramen of Luschka of the lateral recess.

CONCLUSION

The nervus intermedius provides an additional landmark during auditory brainstem microsurgery since it was identified in all subjects. The nervus intermedius anatomy and its topographic relationship with the neurovascular structures around the foramen of Luschka have been described for the first time in children with cochlear nerve deficiency.