Blog Archives

Cochlear implantation in children with labyrinthine anomalies and cochlear nerve deficiency: Implications for auditory brainstem implantation

Children with IP-EVA malformations have an excellent prognosis for developing open-set speech perception and using oral communication modes following CI. On the contrary, children with severe malformations o CND may have elevated charge requirements for attaining sound detection alone. These children’s prognosis for obtaining open-set speech understanding, using exclusive oral communication, and participating in mainstream education is more limited. These findings have important implications for considering alternative forms of intervention such as auditory brainstem implantation and/or supplementation with visually based communication strategies. Laryngoscope, 2011.

from The Laryngoscope

The relationship between binaural benefit and difference in unilateral speech recognition performance for bilateral cochlear implant users

Conclusions: The results indicate that subjects who show symmetry in speech recognition performance between implanted ears in general show a large binaural benefit.

from the International Journal of Audiology

Voice gender discrimination provides a measure of more than pitch-related perception in cochlear implant users

Conclusions: VGD measured with selected stimulus sets might be useful for assessing not only pitch-related perception, but also spectral and temporal processing by individual CI users. In addition to improvements in spectral resolution and modulation detection, the improvement in higher modulation frequency discrimination might be particularly important for CI users in noisy environments.

from the International Journal of Audiology

Temporal and Spectral Cues for Musical Timbre Perception in Electric Hearing

Conclusions: Temporal envelope was a dominant cue for timbre perception in CI listeners. Compared to NH listeners, CI listeners showed reduced reliance on both spectral envelope and spectral fine structure cues for timbre perception.

from the Journal of Speech, Language, and Hearing Research

The development of auditory skills in infants with isolated Large Vestibular Aqueduct Syndrome after cochlear implantation

Auditory skills of infants with isolated LVAS developed rapidly after cochlear implantation, in a similar manner to those of infants with a normal inner ear. Cochlear implantation is an effective interventional approach and an established therapeutic option for infants with isolated LVAS.

from the International Journal of Pediatric Otorhinolaryngology

Nerve Maintenance and Regeneration in the Damaged Cochlea

Following the onset of sensorineural hearing loss, degeneration of mechanosensitive hair cells and spiral ganglion cells (SGCs) in humans and animals occurs to variable degrees, with a trend for greater neural degeneration with greater duration of deafness. Emergence of the cochlear implant prosthesis has provided much needed aid to many hearing impaired patients and has become a well-recognized therapy worldwide. However, ongoing peripheral nerve fiber regression and subsequent degeneration of SGC bodies can reduce the neural targets of cochlear implant stimulation and diminish its function. There is increasing interest in bio-engineering approaches that aim to enhance cochlear implant efficacy by preventing SGC body degeneration and/or regenerating peripheral nerve fibers into the deaf sensory epithelium. We review the advancements in maintaining and regenerating nerves in damaged animal cochleae, with an emphasis on the therapeutic capacity of neurotrophic factors delivered to the inner ear after an insult. Additionally, we summarize the histological process of neuronal degeneration in the inner ear and describe different animal models that have been employed to study this mechanism. Research on enhancing the biological infrastructure of the deafened cochlea in order to improve cochlear implant efficacy is of immediate clinical importance.

from Hearing Research

Genetic characteristics in children with cochlear implants and the corresponding auditory performance

A significant prevalence of genetic mutations was identified in children with CIs, suggesting the need for routine genetic assessments. The frequencies of common deafness-associated mutations were different between children with and without CIs. The presence of genetic mutations was associated with an excellent long-term auditory performance outcome after implantation.

from The Laryngoscope

Outcome of cochlear implantation in asymptomatic congenital cytomegalovirus deafened children†‡

Children with asymptomatic deafness caused by cCMV benefit from cochlear implantation but perform less well than a comparable group of implanted children who do not have cCMV. There is a range of performance in the cCMV group which may relate to the degree of motor or cognitive disabilities.

from The Laryngoscope

Children with hearing impairment – Living with cochlear implants or hearing aids

Children with cochlear implants and children with hearing aids have, in some aspects, equally good functioning in everyday life situations. However, certain differences were found in dimensions of functioning, regarding neck and shoulder pain, usage of aids and sign language, and hearing problems in some activities.

from the International Journal of Pediatric Otorhinolaryngology

An improved cochlear implant electrode array for use in experimental studies

Experimental studies play an important role in establishing the safety and efficacy of cochlear implants and they continue to provide insight into a new generation of electrode arrays and stimulation strategies. One drawback has been the limited depth of insertion of an electrode array in experimental animals. We compared the insertion depth and trauma associated with the insertion of Cochlear Ltd’s Hybrid-L (HL) array with a standard 8 ring array in cat cochleae. Both arrays were inserted into cadaver cochleae and an X-ray recorded their anatomical location. The implanted cochlea was serially sectioned and photographed at 300μm intervals for evidence of electrode insertion trauma. Subsequently two cats were chronically implanted with HL arrays and electrically-evoked potentials recorded over a three month period. Mean insertion depth for the HL arrays was 334.8° (SD = 21°; n = 4) versus 175.5° (SD = 6°; n = 2) for the standard array. This relates to ˜10.5 mm and 6 mm respectively. A similar insertion depth was measured in a chronically implanted animal with a HL array. Histology from each cadaver cochleae showed that the electrode array was always located in the scala tympani; there was no evidence of electrode insertion trauma to the basilar membrane, the osseous spiral lamina or the spiral ligament. Finally, evoked potential data from the chronically implanted animals exhibited significantly lower thresholds compared with animals implanted with a standard 8 ring array, with electrical thresholds remaining stable over a three month observation period. Cochlear Ltd’s HL electrode array can be safely inserted ˜50% of the length of the cat scala tympani, placing the tip of the array close to the 4 kHz place. This insertion depth is considerably greater than is routinely achieved using a standard 8-ring electrode array (˜12 kHz place). The HL array evokes low thresholds that remain stable over three months of implantation. This electrode array has potential application in a broad area of cochlear implant related research.

from Hearing Research

Bilateral Simultaneous Cochlear Implantation in Children: Report of a Case and Review of Literature

The benefits of bilateral cochlear implant in adults are well established. Auditory ability in children is also substantially improved by binaural hearing. We report the first case of bilateral simultaneous paediatric cochlear implant in India and discuss the merits of bilateral implant.

from the Indian Journal of Otolaryngology

Mandarin Chinese speech recognition by pediatric cochlear implant users

Consistent with previous studies’ findings, early implantation provided a significant advantage for profoundly deaf children. Performance for both groups was generally quite good for the relatively difficult materials and tasks, suggesting that open-set word and sentence recognition may be useful in evaluating speech performance with older pediatric CI users. Differences in disyllable recognition between Groups 1 and 2 may reflect differences in adaptation to electric stimulation. The Group 1 subjects developed speech patterns exclusively via electric stimulation, while the Group 2 subjects adapted to electric stimulation relative to previous acoustic patterns.

from the International Journal of Pediatric Otorhinolaryngology

Children with bilateral cochlear implants: variability in the results

We reviewed data from a sample of 30 children (aged 1-12 years old) with bilateral implants enrolled in an integration school in Madrid. This study was prompted by the observation of differences in a small, but significant, number of children.

The variables analyzed were age at implantation, differences in the interval between the two implantations, choice of the first ear to undergo implantation, and the use or non-use of a contralateral hearing aid between the first and second implantations.

None of these variables was clearly related to difficulties but there were some indications that age at implantation and having always used a hearing aid in the ear with the later implant may be important factors.

Despite the generally favorable results, this study stresses the need to bear in mind individual variations that naturally concern families and education professionals.

The final section of the article discusses the implications of sequential bilateral implantation of cochlear implants in clinical practice in speech therapy.

from Revista de Logopedia, Foniatría y Audiología

Tinnitus Suppression by Low-Rate Electric Stimulation and Its Electrophysiological Mechanisms

Tinnitus is a phantom sensation of sound in the absence of external stimulation. However, external stimulation, particularly electric stimulation via a cochlear implant, has been shown to suppress tinnitus. Different from traditional methods of delivering speech sounds or high-rate (>2,000 Hz) stimulation, the present study found a unique unilaterally-deafened cochlear implant subject whose tinnitus was completely suppressed by a low-rate (<100 Hz) stimulus, delivered at a level softer than tinnitus to the apical part of the cochlea. Taking advantage of this novel finding, the present study compared both event-related and spontaneous cortical activities in the same subject between the tinnitus-present and tinnitus-suppressed states. Compared with the results obtained in the tinnitus-present state, the low-rate stimulus reduced cortical N100 potentials while increasing the spontaneous alpha power in the auditory cortex. These results are consistent with previous neurophysiological studies employing subjects with and without tinnitus and shed light on both tinnitus mechanism and treatment.

from Hearing Research

Adult cochlear implantation in Canada: Results of a survey

This paper presents the results of a survey of the adult cochlear implant centres in Canada. The survey was conducted in 2008 to examine trends in the cochlear implantation of adults in Canada between 1995 and 2007. All 12 Canadian programs, including nine surgical and three non-surgical centres, returned the questionnaire. The results showed that there has been signifi cant growth in adult cochlear implantation over the past 12 years, particularly since 1999. By 2007, a total of 2,534 adults had received implants in Canadian centres, 270 prior to 1995 and 2264 in the twelve-year period covered by this survey. In the past fi ve years (2003 through 2007), on average, 296 patients have received implants annually in Canada. The majority of adults who receive implants are under age 60; however, a notable trend in recent years is the implantation of adults over the age of 80 years. Major areas of concern for the centres are related to clinical resources (10 of 12 centres), clerical support (5 of 12) and surgical services (4 of 12). Respondents perceived that patients were most concerned about: 1) the costs of maintaining and upgrading their devices and, 2) access to both assessment and surgery in a timely manner. Respondents rated borderline audiologic candidacy, bilateral implantation and bimodal hearing (use of a cochlear implant and hearing aid) as the primary issues of interest for clinical discussions. These data provide baseline information about adult cochlear implant services in Canada that may assist in program planning and resource allocation.

from the Canadian Journal of Speech-Language Pathology and Audiology