Speech Recognition Performance in Children with Cochlear Implants Using Bimodal Stimulation

Cochlear implantees have considerably good speech understanding abilities in quiet surroundings. But, ambient noise poses significant difficulties in understanding speech for these individuals. Bimodal stimulation is still not used by many Indian implantees in spite of reports that bimodal stimulation is beneficial for speech understanding in noise as compared to cochlear implant alone and also prevents auditory deprivation in the un-implanted ear. The aim of the study is to evaluate the benefits of bimodal stimulation in children in an Indian cochlear implant clinic. A group of 14 children who have been using cochlear implants served as subjects in this study. They were fitted with advanced digital hearing aids in their un-implanted ears to provide bimodal stimulation. Results revealed that bimodal stimulation did not bring greater change in speech scores in quiet surroundings but have shown a noticeable improvement in noisy ambience. Hence the present study suggests that bimodal stimulation would benefit children with cochlear implants especially in adverse listening conditions.     

Early Speech Perception Test Outcome in Children with Severe Sensorineural Hearing Loss with Unilateral Cochlear Implants Alone versus Bimodal Stimulation

Bilateral stimulation of the auditory system has clear advantages over unilateral hearing. Hearing-impaired children are, therefore, generally fitted with hearing aids in both ears so that they can have the benefits of binaural hearing. Children who use acochlear implant in one ear and no acoustic stimulation in the opposite ear are at a definite disadvantage. This study was undertaken to determine the advantages of bimodal stimulation in pediatric population especially in terms of speech recognition. This study comprised of 30 children between 3 and 6 years of age with profound bilateral sensorineural hearing loss with cochlear implant in one ear and fitted with digital hearing aid in non-implanted ear. Speech recognition performance was compared in unilateral cochlear implant only and with bimodal hearing stimulation in the same set of children. A statistically significant difference was found between speech reception scores in children with a unilateral cochlear implant only and those with a cochlear implant in one ear and a hearing aid in the non implanted ear in quiet surroundings. It is suggested that the use of bimodal fitting be considered as an effective management method to obtain the advantage of binaural hearing in children who undergo unilateral cochlear implantation.     

A Retrospective Clinical Audit of Outcomes of Cochlear Implantation in Children with Multiple Disabilities in Comparison with Normal Implantees: A South Indian Experience

AimsCochlear implantation (CI) is established as a standard remedy for children with congenital bilateral profound hearing loss to attain hearing perception and thereby develop speech and language. A subgroup includes children with multiple disabilities in whom the implant helps to improve their quality of life and also of their families via enhanced communication skills. Cochlear implants today form an integral part of their multi-handicap rehabilitation process.Material and MethodsA retrospective cohort study was carried out on children with and without multiple handicaps who have received cochlear implantation at the cochlear implant clinic of MERF, Chennai, India over the past decade. Category of Auditory Performance (CAP) scores, Speech Intelligibility Rating (SIR) scores, and also Meaningful Auditory-Integration Scale (MAIS) and Meaningful Use of Speech Scale (MUSS) scores were compared at set time frequencies of 6 months and 12 months post-implantation between the two groups of implanted children.ResultsAll the four CAP, SIR, MAIS and MUSS scores showed improvement over time with auditory and speech therapy in both groups of children as reflected by the improvement in their quality of life. The normative group of implantees showed better improvement compared to the group of children with multiple disabilities.ConclusionIntensive habilitation is essential especially for children with multiple disabilities who have received cochlear implantation in which their special needs are addressed individually and optimised for the best outcome. The study shows that restoration of the special sense of hearing helps as a remedy to alleviate their other multi-handicaps to a notable extent.     

Pediatric cochlear implantation-I : Candidacy

The cochlear implant is a successful means of intervention to facilitate the perception of sound and oral communication for children with severe to profound sensorineural hearing loss. Often, the cochlear implantation process is viewed as being limited to a surgical procedure, rather than an entire process of medical, audiological, psychosocial, educational and therapeutic, management. In India, cochlear implantation is available in only a few large cities. Here, the otolaryngologist will direct the cochlear implant programme. Besides determination of medical candidacy, device implantation and medical management, the otolaryngologist is responsible to ensure that other aspects of cochlear implant management are implemented. This paper, the first of two that describe the multidisciplinary, team approach of the Pediatric Cochlear Implant Program of The Children’s Hospital of Philadelphia (CHOP), in Pennsylvania, USA, discusses the non-medical aspects of cochlear implant candidacy. A second article will follow that covers post-implantation follow- up. The various speech tests used at CHOP for assessment are based on the English language. They may be translated into the regional Indian languages where the assessment and training can be carried out accordingly.     

Pediatric cochlear implantation — II: postoperative follow-up

A child with a cochlear implant is expected to achieve the successful outcome of facilitated perception of sound and more oral communication. To achieve this goal, ongoing intervention from a variety of professionals is required. These professionals may represent the disciplines of medicine, audiology, social work, education, and speech / language pathology. In India, cochlear implantation is available in only a few large cities. Here, the otolaryngologist will direct the cochlear implant program. Besides determination of medical candidacy, device implantation and medical management, the otolaryngologist is responsible to ensure that other aspects of cochlear implant management are implemented. This paper, the second of two that describe the multidisciplinary, team approach of the Pediatric Cochlear Implant Program of The Children’s Hospital of Philadelphia (CHOP), in Pennsylvania, USA, discusses the non-medical aspects of cochlear implant post-implantation follow-up. The first article, previously published, discussed cochlear implant candidacy. The various speech tests used at CHOP for assessment are based on the English language. They may be translated into the regional Indian languages where the assessment and training can be carried out accordingly.     

Registering event-related auditory potentials (P300) in patients with cochlear implants

Event-related auditory evoked potentials can contribute to the evaluation of discrimination abilities of cochlear implant users. Auditory P300 potentials to a frequency contrast were obtained in six post-lingually deaf adults using a cochlear implant and in a control group of normal hearing subjects. The aim of this study was to investigate how these potentials were determined by the stimulation pattern of the cochlear implant. To visualise these stimulation patterns colour-coded plots (stimulograms) were calculated based on the stimulus and the fitting file of the individual subject as inputs. These stimulograms were used to evaluate the influence of various stimulation parameters on the stimulation contrast used in an oddball paradigm. The influence of discrimination difficulty on the P300 response is demonstrated.     

Current practice of paediatric chochlear implantation in nottingham

The number of integrated paediatric cochlear implantation programme are very few in the world. In U.K. this pioneering integrated paediatric chochlear implantation programme has been started in the year 1989 under the supervision of group of dedicated paediatric personnel comprising of ENT surgeons, neuro-radiologist, audiologist, speech therapist, orthophonists, teachers of the deaf and others associated with the deaf children. Only the surgical procedure of cochlear implantation is not the answer of a profound sensorineural deaf child who can not be helped by conventional hearing aids. Proper selection of the cases, pre-operative counselling, pre-operative audiological and non-audiological investigations are of immense value. Similarly the programme following surgery as a team approach is equally important for proper rehabilitation of profound sensorineural deaf child who can not be helped by conventional hearing aids.     

Cochlear Implant in Prelingually Deaf Children: Our Experience

Retrospective study of the prelingual cochlear implantation programme under government scheme done at medical college hospital in central India. Forty-two prelingually deaf children screened and sent for cochlear implantation at our centre From March 2015 to Feb 2018 were reviewed with respect to their age, sex, preimplantation hearing aid use, surgical technique for cochlear implantation, type of FDA (USA) approved cochlear implant, post operative speech therapy and its outcome with respect to categories of auditory perception and speech intelligibility scoring were compared for children younger than 4 years and older than 4 years. For outcome measurement non parametric statistical method was used for any significance between the two groups. There was a wide range of children implanted ranging from 2 to 7 years. Both varia and mastoidectomy and posterior tympanotomy method of cochlear implantations were done with good rate complete insertion and electrode activation. There was no significant difference between the two group with regard to CAP and SIR outcomes after 1 year. In order to get better outcomes with respect to the speech language development, there is need to strengthen the early identification and cochlear implantation before 4 years of age in government approved schemes.     

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.     

Trans-Aditus Approach: An Alternative Technique for Cochlear Implantation

The objective of this study was to report our preliminary experience with an alternative technique for cochlear implantation. Twenty patients underwent cochlear implantation via a trans-aditus ad antrum approach to the round window. The main steps involved in the surgical procedure are cortical mastoidectomy, elevation of tympanomeatal flap, incudostapedial joint dislocation, incus removal, preparation of a bed for the implant, cochleostomy via the external auditory canal, and finally insertion of the electrode into the cochlea via the aditus. Twenty-five implants were performed on 20 patients, 18 children (mean age of 3.2 years) and 2 adults. Twelve patients were males and eight were females. All the children were pre-lingual while the adults were post-lingual. Nucleus freedom cochlear implant system (Cochlear, Lane Cover, NSW, Australia) was used in four patients and a cochlear Nucleus 5 was used in six patients. A Med-el SONATA implant (MED-EL, Innsbruck, Austria) was used in 15 patients. The minimum follow-up was 5 months. Here, we describe a new alternative technique for cochlear implantation and report our preliminary results. The procedure has advantages over the existing techniques and avoids the potential complications of posterior tympanotomy, transcanal, and transmeatal techniques.     

A Study of Effect of Consanguinity on Cochlear Morphology in Patients with Congenital Bilateral Profound Sensorineural Hearing Loss

Consanguinity has been considered as one of the risk factors predisposing to the development of congenital hearing loss. Effect of consanguinity on cochlear morphology has been subject of speculation, though many studies have provided insight into functional aspect of cochlea. This study was conducted to know the effect of consanguinity on cochlear morphology, if any. A prospective, observational study, including prelingually deaf children with bilateral profound sensorineural hearing loss who are registered as candidates for cochlear implantation at a tertiary care centre, was conducted. Seven children born out of consanguineous marriages and having bilateral congenital sensorineural hearing loss were imaged for their inner ears by MRI and various cochlear measurements were compared with that of seven control children born out of non-consanguineous marriages and who had congenital bilateral sensorineural hearing deafness. No statistically significant differences were noticed in the measurements of mean cochlear length, cross sectional diameter of cochlea at apex, middle turn and at basal turns; between children born of consanguineous and non-consanguineous marriages. Study revealed normal cochlear morphology in all the children born out of consanguineous marriages. Consanguinity, as a risk factor for development of sensorineural hearing loss, may not result in gross structural anomaly of cochlea. The genetic testing of these patients need not be extensive and can be limited to selective screening of genes responsible for functioning of cochlea rather than its anatomical development.     

Compensated Vestibular Dysfunction Post Cochlear Implantation in Children with Sensorineural Hearing Loss: A Prospective Study

Children with sensorineural hearing loss have risk of surgically induced vestibular dysfunction post cochlear implantation due to instrumentation. It is clinically important to estimate the risk of vestibular loss post cochlear implant so the patient can be made fully aware of these risks when considering cochlear implantation. The aim of the study was to identify compensated vestibular dysfunction post cochlear implantation. Vestibular function was evaluated both pre and post CI using monothermal warm air caloric testing. Recordings were made using head band camera on SYNAPSYS Ulmer VNG software. ‘Monothermal caloric asymmetry’ (MCA) was depicted as ‘unilateral weakness’ based on the slow phase velocity of nystagmus. MCA of >15% was taken as evidence of canal paresis. The incidence of compensated vestibular dysfunction post CI surgery was found to be 16.66%. The results were statistically significant (p value 0.02) and indicated worsening of canal paresis indicative of vestibular dysfunction. Children for cochlear implantation should undergo evaluation of their vestibular system pre and post surgery. Caution should be exercised before planning bilateral cochlear implantation in the same sitting.     

Cochlear implants: response to therapeutic irradiation

PURPOSE: To determine the response of cochlear implants ("bionic ears") to therapeutic irradiation. METHODS AND MATERIALS: A patient with a cochlear implant was referred for palliative cranial irradiation. As there were no published or manufacturer's data available regarding the response to radiation, implants were tested for functional changes following irradiation. Cochlear implants were supplied by Cochlear Ltd. Two units each of models CI22M, CI22M (with the second generation integrated circuit) and CI24M were irradiated with 4 MV X-rays, and an unirradiated unit of each model was used as a control. The implants were irradiated initially with 25 daily fractions to 50 Gy. To determine the response at higher doses, 10 Gy fractions were delivered to the same implants to 100 Gy, followed by a final fraction of 50 Gy (total dose 150 Gy). The implants were tested after each 10 Gy, up to 1100 Gy, and at 150 Gy. Several indicators of functionality were assessed, including RF (radio frequency) link range, and stimulator output current. The radiation shielding effect of the implants was also assessed. RESULTS: Within the dose range < or = 50 Gy, the stimulator output current of the CI22M units was the only parameter to change. At higher doses (to 150 Gy), changes in current output continued, and gradual loss of RF link range occurred in the CI22M units. The CI24M units showed changes in output current to 100 Gy, and large changes at 150 Gy. Dose attenuation by the implants was measured at 6% for ipsilateral single field 4 MV X-rays. CONCLUSION: Our results suggest that patients with these cochlear implants can receive cranial irradiation with a low risk of implant failure. Changes in stimulator output current can be compensated simply by reprogramming the speech map after the course of radiation treatment.     

Neurofibromatosis 2: Primary Modality of Hearing Rehabilitation with Cochlear Implant

Auditory Brainstem Implants have been recommended as the gold standard in hearing rehabilitation of Neurofibromatosis Type 2 patients who lose hearing completely in both the ears and the cochlear nerves are not stimulable. Some patients have undergone cochlear implantation, in whom the cochlear nerve was spared during surgery or have undergone stereotactic radiotherapy preserving the function of the cochlear nerve. Here we report a case in whom we chose cochlear implantation prior to any definitive treatment for the tumour itself during the ‘wait and watch’ period. The reasons in favour of this approach have been discussed in this article. Post switch-on the implant is benefitting the patient satisfactorily and she is on regular follow up for monitoring the bilateral tumours.     

鼻咽癌调强放疗后感音神经性听力下降的临床分析

目的 分析鼻咽癌患者调强放疗后感音神经性听力下降(SNHL)的影响因素。方法 比较2012— 2013年间接受单纯放疗和同期放化疗的 29例鼻咽癌患者声导抗测听、纯音听阈测定及耳蜗放射剂量,所有患者均接受调强放疗。采用前瞻性分析方法分析耳蜗放射剂量对鼻咽癌患者SNHL的影响,同时了解放疗后时间、化疗、T分期、年龄等因素对结果的影响。结果 58只耳中6只(10%)发生了低频SNHL,17只(29%)发生高频SNHL。放疗后发生感音神经性耳聋患者和未发生听力下降患者耳蜗剂量不同(左耳46、1 Gy∶35、5 Gy,P=0、006;右耳45、0 Gy∶35、8 Gy,P= 0、009)。当耳蜗平均剂量限制到44 Gy以下时只有15%(6/38)耳发生SNHL。颅底骨质破坏对听力有影响(P=0、047)。结论耳蜗的平均剂量和颅底骨质的侵犯是鼻咽癌患者放疗后SNHL的重要影响因素。建议耳蜗的平均剂量限制在44 Gy是合理的。     

Measurement of implant stability and auditory pure-tone thresholds of Baha patients comparing osteosysthesis and osseointegrated systems

With bone-anchored hearing systems the implant-bone junction is critical for the transmission of mechanical vibrations to the skull. The implant stability might differ between available and widely applied implants and can be estimated by resonance frequency analysis.The implant stability and the audiological performance of ten adult long-time users where a bone-anchored hearing system was connected by an Baha osseointegrated implant (Cochlear Ltd, Mölnlycke, Sweden) were compared with the implant stability of fourteen adult patients provided with a Ti-epiplating osteosysthesis system (Medicon, Tuttlingen, Germany). The acute implant stability was compared between these two implants with one cadaveric skull.The results show higher resonance frequencies and thus higher implant stability for the osseointegrating system of both, measuring acute and after long-time use of the implants. The audiological outcomes show frequency dependent differences between both systems as determined by comparing pure-tone bone-conduction audiometry. However, measuring thresholds by a direct stimulation of the implant reveals better hearing with low frequencies for the osseointegrated system and for high frequencies with the osteosysthesis system. At all, the implant selection has an impact on the implant stability and on the pure-tone hearing.     

Hearing loss in children and young adults receiving cisplatin with or without prior cranial irradiation

One hundred seventy-seven children and young adults with various malignant neoplasms were prospectively tested for hearing loss after they had received cisplatin (n = 146), cranial irradiation (n = 18), or both (n = 13). Adequate renal function, no history of treatment with ototoxic drugs other than cisplatin, and availability for repeated audiometric testing were requirements for enrollment. Substantial hearing loss, defined as a hearing threshold of 50 dB or greater, was noted in only 11% of the cohort on tests conducted at the common speech frequencies (500 to 3,000 Hz). About half the patients had substantial deficits at higher frequencies (4,000 to 8,000 Hz). The probability of substantial hearing loss was directly related to the cumulative dose of cisplatin. In nonirradiated patients tested at the speech frequencies, there was a negligible risk of substantial deficits over the dose range of 90 to 360 mg/m2. As the dose increased to 720 mg/m2, the risk increased to 22%. In irradiated patients who later received cisplatin, cumulative drug doses as low as 270 mg/m2 were associated with a high probability of substantial hearing loss, suggesting potentiation of ototoxicity when these therapies are used together. Hearing acuity was either not affected or only minimally decreased in the irradiation-only group. Younger age, prior irradiation, and the presence of a CNS tumor each contributed significantly to the severity of hearing deficits at given cisplatin dose levels. We conclude that early increases in hearing threshold at a stimulus frequency of 4,000 Hz indicate probable subsequent deficits at lower frequencies, especially in young children with CNS tumors who have received cranial irradiation. The probability charts derived from this analysis should provide a useful tool for predicting hearing loss in the speech frequencies.     

Cochlear Implantation in Children with Anomalous Cochleovestibular Anatomy: Our Experience

To report operative findings, postoperative course, and postimplantation performance in patients with cochlear malformations who underwent cochlear implantation. Seventeen patients with malformations which included enlarged vestibular aqueduct (n = 6), Mondini’s dysplasia (n = 5) common cavity deformity (n = 3) and incomplete partition type 2 (n = 3) underwent cochlear implantation with Nucleus 22 straight array device at our center. Operative findings described facial nerve anatomy and cerebrospinal fluid leak. Standard tests of speech perception were used to evaluate the postoperative performance for each subject. Operative findings included cerebrospinal fluid leak (thirteen patients) all of which were repaired successfully with graft. None had abnormal facial nerve anatomy. No surgical complications occurred. All the patients except two with common cavity had complete insertion. Electrode thresholds and discomfort levels were variable for several months after implantation. All patients demonstrated improved performance after implantation. Patients with enlarged vestibular aqueduct fared better than patients with other inner ear malformations. Cochlear implantation can be a successful method of rehabilitation in patients with congenital deafness who have cochlear malformations.