Cochlear implantation

Cochlear implants are the single greatest advancement of the late 20th century for the deaf and hearing impaired. Recent expanding guidelines as well as surgical techniques are discussed. Cochlear implantation is currently the only means to restoring partial hearing to patients with severe-to-profound sensorineural loss not aidable with conventional amplification.     

Cochlear implantation in children

Cochlear implantation has revolutionized the treatment and prognosis of children with severe to profound sensorineural hearing loss who receive limited benefits from hearing aids. Children who receive cochlear implantation at young age, in particular before 2 years of age, can be expected to reach their normal age-equivalent developmental milestones and have higher chance to integrate into the mainstream educational settings. With the positive outcomes after cochlear implantation and the improvements in technology and surgical techniques, candidacy for cochlear implantation in children has been expanding to include hearing-impaired children with significant residual hearing, severe inner ear malformations, multiple handicaps such as mental retardation or visual impairment, and auditory neuropathy. Furthermore, there is growing interest in offering bilateral cochlear implantation to give children the benefits of binaural hearing. As the candidacy criteria expand, cochlear implant programs including preoperative evaluation, surgery, and habilitation have become more complex. Therefore, candidates should be selected prudently by multidisciplinary approach and cochlear implantation in children is much better to be provided by experienced cochlear implant team consisting of experts in relevant fields for the best results.     

Cochlear implantation in superficial siderosis

Superficial siderosis (SS) of the central nervous system has been thought to be a rare condition that generates progressive hearing loss, ataxia, pyramidal signs, and dementia. The main cause of hearing loss by SS is thought to be neuronal. Because there is no histopathologic report of the human temporal bone in SS, there is a debate about the possibility of cochlear involvement. We present a 25-year-old man who was investigated for bilateral progressive sensorineural hearing loss and vestibular failure after head trauma. On brain MRI, SS of the central nervous system was detected. Distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) showed no response on both sides. However, integrity of the eighth nerve was proved by the electrical ABR test on the right side and the patient benefited significantly from cochlear implantation. The sensorineural hearing loss in SS seems to be related to cochlear damage as well as neuronal damage. So, cochlear implantation would be a hearing rehabilitation modality for the sensorineural hearing loss caused by SS.     

Cochlear implantation in Refsum's disease

Abstract

Refsum's disease is a rare disorder characterized by accumulation of phytanic acid in plasma and tissues. The main clinical features are retinitis pigmentosa, cerebellar ataxia and chronic polyneuropathy. Sensorineural hearing loss of varying severity can be an additional feature. This study reports our experience with two patients with Refsum's disease who underwent successful cochlear implantation. Both patients had good audiological outcomes after implantation and were overall very satisfied. Bilateral implantation should be considered with patients with severe dual sensory loss. One patient was implanted bilaterally the other unilaterally, primarily due to prolonged duration of unaided unilateral profound hearing loss. Copyright © 2008 John Wiley & Sons, Ltd.     

Cochlear implantation in Waardenburg's syndrome

Conclusions. Children with Waardenburg's syndrome (WS) derive significant benefit from cochlear implantation (CI) and do so to an extent that is comparable to that of the general population of implanted children. Although we report on a relatively small cohort, our data are useful for counseling the parents of children with WS considering CI. Objective. To present our experience with CI in patients with WS. Material and methods. A retrospective record review was conducted for five children who underwent CI in our department between 1993 and 2004. Results. Children with WS comprised 1.9% of our entire pediatric CI population: four girls had a familial history of WS and the phenotype of WS Type I, and one boy met the criteria for WS Type II. They were all diagnosed as having bilateral profound sensorineural hearing loss 4–24 weeks after birth. Rehabilitation was initiated immediately and included bilateral fitting of hearing aids and intensive speech and language therapy. Otoscopic and temporal bone high-resolution CT findings were normal in all patients. At surgery, all children were found to have a patent cochlea, and the electrodes were implanted into the scala tympani without difficulty. After 1.3–10.2 years of implant use all children achieved open-set recognition of 2-syllable words, with an average score of 81%. Four of the 5 children achieved open-set recognition of monosyllabic words (average score 40%) and 3 achieved open-set recognition of words in sentences (average score 81%).     

Cochlear implantation in superficial siderosis

Superficial siderosis (SS) of the central nervous system has been thought to be a rare condition that generates progressive hearing loss, ataxia, pyramidal signs, and dementia. The main cause of hearing loss by SS is thought to be neuronal. Because there is no histopathologic report of the human temporal bone in SS, there is a debate about the possibility of cochlear involvement. We present a 25-year-old man who was investigated for bilateral progressive sensorineural hearing loss and vestibular failure after head trauma. On brain MRI, SS of the central nervous system was detected. Distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) showed no response on both sides. However, integrity of the eighth nerve was proved by the electrical ABR test on the right side and the patient benefited significantly from cochlear implantation. The sensorineural hearing loss in SS seems to be related to cochlear damage as well as neuronal damage. So, cochlear implantation would be a hearing rehabilitation modality for the sensorineural hearing loss caused by SS.     

疑难病例人工耳蜗植入

人工耳蜗植入(CI)是重度、极重度感音神经性聋患者恢复听力的最成功及有效方式,其中疑难病例CI手术主要包括两类,一类是手术难度及风险较高者,另一类是术前耳聋病因不明确、诊断较为困难,术后疗效不佳或不确定者,结合相关文献介绍处理上述各类情况的临床经验。     

Cochlear implantation in cochlear otosclerosis

OBJECTIVES/HYPOTHESIS: The objective was to correlate implant performance in cochlear otosclerosis to 1) matched control samples, 2) severity of otic capsule involvement, 3) prior ipsilateral surgery, and 4) programming issues. STUDY DESIGN: Retrospective case controlled study. METHODS: Study cohort comprised 30 individuals. Diagnosis was based on prior ear surgery (stapedectomy [n = 18] or fenestration [n = 2]) and/or pathognomonic radiological findings. High-resolution computed tomography images of the temporal bones were assessed by two radiologists and graded (range, 0-3) for the extent of otosclerosis. Operative records were reviewed. Performance, programming visits, and the number of electrode deactivations at 6 months and at 1 year after implantation were determined for the individuals with otosclerosis and compared with a group of matched control subjects. A within-group comparison correlating severity of otosclerosis to the above was carried out. RESULTS: Implant performance in individuals with cochlear otosclerosis was not significantly different from those without. Previous surgery on the side of implantation did not alter performance. Programming difficulty as reflected in the number of visits and electrode deactivation for sound quality reasons were comparable. Deactivation for facial nerve stimulation occurred exclusively in otosclerotics with the most severe radiological disease (grade 3) and was only with non-modiolar hugging electrodes (n = 5). There was no observed difference between the radiological extent of otosclerosis and implant performance. CONCLUSION: Individuals with severe otosclerosis considering cochlear implantation can be counseled to expect similar benefit to those without, regardless of whether prior surgery occurred on the side of implantation or of severity of otic capsule involvement. There is a significant risk of facial nerve stimulation in otosclerotics with grade 3 disease.     

CHARGE综合征人工耳蜗植入

目的 CHARGE综合征表现为一系列临床症状,包括:眼组织病变(C)、心脏疾病(H)、后鼻孔闭锁(A)、生长与发育延迟和/或中枢神经系统异常(R)、生殖系统发育不良(G),以及耳部异常和/或耳聋(E)。该病是一种罕见的、通常散发的、常染色体显性遗传的疾病,三分之二的病例由于CHD7基因突变引起。对于出现极重度感音神经性耳聋(SNHL)的该病患者,人工耳蜗植入(CI)对于听力和语言的疗效在文献报道中存在较大差异。本文总结了三例CHARGE综合征患者CI的疗效,并对相关文献进行回顾。方法三例诊断为CHARGE综合征的极重度SNHL患者,在我科接受CI,在常规术前检查外,对其CHD7基因进行测序。术后随访三年,对其听觉反应和言语发育进行监测。结果三例患者均成功完成CI,两例患者查出CHD7基因突变。耳部严重畸形的患者,手术难度较大。术后随访3年,一例患者有听力改善,但无言语发育;一例患者既无听觉反应,亦无言语发育;另一例患者听力明显改善,言语发育良好。结论患有极重度SNHL的CHARGE综合征患者,CI可能改善听觉反应和言语发育,但其转归并不总是理想的。对于耳部畸形的患者,手术难度较大。     

Cochlear implantation in developing countries

A cochlear implant program was started in Jeddah, Saudi Arabia, in September 1983. Three totally deaf adult patients have received implants so far, with encouraging results. The problems of cochlear implantation in developing countries are discussed with regard to the patient, team, and device. The rationale, stages, and future of the program are outlined.     

伴有听力障碍的多残儿童人工耳蜗疗效分析

目的 探讨多残儿童人工耳蜗植入手术的经验及问题。方法 我院近年来开展多导人工耳蜗植入术600余例，对其中8名多残儿童开展了多导人工耳蜗植入手术。8名患者中，深度感音性聋同时合并智障与脑瘫者1例，余合并智障者2例，其中一例智障患者合并Mondini畸形，合并脑瘫者3例，Usher’s综合症2例。对这8例患者进行回顾性分析，随访3～5年。就术后开机调试特点，术后听力言语康复效果以及存在的问题等进行讨论。结果 （1）术后无面瘫、脑脊液漏、脑膜炎等手术并发症；（2）手术后护理比常规人工耳蜗术后病人复杂：病人哭闹、卧床困难、输液困难、不配合医护人员工作等；（3）开机调试后所有术后多残儿童都有听觉反应，除1例听到声音后极为恐惧外，其余患者都非常兴奋，但调试比较困难，患者配合程度差，有时一个病人需要多次调试才能获得结果，增加了调机人员的工作难度；（4）经过艰苦的康复训练，言语辨别率比术前明显提高，家长对此很满意。结论 伴有多种残疾的深度感音性聋患者可以行人工耳蜗植入，术后增加了一个全新的康复手段，从而为整个康复计划起到了推动作用，减轻了患者家庭和社会的负担，但增加了医护人员术后护理、调机以及康复上的工作难度。     

Cochlear implantation in Pendred syndrome

Abstract

Objective

The objective of this study was to examine the anatomical, audiological, and surgical factors that can affect the hearing outcome in Pendred syndrome cochlear implant recipients. Patients with Pendred syndrome represent challenging cochlear implant candidates, combining goiter, severe-to-profound hearing loss, and inner-ear dysplasias. The hearing outcome and further relevant parameters in such patients have not been adequately evaluated yet.

Material and methods

Retrospective study in a tertiary referral cochlear implant centre. Data of patients with Pendred syndrome, who had undergone cochlear implantation in the 10-year period 1999–2008, were evaluated.

Results

Five cochlear implant recipients with Pendred syndrome were identified, four unilateral and one bilateral. The average postoperative follow-up duration for these patients was 4.8 years. Enlarged vestibular aqueduct and Mondini dysplasia were the most common anatomical findings. Although these anatomical variances did not affect the electrode insertion, they prolonged the duration of the surgery. Cerebrospinal fluid gusher was the most common intraoperative complication. All patients enjoyed satisfactory hearing rehabilitation.

Discussion

Cochlear implantation is the proper method for optimal hearing rehabilitation in patients with Pendred syndrome. Although the precise pathogenetic mechanism and the genetic background of deafness in Pendred syndrome have not been completely understood, the preexisting hearing experience represents a positive factor for satisfying hearing outcome. The inner-ear malformations can cause mild surgical difficulties and extended surgery duration. The cochlear implant surgeon should be aware of these difficulties to avoid complications.     

Cochlear implantation in child.

Implants in children of the Nucleus 22-channel system have recently been approved in the United States by the Food and Drug Administration (FDA). Several questions still remains, however, concerning patient selection. This paper presents a statistical method of reporting results and its application to two populations of cochlear implant candidates: congenitally deaf children, and profoundly deaf children with meningitis as the cause of their deafness. It has been suggested that as these two groups may have significantly lower performance than other populations, it may not be appropriate to select them as implant candidates. The statistical method used aggregated single-subject, repeated measures data to reach conclusions on performance. Findings for congenitally deaf subjects evidenced significant improvements over preoperative performance. Results for post-meningitic children showed no significant difference in overall performance compared to non-meningitic children.     

Cochlear implantation in deaf infants

OBJECTIVES: With the application of universal newborn hearing screening programs, a large pool of newly identified deaf infants has been identified. The benefits of early intervention with cochlear implants (CI) is being explored. Mounting evidence suggests that age at implantation is a strong predictor of language outcomes. However, new behavioral procedures are needed to measure speech and language skills during infancy. Also, procedures are needed to analyze the speech input to young CI recipients. STUDY DESIGN: Cohort-sequential. METHODS: Thirteen infants with profound hearing loss who were implanted between the ages of 6 to 12 months of age participated in this study. Eight participated in two new behavioral methodologies: 1) the visual habituation procedure to assess their discrimination of speech sounds; 2) the preferential looking paradigm to assess their ability to learn associations between speech sounds and objects. Older implanted infants and normal-hearing infants were also tested for comparison. The pitch of mothers' speech to infants was analyzed. RESULTS: Patterns of looking times for the very early implanted infants were similar to those of normal hearing infants. Mothers' speech to infants with CIs was similar in pitch to normal-hearing infants who had the same duration of experience with sounds. CONCLUSIONS: No surgical or anesthetic complications occurred in this group of infants, and the pattern of listening skill development mirrors that seen in normal-hearing infants. Mothers adjust their speech to suit the listening experience of their infants.     

Cochlear implantation in otosclerosis.

OBJECTIVE: The purpose of this study was to evaluate and compare the results obtained in a group of implanted otosclerotic patients with a group of cochlear implant (CI) patients not affected by otosclerosis. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Nine patients affected by profound sensorineural hearing loss caused by otosclerosis and nine patients affected by profound sensorineural hearing loss not caused by otosclerosis were evaluated. INTERVENTION: Cochlear implantation. MAIN OUTCOME MEASURES: Preoperative imaging, intraoperative findings, postoperative facial nerve stimulation, and speech perception performance measures were performed and the data analyzed. RESULTS: Otosclerosis patients showed signs of cochlear ossification both on high-resolution computed tomography scans and intraoperatively. The incidence of facial nerve stimulation was higher in the otosclerosis group, three out of nine, and was generally related to the use of electrical stimulation from the Nucleus 22 cochlear implant. Psychophysical and speech perception measures did not show significant differences between the two groups, despite some otosclerosis patients showing increased electrical thresholds and comfort levels and slightly poorer speech perception performance scores. CONCLUSIONS: Patients with otosclerosis who have progressed to profound hearing loss derive significant benefit from cochlear implants; however, an increased risk of cochlear ossification and facial nerve stimulation has to be taken in account during preoperative counseling. The advance in imaging techniques, CI technology and the possibility to stimulate precise regions of the cochlea with lower intensities make it possible for the surgeons and audiologists to readily and successfully manage these complications as they arise.     

Cochlear implantation in Waardenburg's syndrome

CONCLUSIONS: Children with Waardenburg's syndrome (WS) derive significant benefit from cochlear implantation (CI) and do so to an extent that is comparable to that of the general population of implanted children. Although we report on a relatively small cohort, our data are useful for counseling the parents of children with WS considering CI. OBJECTIVE: To present our experience with CI in patients with WS. MATERIAL AND METHODS: A retrospective record review was conducted for five children who underwent CI in our department between 1993 and 2004. RESULTS: Children with WS comprised 1.9% of our entire pediatric CI population: four girls had a familial history of WS and the phenotype of WS Type I, and one boy met the criteria for WS Type II. They were all diagnosed as having bilateral profound sensorineural hearing loss 4-24 weeks after birth. Rehabilitation was initiated immediately and included bilateral fitting of hearing aids and intensive speech and language therapy. Otoscopic and temporal bone high-resolution CT findings were normal in all patients. At surgery, all children were found to have a patent cochlea, and the electrodes were implanted into the scala tympani without difficulty. After 1.3-10.2 years of implant use all children achieved open-set recognition of 2-syllable words, with an average score of 81%. Four of the 5 children achieved open-set recognition of monosyllabic words (average score 40%) and 3 achieved open-set recognition of words in sentences (average score 81%).     

Cochlear implantation in Mondini dysplasia

The use of cochlear implantation to treat patients with inner ear malformations such as Mondini dysplasia has been increasingly successful. Until now, conventional hearing aids in these patients have not performed well. Consequently, the hearing problem for patients with this condition has been somewhat improved with the use of cochlear implants. Various results of cochlear implantation have been reported in these patients so far. This is a report of 5 patients with Mondini malformation who have undergone cochlear implant surgery.