Liliana Colletti

Cochlear Implantation at under 12 months: Report on 10 Patients†

Objectives: There is growing evidence that early application of a cochlear implant in children affected by profound congenital hearing loss is of paramount importance for the development of an adequate auditory performance and language skills. For these reasons and as a result of advances in audiologic diagnosis and an enhanced awareness of the safety of cochlear implants, the age of implantation has substantially decreased over recent years. Children aged as little as 12 months are now being implanted in some centers. On the basis of our experience with very young children, we believe that the date of implantation may be further reduced to only 4 to 6 months of age.

Auditory brainstem implant (ABI): new frontiers in adults and children.

Previous studies have considered only patients with neurofibromatosis type 2 (NF2) older than 12 years as candidates for an auditory brainstem implant (ABI). Our study expands the potential criteria to include both children and adult subjects with other cochlear or cochlear nerve malfunctions who either would not benefit at all from a cochlear implant (eg, cochlear nerve aplasia or avulsion) or whose benefit was or would be severely compromised (eg, cochlear ossification, cochlear fracture). STUDY DESIGN: In our department, over the period from April 1997 to September 2002, 29 patients, 20 adults and 9 children, were fitted with ABIs. Their ages ranged from 14 months to 70 years. Thirteen subjects had tumors, 10 NF2 and 3 solitary vestibular schwannoma, and 16 patients had a variety of nontumor (NT) cochlear or cochlear nerve diseases. A retrosigmoid-transmeatal approach was used in T and a retrosigmoid approach in NT patients. The electrode array was inserted into the lateral recess of the fourth ventricle and correct electrode positioning was monitored with the aid of electrically evoked auditory brainstem responses (EABRs). RESULTS: Correct implantation was achieved in all patients. No complications were observed due to implantation surgery or related to ABI activation or long-term use. Auditory sensations were induced in all patients with various numbers of electrodes (from 5 to 15). Different pitch sensations were identifiable with different electrode stimulation. Closed-set word recognition, open-set sentence recognition, and speech tracking scores achieved by the patients are reported in detail. The auditory performance of the patients showed significantly better outcomes than controls (Multicentric European clinical investigations on ABI with NF2). CONCLUSION: We have shown that the indications for the ABI can be extended to include NT patients with severe cochlear and/or cochlear nerve abnormalities. The degree of auditory benefit varies as a function of the underlying pathological conditions, with NT subjects exhibiting significantly better outcomes than the T patients.

Outcomes in nontumor adults fitted with the auditory brainstem implant: 10 years' experience.

Objectives: Recently, open-set speech recognition performance has been observed with electric stimulation of the brainstem in some nontumor (NT) patients. These outcomes require that we reevaluate the criteria for patient selection and the rationale for expanding the application for the auditory brainstem implant (ABI) to NT adult patients with profound hearing loss. This study presents results from up to 10 years in adults, with analysis based on cause. Materials and Methods: In our Department, from April 1997 to September 2007, ABIs have been implanted in 112 patients (83 adults and 29 children) with tumor (T) and NT disorders. Of the 112 patients, 15 have previously had a cochlear implant elsewhere with no sound detection. This article presents speech recognition results from the 80 patients (32 neurofibromatosis type 2 and 48 NT) who had achieved at least 1-year follow-up. The retrosigmoid approach was used in all NT patients, and the retrosigmoid-transmeatal approach was used in all T patients. Results: All patients had a functioning implantation, and no complications were observed during the operation, activation, or long-term use of the ABI. At the most recent follow-up, NT adults scored from 10 to 100% in open-set speech perception tests (average, 59%), and T patients scored from 5 to 31% (average, 10%). The differences between these results are statistically significant (p = 0.0007). The best performance was observed in patients who lost their nerve VIII from head trauma or severe ossification. Lowest performance (although still highly beneficial to the patient) was observed in patients with neurologic disorders, neuropathy, and cochlear malformations. Conclusion: Our experience clearly indicates that the ABI is an effective tool for hearing rehabilitation in patients with profound hearing loss who cannot be fitted with cochlear implants.

Infants versus older children fitted with cochlear implants: performance over 10 years.

OBJECTIVES To investigate the efficacy of cochlear implants (CIs) in infants versus children operated at later age in term of spoken language skills and cognitive performances. METHOD The present prospective cohort study focuses on 19 children fitted with CIs between 2 and 11 months (X=6.4 months; SD=2.8 months). The results were compared with two groups of children implanted at 12-23 and 24-35 months. Auditory abilities were evaluated up to 10 years of CI use with: Category of Auditory Performance (CAP); Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS); Peabody Picture Vocabulary Test (PPVT-R); Test of Reception of Grammar (TROG) and Speech Intelligibility Rating (SIR). Cognitive evaluation was performed using selected subclasses from the Griffiths Mental Development Scale (GMDS, 0-8 years of age) and Leiter International Performance Scale-Revised (LIPS-R, 8-13 years of age). RESULTS The infant group showed significantly better results at the CAP than the older children from 12 months to 36 months after surgery (p<.05). Infants PPVT-R outcomes did not differ significantly from normal hearing children, whereas the older age groups never reached the values of normal hearing peers even after 10 years of CI use. TROG outcomes showed that infants developed significantly better grammar skills at 5 and 10 years of follow up (p<.001). Scores for the more complex subtests of the GMDS and LIPS-R were significantly higher in youngest age group (p<.05). CONCLUSION This study demonstrates improved auditory, speech language and cognitive performances in children implanted below 12 months of age compared to children implanted later.

Auditory brainstem implant as a salvage treatment after unsuccessful cochlear implantation.

Objective: The present article investigates on an individual basis the performance achieved with the auditory brainstem implant in patients who had been treated unsuccessfully with a cochlear implant. Study Design: An intrasubject comparison between results achieved with the cochlear implant and the auditory brainstem implant is reported. Setting: Tertiary referral care. Patients: Five subjects were fitted with an auditory brainstem implant in our department because of the poor results achieved with cochlear implants. Two were children, one with bilateral cochlear nerve aplasia and one suffering from auditory neuropathy. Three were adults with complete cochlear ossification. Intervention: A retrosigmoid approach was used in all subjects. Electrically evoked auditory brainstem responses and neural response telemetry were used to monitor electrode positioning. Results: No complications were observed due to implantation surgery or related to activation or long-term use of the auditory brainstem implant. Auditory sensations were induced in all patients with varying numbers of electrodes (from 9–16). In all three adults, the cochlear implant did not allow either word/sentence discrimination or speech tracking, whereas the auditory brainstem implant permitted discrimination of two- or three-syllable words with scores from 85 to 100%. In the two adults with a follow-up of 5 and 6 months after auditory brainstem implant activation, the open-set sentence recognition scores (auditory-only mode) were 70% and 100%, respectively, and the speech-tracking scores were 27 and 40 words/min, respectively. One patient with a follow-up of only 3 months scored 0% in both sentence recognition and speech tracking. The two children who had achieved no hearing ability with the cochlear implant were already able to detect sounds and words as early as 2 months after activation of the auditory brainstem implant and are showing progressive improvement in their performance. Conclusion: Auditory brainstem implantation may be a very powerful rehabilitative treatment after cochlear implant failure. The possibility of using the auditory brainstem implant as first-choice therapy in some categories of deaf patients (e.g., subjects with auditory neuropathy or cochlear ossification) who are currently treated with cochlear implantation is discussed.

Long-term follow-up of infants (4–11 months) fitted with cochlear implants

Conclusion: In this study the outcomes from several indices (Category of Auditory Performance, CAP; Peabody Picture Vocabulary Test (Revised), PPVT-R; Test of Reception of Grammar, TROG; and Speech Intellegibility Rating, SIR) in three groups of children with different ages at implantation (from 4 to 36 months) with a follow-up time from 4 to 9 years demonstrate that very early cochlear implantation (<11 months) provides normalization of audio-phonologic parameters with no complications. Objectives: The aim of the present study was to investigate the efficacy of cochlear implants (CIs) in infants who were implanted at < 11 months of age versus children operated at later age (i.e. 12–36 months) and to document whether children who receive a CI below 11 months of age are able to achieve age-appropriate expected spoken language skills, at a follow-up time from 4 to 9 years. Subjects and methods: From November 1998 to November 2007, 185 children received CIs and 34 received auditory brainstem implants in our department. The present study focuses on 13 children implanted at ages younger than 12 months (4–11 months; mean, 8.2; SD = 2.4) and fitted with CIs between November 1998 and March 2004. To avoid bias these children were selected from a larger longitudinal cohort of pediatric CI recipients fitted with CIs because they all were implanted with the same cochlear device (Nucleus CI 24 M) during the same period. Postoperatively auditory abilities were evaluated at the latest follow-up, from 4 to 9 years after surgery, with CAP, PPVT-R, TROG, and SIR. The results obtained in this group of 13 children were compared with those obtained in two groups of children implanted at later ages (12–23 and 24–36 months, respectively). Results: No complication has been observed so far. The highest score of CAP function was achieved in all the three groups but at different intervals from CI activation as function of age at CI implantation. The rate of receptive language growth (PPVT-R) provides distinctive evidence that only the scores of the first group overlap the line of normal-hearing children, whereas the second and third group never reached the values of normal peers even after 9 years of CI use. TROG outcomes clearly indicate that only children from the first group (77%) are in the 76–100 percentile at 5 years follow-up. At 9 years follow-up, 100% of children in the first group, 38% in the second group, and 20% in the third group are in the 76–100 percentile. The SIR outcomes at the 5 years follow-up indicate that none of children was identified within the first two categories, only children from the third group (18%) were identified in category 3, all infants of the first group, 80% of group 2, and 63% of the third group were identified in category 5. At the 9 years follow-up, the number of children from the third group identified in category 3 was reduced to 10%, the second and third groups displayed a slightly higher percentage of children in category 5, but the difference from the values observed at the 5-year follow-up is not significant.

Auditory Brainstem Implant in Posttraumatic Cochlear Nerve Avulsion

Patients aged over 12 years with neurofibromatosis type 2 are considered candidates for an auditory brainstem implant (ABI). This study extends the indication criteria of ABI to subjects with profound hearing loss due to damaged cochleas and/or cochlear nerves (CNs) following head injuries. In our department, over the period from April 1997 to November 2002, 32 patients, 23 adults and 9 children, were fitted with ABIs. Their ages ranged from 14 months to 70 years. These patients were suffering from a variety of tumor (13 subjects) and nontumor CN or cochlear diseases (19 subjects). Six patients, 5 adults and 1 child, had profound hearing loss following head injury. Their mean age was 25 years (range: 16–48 years). Five were male and 1 female. The retrosigmoid approach was used in all 6 patients. The electrode array was inserted into the lateral recess of the fourth ventricle and correct electrode positioning was monitored with the aid of electrically evoked auditory brainstem responses and neural response telemetry. Correct implantation was achieved in all patients. No complications were observed due to implantation surgery or related to ABI activation and stimulation of the cochlear nuclei. At activation, an average of 9.8 electrodes (range 5–13) were switched on without side effects. One to 6 electrodes were activated in the following sessions after time periods ranging from 2 to 16 months. All patients achieved auditory-alone-mode closed-set word recognition scores ranging from 40 to 100%; 3 had auditory-alone-mode open-set sentence recognition scores of 60–100%; 2 of these even had speech-tracking performance scores of 38 and 43 words, respectively, showing an ability to engage in normal conversation and converse over the phone. The present study demonstrates that the ABI is a useful rehabilitation instrument in subjects with damaged cochleas and/or CN avulsion following head injury who are unamenable or poorly responsive to auditory rehabilitation using cochlear implants.

TORP vs round window implant for hearing restoration of patients with extensive ossicular chain defect

Conclusions: Round window implant (RWI) with a floating mass transducer (FMT) may be suggested as the first choice in hearing rehabilitation for patients with chronic otitis media (COM) and extensive destruction of the ossicular chain. Objective: To investigate the pros and cons of the total ossicular replacement prosthesis (TORP) vs the RWI in restoration of hearing in patients with COM. Patients and methods: Thirty-eight patients with bilateral moderate to severe mixed or conductive hearing loss from COM without cholesteatoma and bilateral ossicular chain erosion (footplate residual) were alternately assigned to a titanium-TORP (T-TORP) and to RWI with the FMT of the Medel Vibrant Soundbridge (MVBS) located onto the RW niche. The therapeutic efficiency, preoperative vs postoperative air-conduction gain and speech recognition were investigated for the two groups and statistically analyzed at 36 months postoperatively. The following postoperative anatomic conditions were also evaluated for the two groups: 1) recurrence of infection, 2) retraction pocket, 3) extrusion rate, and 4) displacement of the prosthesis. Results: Good functional results and stability at 36 months were obtained with both procedures. The extrusion rates for T-TORP were low. So far no extrusion has been observed for RWI. Hearing results were statistically much better for RWI vs T-TORP for all investigated parameters.

Nonverbal Cognitive Abilities and Auditory Performance in Children Fitted With Auditory Brainstem Implants: Preliminary Report†

Objectives/Hypothesis: Auditory brainstem implants (ABIs) can provide excellent open set speech recognition in adults without auditory tumors. These favorable results prompted us to extend ABI indications to children with profound hearing loss (HL) who are not candidates for a cochlear implant (CI). This article reports on the auditory performance and cognitive development measured in children with ABIs.

Auditory results after vestibular nerve section and intratympanic gentamicin for Ménière's disease.

Objective: Hearing loss is a possible complication of vestibular neurectomy and intratympanic gentamicin administration in Ménières disease. The aim of this study was to compare the incidence of this complication with the two treatments. Study Design: Retrospective review. Setting: Tertiary referral center. Patients: The initial study population reviewed consisted of 24 patients receiving gentamicin injections and 209 patients undergoing vestibular nerve section. Comparison of data was performed among all 24 intratympanic gentamicin patients and the last 24 vestibular neurectomy patients operated on via the retrosigmoid approach. Interventions: Intratympanic gentamicin administration (26-156 mg) and retrosigmoid vestibular neurectomy. Main Outcome Measure: Auditory and vertigo results were evaluated according to the American Academy of Otolaryngology 1995 criteria. Results: The mean preoperative pure-tone average for patients undergoing vestibular nerve section was 48.5 dB, with a speech discrimination score of 85%. In these patients, the postoperative pure-tone average was 50.3 dB, and the speech discrimination score was 82%. Patients undergoing gentamicin injection had a mean pretreatment pure-tone average of 50.1 dB and a speech discrimination score of 87%. The posttreatment pure-tone average and discrimination score for the gentamicin group were 74.7 dB and 65%, respectively. The amount of postprocedure hearing loss was significantly greater in the gentamicin group (p = 0.03). Excellent control of vertigo (classes A and B) was obtained in 95.8% of the patients treated with vestibular nerve section and in 75% of the patients in the gentamicin group. Conclusion: Gentamicin administration and vestibular neurectomy are both effective for relieving vertigo in Ménières disease. The incidence of hearing loss is significantly higher after gentamicin injection.