Didier Bouccara

Speech Performance and Sound Localization in a Complex Noisy Environment in Bilaterally Implanted Adult Patients

Objective: To evaluate speech performance, in quiet and noise, and localization ability in adult patients who had undergone bilateral and simultaneous implantation. Study Design: Prospective multi-center study. Methods: Twenty-seven adult patients with profound or total hearing loss were bilaterally implanted in a single-stage procedure, and simultaneously activated (Med-El, Combi 40/40+). Subjects were assessed before implantation and at 3, 6 and 12 months after switch-on. Speech perception tests in monaural and binaural conditions were performed in quiet and in noise using disyllabic words, with speech coming from the front and a cocktail party background noise coming from 5 loudspeakers. Sound localization measurements were also performed in background noise coming from 5 loudspeakers positioned from –90° to +90° azimuth in the horizontal plane, and using a speech stimulus. Results: There was a bilateral advantage at 12 months in quiet (77 ± 5.0% in bilateral condition, 67 ± 5.3% for the better ear, p < 0.005) and in noise (signal-to-noise ratio +15 dB: 63 ± 5.9% in bilateral condition, 55 ± 6.9% for the better ear, p < 0.05). Considering unilateral speech scores recorded in quiet at 12 months, subjects were categorized as ‘good performers’ (speech comprehension score ≥60% for the better ear, n = 19) and ‘poor performers’ (n = 8). Subjects were also categorized as ‘asymmetrical’ (difference between their 2 unilateral speech scores ≥20%, n = 11) or ‘symmetrical’ (n = 16). The largest advantage (bilateral compared to the better ear) was obtained in poor performers: +19% compared to +7% in good performers (p < 0.05). In the group of good performers, there was a bilateral advantage only in cases of symmetrical results between the 2 ears (n = 10). In the group of poor performers, the bilateral advantage was shown in both patients with symmetrical (n = 6) and asymmetrical results (n = 2). In bilateral conditions, the sound localization ability in noise was improved compared to monaural conditions in patients with symmetrical and asymmetrical performance between the 2 ears. No preoperative factor (age, duration of deafness, use of hearing aids, etiology, etc.) could predict the asymmetrical performance, nor which ear would be the best. Conclusion: This study demonstrates a bilateral advantage (at 12 months after the implantation) in speech intelligibility and sound localization in a complex noisy environment. In quiet, this bilateral advantage is shown in cases of poor performance of both ears, and in cases of good performance with symmetrical results between the 2 ears. No preoperative factor can predict the best candidates for a simultaneous bilateral implantation.

Benefits of cochlear implantation in elderly patients

Cochlear implantation in elderly patients is a questionable subject. The purpose of this study was to evaluate the procedure and its outcome, the postoperative course, and the audiologic and social benefits of cochlear implantation in this population. Twenty-seven patients older than 60 years were compared with a control group of 15 adult patients. This retrospective study analyzed data concerning the outcome of the procedure, postoperative course, postoperative orthophonic test results, and answers of a questionnaire assessing the changes in communication, perception, and social outcomes. The procedure was uneventful in both groups. Minor complications were not more frequent in elderly patients. Orthophonic test results were comparable in both groups. At 12 months, 83% of the elderly patients had an open-set speech discrimination score above 60%. The benefits of cochlear implantation in terms of the quality of life are not statistically different with younger patients. Cost-utility analysis might support these findings.

Auditory brainstem implant in neurofibromatosis type 2 and non-neurofibromatosis type 2 patients.

Objective: To evaluate the auditory brainstem implant (ABI) performances in neurofibromatosis type 2 (NF2) and non-NF2 patients. Study Design: Retrospective cohort study. Setting: Tertiary referral center. Patients: Between 1996 and 2006, 31 adult patients (mean age, 41 yr; range, 17-65 yr) were implanted with a 21-electrode Nucleus device (Cochlear Inc., Lane Cove, Australia). The population comprised 23 NF2, 3 postmeningitis bilateral ossified cochleas, 3 solitary vestibular schwannomas on the only hearing ear, 1 inner ear malformation, and 1 bilateral cochlear destruction by otosclerosis. Intervention: Auditory brainstem implant was placed through a translabyrinthine or a retrosigmoid approach. Main Outcome Measures: Auditory brainstem implant was evaluated by open-set words and sentences in sound, vision, and sound-plus-vision modes. Results: In NF2 patients, 16 (70%) were daily users of their implants. In these patients, the open-set dissyllabic word recognition was 36 ± 6.0 % for vision-only mode, 33 ± 6.5 % for sound-only mode, and 65 ± 8.0 % in vision-plus-sound mode with a high interindividual variation. Negative prognostic factors were long duration of total hearing loss (>10 yr), low number of active electrodes (<10), and local complications (meningitis, hematoma). Six non-NF2 patients (75%) were daily ABI users. The performances of patients with ossified cochleas were similar to best NF2 cases. Conclusion: A clear benefit of ABI could be evidenced in NF2 patients, especially in case of small tumor and short duration of hearing loss. Auditory brainstem implant may also be indicated in patients with bilateral profound hearing loss and a predictable failure of cochlear implantation.

Evaluation of the Management of Postoperative Aseptic Meningitis

BACKGROUND A consensus conference recommended empirical antibiotic therapy for all patients with postoperative meningitis and treatment withdrawal after 48 or 72 h if cerebrospinal fluid culture results are negative. However, this approach is not universally accepted and has not been assessed in clinical trials. METHODS We performed a cohort study of all patients who received a diagnosis of postoperative meningitis from January 1998 through May 2005 in a teaching hospital. From January 1998 through September 2003 (control period), guidelines were lacking or were not implemented. From October 2003 through May 2005 (interventional period), all patients received a predefined intravenous antibiotic therapy that was discontinued on the third day if the meningitis was considered aseptic. Clinical outcome and duration of antibiotic therapy were analyzed for each patient. RESULTS Seventy-five episodes of postoperative meningitis (21 cases of bacterial meningitis and 54 cases of aseptic meningitis) were investigated. Patients with aseptic meningitis received antibiotic treatment for a mean +/- standard deviation duration of 11+/-5 days during the control period and 3.5+/-2 days during the intervention period (P=.001). The duration of antibiotic treatment for bacterial meningitis was not significantly different between the 2 periods. All episodes of bacterial and aseptic meningitis were cured, and complications were rare during both periods. CONCLUSIONS Stopping antibiotic treatment after 3 days is effective and safe for patients with postoperative meningitis whose cerebrospinal fluid culture results are negative.

Cochlear Implant Benefits in Deafness Rehabilitation: PET Study of Temporal Voice Activations

Cochlear implants may improve the medical and social prognosis of profound deafness. Nevertheless, some patients have experienced poor results without any clear explanations. One correlate may be an alteration in cortical voice processing. To test this hypothesis, we studied the activation of human temporal voice areas (TVA) using a well-standardized PET paradigm adapted from previous functional MRI (fMRI) studies. Methods: A PET H215O activation study was performed on 3 groups of adult volunteers: normal-hearing control subjects (n = 6) and cochlear-implanted postlingually deaf patients with >2 y of cochlear implant experience, with intelligibility scores in the “Lafon monosyllabic task” >80% (GOOD group; n = 6) or <20% (POOR group; n = 6). Relative cerebral blood flow was measured in 3 conditions: rest, passive listening to human voice, and nonvoice stimuli. Results: Compared with silence, the activations induced by nonvoice stimuli were bilaterally located in the superior temporal regions in all groups. However these activations were significantly and similarly reduced in both cochlear implant groups, whereas control subjects showed supplementary activations. Compared with nonvoice, the voice stimuli induced bilateral activation of the TVA along the superior temporal sulcus (STS) in both the control and the GOOD groups. In contrast, these activations were not detected in the POOR group, which showed only left unilateral middle STS activation. Conclusion: These results suggest that PET is an adequate method to explore cochlear implant benefits and that this benefit could be linked to the activation of the TVA.

Large deletion of the GJB6 gene in deaf patients heterozygous for the GJB2 gene mutation: Genotypic and phenotypic analysis

Recent investigations identified a large deletion of the GJB6 gene in trans to a mutation of GJB2 in deaf patients. We looked for GJB2 mutations and GJB6 deletions in 255 French patients presenting with a phenotype compatible with DFNB1. 32% of the patients had biallelic GJB2 mutations and 6% were a heterozygous for a GJB2 mutation and a GJB6 deletion. Biallelic GJB2 mutations and combined GJB2/GJB6 anomalies were more frequent in profoundly deaf children. Based on these results, we are now assessing GJB6 deletion status in cases of prelingual hearing loss.

Diagnosis and management of intracochlear schwannomas.

Objective: To describe and analyze a series of intracochlear schwannomas. Methods: From 1987 to 2005, 19 patients with schwannomas involving the cochlea were included in this series. Clinical, audiovestibular, and imaging data concerning initial and follow-up visits were collected. Results: The mean age was 54 years (range, 25-71 yr). The series comprised 10 women and 9 men, 18 solitary tumors and 1 neurofibromatosis Type 2 patient. The mean diagnosis delay was 11 years (range, 1-31 yr). At diagnosis, a total or profound hearing loss (Class D of American Academy of Otolaryngology-Head and Neck Surgery classification) was noted in 17 patients (89%), and a severe loss (Class C) was reported in 2 patients (11%). Facial paresis was reported in 2 patients (11%; Grades 2 and 4 of House and Brackmann classification). Magnetic resonance imaging showed an involvement of the posterior labyrinth in 8 patients (37%), an extension of the schwannoma to the internal auditory meatus in 8 patients (37%), and a cerebellopontine angle extension in 7 patients (32%). In 11 patients (58%), the schwannoma was removed through a transotic route. In the 8 remaining patients, a watch-and-rescan policy was decided. The postoperative course was uneventful. Postoperative follow-up period was 27 months (range, 6-88 mo). Postoperative facial function was assessed as Grade 1 in 7 patients, as Grade 2 in 4, and as Grade 4 in 1 patient. Conclusion: The diagnosis of intracochlear schwannomas can be difficult on magnetic resonance imaging. The diagnosis should be considered in all unilateral hearing losses.

Auditory Brainstem Implantation to Rehabilitate Profound Hearing Loss with Totally Ossified Cochleae Induced by Pneumococcal Meningitis

Hearing rehabilitation by cochlear implantation is not always possible in case of total ossification after pneumococcal meningitis. We report 3 cases of postmeningitis profound hearing loss with total cochlear ossification in adults who underwent auditory brainstem implantation (Nucleus 22®, Cochlear Inc., Lane Cove, Australia) between 1999 and 2004. The postoperative follow-up period ranged from 1 to 6 years. Eleven to 15 out of 22 electrodes were activated. All patients had significant speech discrimination in the sound-only mode and an enhanced lip-reading performance with the implant. Auditory brainstem implants are an efficient means of auditory rehabilitation and may be considered in selected cases of bilateral profound hearing loss with the impossibility of cochlear implantation.

Inner Ear Pressure in Menière's Disease and Fluctuating Hearing Loss Determined by Tympanic Membrane Displacement Analysis

Menières disease and fluctuating hearing loss are related to labyrinthine fluid pressure variations. The development of a new indirect method of analysis of the tympanic membrane displacement during the stapedial reflex, using the Marchbanks Measurements System (MMS 10), allows us to study inner ear fluid pressure during these pathological conditions. In this study, measurements with this method were made in four groups of patients: a control group with normal hearing (n=7), stable sensorineural hearing loss (n=9), fluctuating hearing loss (n=8), and Menières disease (n=25). Results show, first, a good relationship between the recording of negative curves, suggesting a high pressure, and the acute episodes of fluctuating hearing loss; and, secondly, in the case of Menières disease two types of situation: positive and negative curves suggesting normal and high pressures, respectively.

Diode laser in otosclerosis surgery: first clinical results.

Objective: To evaluate the functional results of otosclerosis surgery using diode laser. Study Design: Retrospective cohort analysis. Patients: One hundred seven patients operated on for otosclerosis with a diode laser (119 ears, all primary cases) and 141 patients operated on with a conventional technique (141 ears, all primary cases). Revision cases using the diode laser were also described. Methods: Preoperative tomographic computed scan findings and intraoperative observations were collected. Pure-tone and vocal audiometry was performed preoperatively and postoperatively (at 3 mo and 1 yr). Results: In the laser group, the air-bone gap was 29 ± 0.8 dB (n= 112) preoperatively and 9 ± 0.6 dB (n = 58) at 1 year. Air conduction was improved by 22 ± 1.7 dB at 1 year (n = 58). In the conventional group, the air-bone gap was 32 ± 0.9 dB (n=127) preoperatively and 10 ± 0.6 dB (n = 127) at 1 year. Air conduction was improved by 25 ± 1.1 dB (n = 127) at 1 year. No difference of hearing gain was observed between the 2 groups at 1 year. A decreased rate of footplate fracture was observed with the diode laser (3.6%) compared with the conventional technique (21.3%). Conclusion: Diode laser is a reliable and safe device for otosclerosis surgery. The functional results were similar to those reported in other series.