Isabelle Mosnier

Factors Affecting Auditory Performance of Postlinguistically Deaf Adults Using Cochlear Implants: An Update with 2251 Patients

Objective: To update a 15-year-old study of 800 postlinguistically deaf adult patients showing how duration of severe to profound hearing loss, age at cochlear implantation (CI), age at onset of severe to profound hearing loss, etiology and CI experience affected CI outcome. Study Design: Retrospective multicenter study. Methods: Data from 2251 adult patients implanted since 2003 in 15 international centers were collected and speech scores in quiet were converted to percentile ranks to remove differences between centers. Results: The negative effect of long duration of severe to profound hearing loss was less important in the new data than in 1996; the effects of age at CI and age at onset of severe to profound hearing loss were delayed until older ages; etiology had a smaller effect, and the effect of CI experience was greater with a steeper learning curve. Patients with longer durations of severe to profound hearing loss were less likely to improve with CI experience than patients with shorter duration of severe to profound hearing loss. Conclusions: The factors that were relevant in 1996 were still relevant in 2011, although their relative importance had changed. Relaxed patient selection criteria, improved clinical management of hearing loss, modifications of surgical practice, and improved devices may explain the differences.

Cardiovascular and Thromboembolic Risk Factors in Idiopathic Sudden Sensorineural Hearing Loss: A Case-Control Study

Objective: The pathogenesis of idiopathic sudden sensorineural hearing loss (ISSHL) remains unknown, but vascular involvement is one of the main hypotheses. The main objective of this study was to investigate the association between ISSHL and cardiovascular and thromboembolic risk factors. Study Design: Multicentric case-control study. Methods: Ninety-six Caucasian patients with ISSHL and 179 sex- and age-matched controls were included. Patients were evaluated on the day of the inclusion and 1 week, 3 weeks and 3 months later. Clinical information concerning personal and familial cardiovascular and thromboembolic risk factors and concerning the ISSHL was collected. Blood samples were collected for genetic analysis of factor V Leiden and G20210A polymorphism in the factor II gene. The severity of the hearing loss was classified as mild (21–40 dB), moderate (41–70 dB), severe (71–90 dB) and profound or total (>90 dB). Hearing improvement was calculated as a relative improvement of hearing thresholds using the contralateral ear as baseline. Results: Systolic blood pressure was higher in patients (130 ± 1.7 mm Hg) than in controls (124 ± 1.1 mm Hg, p = 0.003). The personal/familial history of cardiovascular events was also more prevalent in patients (p = 0.023 and p = 0.014, respectively), whereas no difference was found in the prevalence of personal cardiovascular risk factors (hypertension, diabetes mellitus, hyperlipidemia, smoking habits). There was no correlation between the audiogram type, the hearing outcome and the presence of cardiovascular risk factors. No significant difference was observed in the personal/familial history or in the presence of thromboembolic risk factors. The prothrombin and factor V mutations were uncommon in both patients and controls. The final hearing threshold was only correlated with the severity of the initial hearing loss (p < 0.001), but not influenced by the presence of vertigo, audiogram type, time elapsed from onset of ISSHL to hospitalization or failure of a previous oral therapy. Hearing stabilization was obtained at 21 days in 92% of patients. Conclusion: These results support the theory of vascular involvement as the etiology of some cases of ISSHL. The sole predictive factor of poor final hearing is the severity of the initial hearing loss.

Improvement of cognitive function after cochlear implantation in elderly patients

IMPORTANCE The association between hearing impairment and cognitive decline has been established; however, the effect of cochlear implantation on cognition in profoundly deaf elderly patients is not known. OBJECTIVE To analyze the relationship between cognitive function and hearing restoration with a cochlear implant in elderly patients. DESIGN, SETTING, AND PARTICIPANTS Prospective longitudinal study performed in 10 tertiary referral centers between September 1, 2006, and June 30, 2009. The participants included 94 patients aged 65 to 85 years with profound, postlingual hearing loss who were evaluated before, 6 months after, and 12 months after cochlear implantation. INTERVENTIONS Cochlear implantation and aural rehabilitation program. MAIN OUTCOMES AND MEASURES Speech perception was measured using disyllabic word recognition tests in quiet and in noise settings. Cognitive function was assessed using a battery of 6 tests evaluating attention, memory, orientation, executive function, mental flexibility, and fluency (Mini-Mental State Examination, 5-word test, clock-drawing test, verbal fluency test, d2 test of attention, and Trail Making test parts A and B). Quality of life and depression were evaluated using the Nijmegen Cochlear Implant Questionnaire and the Geriatric Depression Scale-4. RESULTS Cochlear implantation led to improvements in speech perception in quiet and in noise (at 6 months: in quiet, 42% score increase [95% CI, 35%-49%; P < .001]; in noise, at signal to noise ratio [SNR] +15 dB, 44% [95% CI, 36%-52%, P < .001], at SNR +10 dB, 37% [95% CI 30%-44%; P < .001], and at SNR +5 dB, 27% [95% CI, 20%-33%; P < .001]), quality of life, and Geriatric Depression Scale-4 scores (76% of patients gave responses indicating no depression at 12 months after implantation vs 59% before implantation; P = .02). Before cochlear implantation, 44% of the patients (40 of 91) had abnormal scores on 2 or 3 of 6 cognition tests. One year after implant, 81% of the subgroup (30 of 37) showed improved global cognitive function (no or 1 abnormal test score). Improved mean scores in all cognitive domains were observed as early as 6 months after cochlear implantation. Cognitive performance remained stable in the remaining 19% of the participants (7 of 37). Among patients with the best cognitive performance before implantation (ie, no or 1 abnormal cognitive test score), 24% (12 of 50) displayed a slight decline in cognitive performance. Multivariate analysis to examine the association between cognitive abilities before implantation and the variability in cochlear implant outcomes demonstrated a significant effect only between long-term memory and speech perception in noise at 12 months (SNR +15 dB, P = .01; SNR +10 dB, P < .001; and SNR +5 dB, P = .02). CONCLUSIONS AND RELEVANCE Rehabilitation of hearing communication through cochlear implantation in elderly patients results in improvements in speech perception and cognitive abilities and positively influences their social activity and quality of life. Further research is needed to assess the long-term effect of cochlear implantation on cognitive decline.

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.

Management of cholesterol granulomas of the petrous apex based on clinical and radiologic evaluation.

Objective The purpose of this study was to analyze the imaging characteristics of 12 cholesterol granulomas as a function of their clinical symptoms. The results of the different surgical approaches and the management of these lesions are discussed. Study Design Retrospective case review. Setting Five tertiary referral centers. Patients Twelve patients managed for a cholesterol granuloma of the petrous apex. Interventions All patients were evaluated via computed tomography and magnetic resonance imaging. Eight patients required surgical drainage: through a conservative approach in seven patients (infralabyrinthine, n = 5; infracochlear, n = 2) and a transotic approach in one patient. Clinical and radiologic follow-up without surgery was the mode of treatment for four patients. The mean follow-up period was 18 months for patients who underwent operations and ranged from 6 months to 10 years for patients without operations. Results Four patterns of clinical symptoms were noted: retrocochlear signs by an involvement of the internal auditory meatus (n = 8), headaches by a traction of the dura (n = 4), serous otitis media by a compression of the eustachian tube (n = 2), and asymptomatic lesions with no involvement of the adjacent structures (n = 2). Hearing and facial functions were preserved in all the cases treated by a noninvasive procedure. No recurrence or complication was reported in the patients who underwent operations. None of the noninvasively treated patients with cholesterol granulomas showed significant enlargement on follow-up imaging. Conclusion Clinical manifestations of cholesterol granulomas depend on their anatomic location and the involvement of the adjacent structures. Aggressive lesions in patients with residual hearing can be drained via an infralabyrinthine or an infracochlear approach with minimal morbidity. Follow-up must be preferred for patients with nonaggressive lesions. Although magnetic resonance imaging provides a specific diagnosis tool for cholesterol granulomas, computed tomography is essential for an accurate evaluation of the location of the cyst and choice of the surgical procedure.

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.

Cochlear implants in elderly people: Preliminary results

The objective of this study was to evaluate the benefit of cochlear implantation in adults aged 60 years and over. Twenty-eight patients, older than 60 years and with profound bilateral sensorineural hearing loss, received a cochlear implant between 1991 and 2001. The mean age was 66 years and the median follow-up was 22.5 months. Speech perception scores before and after implantation were analyzed retrospectively in order to evaluate the benefit of cochlear implantation. There was a significant improvement of the disyllabic words and sentences scores after implantation. The patients who were over 70 years performed as well as those who were younger. The surgical procedure was well tolerated in all patients. One patient developed a postoperative vertigo due to a perilymphatic fistula. In conclusion, cochlear implantation offers improvement in speech perception to the elderly population, as in the younger population. A careful assessment of the physical status of these patients remains essential in order to evaluate the risk–benefit of this procedure.

Intraoperative laryngeal nerve monitoring during thyroidectomy and parathyroidectomy: A prospective study

OBJECTIVES The aim of this study was to stimulate the recurrent laryngeal nerve during thyroidectomy or parathyroidectomy and to record the muscle responses in an attempt to predict postoperative vocal fold mobility. PATIENTS AND METHODS Intraoperative recurrent laryngeal nerve monitoring during general anaesthesia was performed by using an electrode-bearing endotracheal tube (nerve integrity monitor EMG endotracheal tube [Medtronic Xomed, Jacksonville, Flo, USA]). Two hundred and fifteen recurrent laryngeal nerves from 141 patients undergoing total thyroidectomy (n=74), hemithyroidectomy (n=63), or parathyroidectomy (n=4) were prospectively monitored. In each case, the muscle potential was recorded after stimulation of the recurrent laryngeal nerve by a monopolar probe. RESULTS The nerve stimulation threshold before and after dissection that induced a muscle response of at least 100 μV ranged from 0.1 to 0.85 mA (mean 0.4 mA). The supramaximal stimulation intensity was defined as 1 mA. The amplitude of muscle response varied considerably from one patient to another, but the similarity of the muscle response at supramaximal intensity between pre- and postdissection and between postdissection at the proximal and distal exposed portions of the nerve was correlated with normal postoperative vocal fold function. Inversely, alteration of the muscle response indicated a considerable risk of recurrent laryngeal nerve palsy, but was not predictive of whether or not this lesion would be permanent. CONCLUSIONS Recurrent laryngeal nerve monitoring with a system using surface electrodes is a simple, non-invasive technique that is just as sensitive as monitoring by intramuscular electrodes. Monitoring is helpful for initial nerve identification and is useful to determine nerve function during and after surgery, and to adapt the surgical strategy accordingly.

Multicenter Evaluation of the Digisonic SP Cochlear Implant Fixation System With Titanium Screws in 156 Patients

Objectives: We describe and evaluate the process of fixation of the Digisonic SP cochlear implant with two titanium screws. Methods: The characteristics of this implant allow cochlear implantation using a minimal incision, a subperiosteal pocket, and fixation with two titanium screws, without drilling a custom-fitted seat or creating suture-retaining holes in the skull. The fixation system relies on two tailfins for use of osseo-integratable screws, incorporated into the cochlear implant housing. The first version of this fixation system was modified after a case of device migration: The size of the titanium insert inside the silicone tailfin was increased. Data on 156 patients (8 months to 86 years of age) from a 4-year period in 6 cochlear implantation centers were retrospectively evaluated. Ten patients have undergone bilateral implantation. Results: Of 166 implantations, 4 postoperative infections and 1 device failure after head trauma were reported. No cerebrospinal fluid leaks or epidural hematomas were reported. One device migration was observed in the first series; no device migrations occurred in the second series. Conclusions: The fixation system with screws embedded in the Digisonic SP involves a fast and simple surgical technique that seems to efficiently prevent implant migration.

Effects of acute and chronic hypertension on the labyrinthine barriers in rat.

Hearing loss, vertigo, and tinnitus have been related to arterial hypertension. The aim of the present work was to study the permeability of the blood-perilymph and of the labyrinthine barrier, between endolymph and perilymph, to small molecules during chronic and acute hypertension. Experiments were performed in normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Acute hypertension was induced by phenylephrine. Perilymph was sampled from the first turn of the scala vestibuli and the Na, K, urea, and radioactive concentrations ((14)C-urea and (3)H-mannitol) were measured. In another experimental set, the endocochlear potential was recorded from the basal turn of scala media, before and after phenylephrine injection. The composition of the perilymph and the kinetic constants for (14)C-urea and (3)H-mannitol were similar in WKY and SHR, and not modified after acute hypertension. In endolymph, the endocochlear potential in SHR (+80+/-2.7 mV, n=24) was lower (P<0.001) than in WKY (+98+/-1.5 mV, n=29). The endocochlear potential was decreased by 40 mV during acute hypertensive peak in seven out of 19 WKY but not in SHR rats (n=13). In conclusion, chronic or acute hypertension did not severely alter the permeability to small molecules of the blood-perilymph barrier. The relationship between the low endocochlear potential and hypertension in SHR remains to be evaluated. After acute hypertensive peak, the presence of vascular protective mechanisms in the cochlea could account for the stable endocochlear potential recorded in SHR and 60% of normotensive rats.