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Biomedical subjects

E Truy

Publications and source records attributed to E Truy.

At least 19 recordsLinked to original sources
PubMed2006

[Revision ossiculoplasty: anatomical and functional results].

OBJECTIVES: To analyse the anatomical and functional results after second-look ossiculoplasty using Titanium (TI) and Hydroxyapatite (HA) prosthesis and to study the prognostic factors for good functional results. PATIENTS AND METHODS: Forty nine patients (19 men and 30 women) with an average age of 36 years were included in this study. The patients presented with anatomical and/or functional failures after a first ossiculoplasty and had a second-look intervention. The status of the first prosthesis and also the anatomical status of the middle ear and the remaining ossicular chain were described intra operatively. The functional and anatomical results were assessed 2 months after the second ossiculoplasty and during the most recent out patient clinic. Postoperative air conduction gain (ACG) and air bone gap (ABG) were calculated in average values using four frequencies: 0.5, 1, 2 and 4 kHz. The variables used in statistical analysis were the following: Tympanic membrane and preoperative middle ear status, the type of prosthesis (partial or total) and its material (TI and HA). RESULTS: The average time to second-look operation was 18 months. The postoperative ABG did not show any significant statistic improvement and in several patients auditory function deteriorated in the operated ear The predictive factors for good functional results were: The integrity of the tympanic membrane, chronic otitis media without cholesteatoma, total prosthesis and HA prosthesis. If three of these factors were present, the postoperative ABG would always be less than 20 dB. CONCLUSION: When selecting patients for second look ossibuloplasty it is important to understand the predictive facctors for good results. This will allow a full discussion of options, risks and morbidity with the patient.

Adolescent↗
PubMed2005

Normative findings of electrically evoked compound action potential measurements using the neural response telemetry of the Nucleus CI24M cochlear implant system.

One hundred and forty-seven adult recipients of the Nucleus 24 cochlear implant system, from 13 different European countries, were tested using neural response telemetry to measure the electrically evoked compound action potential (ECAP), according to a standardised postoperative measurement procedure. Recordings were obtained in 96% of these subjects with this standardised procedure. The group results are presented in terms of peak amplitude and latency, slope of the amplitude growth function and ECAP threshold. The effects of aetiological factors and the duration of deafness on the ECAP were also studied. While large intersubject variability and intrasubject variability (across electrodes) were found, results fell within a consistent pattern and a normative range of peak amplitudes and latencies was established. The aetiological factors had little effect on the ECAP characteristics. However, age affected ECAP amplitude and slope of the amplitude growth function significantly; i.e., the amplitude is higher in the lowest age category (15-30 years). Principal component analysis of the ECAP thresholds shows that the thresholds across 5 electrodes can be described by two factors accounting for 92% of the total variance. The two factors represent the overall level of the threshold profiles ('shift') and their slopes across the electrode array ('tilt'). Correlation between these two factors and the same factors describing the T- and C-levels appeared to be moderate, in the range of 0.5-0.6.

Action Potentials↗
PubMed2005

[Auditory neuropathy: clinical presentation of seven cases and review of the literature].

INTRODUCTION: Auditory Neuropathy (AN) is defined as a sensorineural hearing loss characterized by normal cochlear haircell function (assessed by recordable Otoacoustic Emissions) and absent or abnormal auditory brainstem evoked potentials (ABR) corroborated with absence of middle ear reflexes. PATIENTS AND METHODS: We report five cases with AN. We also report two others cases in which the presentation was different but suggestive of AN. For the majority of patients, the hearing loss had been detected during childhood. Hearing assessment of these patients included appropriate behavioral audiometric techniques (Pure Tone Audiometry - PTA, and speech audiometry), objective measures of middle ear function, acoustic reflex studies, Otoacoustic Emissions (OAE) and Auditory Brainstem Responses (ABR). RESULTS: Pure tone audiometry revealed mild-to-profound hearing loss. In patients with recordable PTA thresholds were less degraded than speech intelligibility. In all patients, tympanogram and OtoAcoustic Emissions were normal. The stapedius reflex and Auditory Brainstem Responses were absent or very degraded. CONCLUSIONS: AN can be diagnosed by the combined use of pure tone audiometry, speech audiometry, and objectives measures with the recording of OAE and ABR responses. Neonatal hearing loss OAE screening can miss babies with AN. The sooner the diagnosis is established the more successful the treatment, new opportunities being afforded by cochlear implantation.

Adult↗
PubMed2004

A longitudinal study on postoperative hearing thresholds with the Vibrant Soundbridge device.

The Vibrant Soundbridge is a semi-implantable middle ear hearing device used in the rehabilitation of adults with sensorineural hearing loss. In order to evaluate the long-term effects of the implanted part of the device, audiological data from 39 patients implanted over several implant sites across France were collected and analyzed retrospectively. The mean follow-up time was 16 months; 25 patients had a follow-up period of over 1 year. Surgery was uneventful in all cases. The present study of the 39 implanted patients with a mid- to long-term follow-up found a statistically significant modification of hearing thresholds (pre- versus postoperative) for frequencies of 0.5 and 4 kHz. However, the shift of threshold was rather limited (2.79 and 3.34 dB, respectively), and this variation was not statistically different from the evolution of the opposite non-operated ear.

Adult↗
PubMed2002

Auditory late cortical response and speech recognition in Digisonic cochlear implant users.

OBJECTIVE: The purpose of the study was to test for differences in late electrically evoked auditory potentials between subjects exhibiting "good" versus "poor" speech recognition performances with their cochlear implants. METHODS: Late auditory evoked responses were measured in 30 subjects equipped with the Digisonic (MXM, Antibes, France) cochlear implant, 15 of whom had "good" speech recognition scores (i.e., more than 89% correct phoneme identification without lip reading). The 15 other subjects had poorer speech recognition scores (i.e., less than 85%). RESULTS: Differences in N1P2 amplitude, as well as P1, N1, and P2 latencies, and N1-P1 and N1-P2 latency intervals were tested. Wave P2 latency was found to be significantly different between the two groups (P =.016), being shorter in "good" than in "poor" performers. The strength of the statistical relationship between electrophysiological and speech recognition variables (r2 = 17%) was substantially smaller than that observed using electrically evoked auditory brainstem response (EABR) for the same implanted device (r2 = 49% for the EABR wave III-V latency interval). CONCLUSIONS: Some characteristics of late electrically evoked auditory potentials differ significantly among cochlear implant users depending on their speech recognition performance. However, the relationship between electrophysiological and speech recognition variables is more pronounced when early (brainstem) rather than late (cortical) evoked responses are considered.

Adult↗
PubMed2002

[Binaural cochlear implantation: general concept, surgical technique and electrophysiology].

Cochlear implant have been proven to be safe and cost-effective in deafened adults. Generally, a single cochlear implants is proposed providing monaural audition. Some teams have published interesting results in patients wearing two cochlear implants. The cost of the surgical procedure is greatly increased for bilateral implantation. In an attempt to provide patients with binaural hearing and a better chance to improve their capacity for frequency discrimination without an excessive increase in cost, we developed an new concept and design for binaural cochlear implants. The aim of the present study was to establish the surgical technique for binaural cochlear implantation with a single internal receptor-stimulator. We report descriptive data on surgical procedures performed in two cadavers and in two deafened adults. The special implant is composed of a single receptor-stimulator and two electrode arrays: a short one implanted into the ipsilateral ear and a long one in the contralateral ear. A specially designed tool for endoscopic facial lifting was used to create subcutaneous tunnels from the ipsilateral to the contralateral ear. Insertion into cochleas was unremarkable. Additional time for surgery (compared with mean operative time for routine adult surgery in our unit), and surgical details are discussed. Binaural cochlear implantation is feasible, easy and not very time consuming. Studies are in progress to determine patient benefit. Obtaining auditory brainstem evoked potentials electrically in patients with binaural cochlear implants is possible and provides an interesting mode for in vivo analysis of the long-term effect of profound/total deafness on neural transmission. In our patients, results have demonstrated that neural response properties in auditory pathways are negatively related to duration of deafness.

Adult↗
PubMed2001

Relationship between NRT measurements and behavioral levels in children with the Nucleus 24 cochlear implant may change over time: preliminary report.

OBJECTIVE: Response from spiral ganglion cells to electrical stimulation via the Nucleus 24 cochlear implant can be measured using the neural response telemetry system. The purpose of this study was to assess, in children, the correlation between the neural response threshold and the behavioral levels used for cochlear implant programming process. METHODS: The neural response telemetry test was administered to 23 children (mean age at implantation: 4 years) with the Nucleus 24 cochlear implant. Four intra-cochlear electrodes (electrodes 5, 10, 15 and 20) were tested. The neural response threshold at 3, 6, 9 and 12 months post-implantation was compared with the behavioral threshold and the maximum comfort level estimated during the same periods: a Pearson's correlation test was performed for each tested electrode. RESULTS: On apical electrodes, the correlation with the behavioral threshold remained significant from 3 to 12 months post-implantation (r ranging from 0.696 to 0.909, P<0.05), and the correlation with the maximum comfort level was also significant throughout the study period, except on electrode 15 at 9 months (tendency to significance). On basal and intermediate electrodes, statistical correlations were found only at some points of time; nonetheless, at 12 months post-implantation, a significant correlation with behavioral levels could be clearly demonstrated both on electrode 15 (r=0.914--0.778, P<0.05) and on electrode 10 (r=0.845--0.720, P<0.05). CONCLUSIONS: This preliminary study suggests that the correlation between the neural response threshold and behavioral levels may improve from the base towards the apex of the cochlea. However, a significant correlation can be demonstrated for all tested electrodes at 12 months post-implantation. During the first months post-implantation care must be exercised when interpreting neural response telemetry measurements: a positive test does not necessarily mean that the stimulus delivered to the acoustic nerve will be centrally processed with the result of an auditory perception.

Action Potentials↗
PubMed2001

Cross-modal plasticity underpins language recovery after cochlear implantation.

Postlingually deaf subjects learn the meaning of sounds after cochlear implantation by forming new associations between sounds and their sources. Implants generate coarse frequency responses, preventing place-coding fine enough to discriminate sounds with similar temporal characteristics, e.g., buck/duck. This limitation imposes a dependency on visual cues, e.g., lipreading. We hypothesized that cross-modal facilitation results from engagement of the visual cortex by purely auditory tasks. In four functional neuroimaging experiments, we show recruitment of early visual cortex (V1/V2) when cochlear implant users listen to sounds with eyes closed. Activity in visual cortex evolved in a stimulus-specific manner as a function of time from implantation reflecting experience-dependent adaptations in the postimplant phase.

Acoustic Stimulation↗
PubMed2001

[Genetic deafness:the primary cause of sensorineural hearing loss in children].

Genetically-transferred hearing impairments account for more than 50% of cases of pediatric sensorineural hearing defects. Multiple clinical aspects are involved in genetic hearing impairment, including the involvement of other organs, genetic inheritance, and the degree and age at onset of hearing loss. Diagnosis relies on family history, on the systematic investigation of the symptomatology including an associated syndrome, and audiometry testing in parents and siblings. Analysis of the connexin 26 gene is also indicated, as it is frequently involved in this disorder. Further genetic analysis in affected families will aid in detecting other as yet unidentified genes responsible for hearing impairment.

Age of Onset↗
PubMed2001

A multicenter study of the Vibrant Soundbridge middle ear implant: early clinical results and experience.

OBJECTIVE: The Vibrant Soundbridge (VBS; Symphonix Devices, Inc., San Jose, CA, U.S.A.) is an active, semi-implantable, middle ear hearing device that directly drives the ossicular chain and is used in the treatment of patients with mild to severe sensorineural hearing loss. The benefits of the VBS and the effects of surgery were examined and compared with the preoperative aided condition in 25 patients with implants. STUDY DESIGN: Single-subject repeated-measures evaluations were performed with each patient acting as his or her own control. Objective audiologic measures and subjective questionnaires also were used. SETTING: Five tertiary referral and teaching hospitals. SUBJECTS: Adult patients had bilateral sensorineural hearing loss (average hearing loss, 56 dB; range, 33-80 dB). Twenty-one patients had worn a conventional hearing aid before surgery (11 binaurally, 10 monaurally). Four patients had not used a conventional hearing aid before surgery. INTERVENTION: Rehabilitative. RESULTS: No significant change in residual hearing after surgery was observed. Functional gain was significantly superior with the VBS. No significant differences were observed for aided speech recognition in quiet. A significant improvement in communication in various listening conditions was reported with the VBS as compared with conventional hearing aids. CONCLUSION: The VBS surgical implantation procedure does not affect the residual hearing level in the implanted ear, nor does it present any unacceptable risk. Measurable benefit from the VBS in comparison with conventional amplification was demonstrated with regard to the provision of superior usable amplification and greater ease in communication in daily listening environments for the majority of patients.

Acoustic Stimulation↗
PubMed2000

[Hearing impairment in children: early diagnosis is essential].

Diagnosis of hearing impairment is possible during the first days of life. Hearing tests are noninvasive and should not be delayed when hearing loss is suspected. Among children's hearing impairments, conductive hearing loss is the most frequent; it is generally acquired and reversible. At the opposite pole, sensorineural hearing loss has more severe consequences because it is irreversible and often present from birth. Early diagnosis and treatment are necessary in all cases to prevent speech delay. In cases with sensorineural hearing impairment, hearing aid fitting, or even cochlear implantation, and intensive speech therapy will help deaf children learn speech, with the view of optimal social and professional integration.

Age of Onset↗
PubMed2000

Differential recruitment of the speech processing system in healthy subjects and rehabilitated cochlear implant patients.

Differences in cerebral activation between control subjects and post-lingually deaf rehabilitated cochlear implant patients were identified with PET under various speech conditions of different linguistic complexity. Despite almost similar performance in patients and controls, different brain activation patterns were elicited. In patients, an attentional network including prefrontal and parietal modality-aspecific attentional regions and subcortical auditory regions was over-activated irrespective of the nature of the speech stimuli and during expectancy of speech stimuli. A left temporoparietal semantic region was responsive to meaningless stimuli (vowels). In response to meaningful stimuli (words, sentences, story), left middle and inferior temporal semantic regions and posterior superior temporal phonological regions were under-activated in patients, whereas anterior superior temporal phonological regions were over-activated. These differences in the recruitment of the speech comprehension system reflect the alternative neural strategies that permit speech comprehension after cochlear implantation.

Acoustic Stimulation↗
PubMed1999

Neuro-functional imaging and profound deafness.

This paper deals with the subject of the place of neuro-functional imaging in cochlear implantation. Neuro-functional imaging is a means to assess the functioning of the brain in some normal or pathological conditions. Deafness is a model of sensorineural deprivation. Cochlear implantation offers to clinicians and neuroscientists a model for understanding influence of deafness on cerebral connectivity, and to assess mechanisms of plasticity when the auditory inputs are given again to a deaf cochlea. This paper proposes a brief review of the literature on cochlear implantation and neuro-functional imaging. Patients can be scanned pre- or post-operatively, thus different questions can be investigated about neurobiology of the consequences of deafness and auditory rehabilitation by cochlear implantation, and about the possible role of neuro-functional imaging in cochlear implant candidates to predict the future benefit of the implantation.

Auditory Cortex↗
PubMed1999

Evaluation of cochlear implanted children's voices.

Cochlear implant (CI) is a good means in developing communication in deaf children. Nevertheless, compared to children with the same age, CI patients' voices are far from being similar. In this work, the voice of CI children has been compared with the voice of corresponding normal children (same age, same sex) included in the main stream. Six girls and two boys participated to the experiment. The phonetic material was a paragraph of the French standard text La bise et le soleil (The North Wind and the Sun). An objective and a subjective analysis of the voice were done and parameters were compared between both groups of people (implantees and control). Studied parameters were voice pitch, intensity, fluency, pauses, articulation and pleasantness in the objective analysis, and voice pitch, formants, and duration for the objective study. It appeared that intensity variations were different between control and implanted subjects. Also voice formants were not situated in the same region regarding the normal ranges, but differences were difficult to assess. Globally, the main change was in the speaking duration. This method is open for further studies and points out some relevant items for an efficient use in rehabilitation sessions.

Adolescent↗