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Biomedical subjects

A Huarte

Publications and source records attributed to A Huarte.

14 recordsLinked to original sources
PubMed2005

Advantages of binaural hearing provided through bimodal stimulation via a cochlear implant and a conventional hearing aid: a 6-month comparative study.

CONCLUSIONS: Our study data demonstrate the additional benefit derived from continued use of a contralateral hearing aid (HA) post-cochlear implantation for speech recognition ability in quiet and in noise. Postoperative bimodal stimulation is recommended for all subjects who show some speech recognition ability in the contralateral ear as it may offer binaural listening advantages in various listening situations encountered in everyday life. OBJECTIVES: To assess the benefits derived from bimodal stimulation for experienced HA users implanted with a cochlear implant (CI) (score=20% in disyllabic test). The correlation between pre- and postoperative performance on speech perception measures was examined to determine additional criteria for recommending bimodal stimulation postoperatively. MATERIAL AND METHODS: A within-subject repeated-measures design was used, with each subject acting as their own control. Assessments were carried out preoperatively in aided monaural and best-aided conditions and at 6 months postoperatively in CI-alone, contralateral HA-alone and bimodal listening conditions. Speech recognition using Spanish words and sentences materials was assessed at conversational level and for soft speech in quiet. Speech comprehension in noise was assessed using word materials at a signal:noise ratio of +10, for coincident speech in noise and for spatially separated speech in noise. Twelve adult native Spanish subjects with a severe-to-profound hearing impairment who were experienced with optimally fitted conventional amplification and who displayed suboptimal speech understanding preoperatively were enrolled in the study. Preoperatively, conventional amplification was worn by five subjects binaurally and by seven monaurally. RESULTS: Postoperatively, superior speech recognition ability in quiet and in noise for disyllabic words was achieved using bimodal stimulation in comparison to performance for either monaural aided condition. Mean improvement in speech recognition in the bimodal condition was significant over performance in the CI-alone condition for disyllabic words in quiet at 70 (p=0.006) and 55 dB SPL (p=0.028), for disyllabic words in noise at +10 dB with speech and noise spatially separated with the noise source closest to the contralateral HA (S0NHA) (p=0.0005) and when the noise source was closest to the CI ear (S0NCI) (p=0.002). When testing word recognition in noise with speech and noise sources coincident in space, word scores were superior in the bimodal condition relative to the CI-alone condition but this improvement was not significant (p=0.07). The advantages of bimodal stimulation included significant effects of binaural summation in quiet and significant binaural squelch effects in both the S0NHA and S0NCI test conditions. All subjects showed superior performance in the binaural situation postoperatively relative to the best-aided condition preoperatively for one or more test situations.

Adult↗
PubMed1999

Cerebral auditory plasticity and cochlear implants.

Previous animal research and clinical experiences in humans suggest the existence of an auditory critical period in language acquisition. We review the literature and present the changes within the cochlear nuclei in bilaterally deafferentated adult non-human primates. We also present and analyse the results of 98 prelingually deaf children and teenagers who underwent a cochlear implantation at the University of Navarra. Patients received a Nucleus 22 or 24 multichannel cochlear implant (CI). They were grouped in five categories according to their age at surgery. Performance is compared with a control group of 58 postlinguals. Only early-implanted prelingual children (before 6 years of age) achieved a complete open-set speech recognition, even with better performance than postlinguals. These results clearly demonstrate the existence of a period of high neural auditory plasticity within the first 6 years of life. The introduction of auditory stimulation with a CI can not restore the loss of neural plasticity out of this period. Prelingual children under 6 years of age should receive a CI as soon as there is a reliable diagnosis of bilateral sensorineural hearing loss.

Adolescent↗
PubMed1999

[Study of surgical complications and technical failures (correction of technical defects) of cochlear implants].

INTRODUCTION: Cochlear implants (CI) have proved their clinical efficacy and have overcome a routine treatment for profound sensorineural impairment. In the present paper we review our CI program concerning surgical complications and equipment failures. MATERIAL AND METHODS: One-hundred and thirty-five patients (69 younger and 66 older than 14 years of age) are subjects of the study. They suffered from pre-lingual (86 cases) or post-lingual (49 cases) profound bilateral sensorineural hearing impairment, and all of them received a Mini Nucleus 22 CI in our CI program. We analyze minor and major surgical complications and also CI and external equipment failures. RESULTS: In 6.1% of the patients (8 cases) a surgical complication occurred, 3 of them flap-related complications. In 2 of these cases (1.54%) complications were major. Three patients (2.17%) developed a complete CI failure, while in 8 cases malfunction of one or more electrodes was detected. Cumulative survival of CI was 87 months, without significant differences related to age or gender. Cumulative survival of the processors was 78.6 months, without significant differences related to the type of processor (MSP or Spectra) or gender but related to the age. The microphone failed in 42.2% of the cases. CONCLUSIONS: The CI is a low-morbidity treatment with adequate characteristics of durability and reliability. Nevertheless, some of the external components remain quite vulnerable.

Adolescent↗
PubMed1998

Indications and counterindications for cochlear implantation in children.

OBJECTIVE: This study is aimed to analyze the current indications and counterindications of cochlear implantation (CI) in children. STUDY DESIGN: This study reviews the children implanted in our institution looking specifically at the following aspects: 1) auditory criteria for candidate selection; 2) age at implantation; 3) educational environment; and 4) associated handicapping conditions. SETTING: Tertiary referral center with experience in CI since 1989 with inpatient and outpatient care. INTERVENTION: All children received a Mini Nucleus 22 CI device (Cochlear Limited, Australia) in a standard surgical procedure. RESULTS: Regarding auditory criteria, children with average hearing level of 100-105 dB HL are more likely to obtain benefit from a CI than from a hearing aid. The minimum age for CI should be as soon as there is a reliable diagnosis of bilateral profound hearing loss, while the maximum age for CI depends on strict selection criteria of candidates. The educational environment is of a great importance in the rehabilitation process, permitting a progressive change to oral communication. Our experience in CI of children with multiple handicapping conditions is limited to a case of a deaf-blind child who was implanted with a good performance. In the selection of these children it is mandatory to have extensive multidisciplinary evaluation. CONCLUSIONS: An experienced team is needed in the selection of children for CI. Candidates should meet anatomic criteria, have a reliable diagnosis of bilateral profound hearing loss, an evaluation of communication skills, and extensive neuropediatric and socioeducational evaluation.

Adolescent↗
PubMedDate not supplied

[Hearing and speech in children under 2 years of age with a cochlear implant].

BACKGROUND: To compare the auditory abilities and speech performance of children with a profound prelingual bilateral hearing impairment, treated with a cochlear implant (CI) before or after 2 years of age. To analyze the complications arising during the selection process of the children, or as a result of the implantation, programming and follow-up. METHODS: Prospective cohort single-subject repeated-measures study of 130 children who received an implant at our center. The children were divided into two age groups: 0-2 (n=36), and 2-6 years of age (n=94). Preoperative evaluation included: 1. History, physical exploration, and ENT examination. 2. Neuropaediatric examination, family evaluation, and psychological assessment. 3. Auditory brainstem responses. 4. High resolution computed tomogram of temporal bones. 5. Counseling and informed consent. The children were evaluated prior to, and each year following, the intervention (for up to 5 years), using closed and open-set logoaudiometric tests, and speech perception tests. Speech was evaluated according to the Peabody Picture Vocabulary and Reynell general oral expression scale. RESULTS: Auditory and speech perception tests improved significantly in all children after CI, regardless of the follow-up time. The infant's performance was better in the group of early implantees. Speech tests showed that the development of children treated before 2 years of age was similar to that of normal children. No additional complications were observed when compared to CI in older children. CONCLUSIONS: When performed before 2 years of age, CI offers a quicker and better improvement of performance, with no increase in complications when compared with a later intervention.

Age Factors↗
PubMedDate not supplied

[Auditory brain stem potentials evoked by electrical stimulation of cochlear nuclei during central auditive implant setting].

INTRODUCTION: The implantation of a stimulator over the surface of the cochlear nuclei can provide a partial auditive capability to patients deaf due to a bilateral lesion of the 8th nerve. Intraoperative monitoring of short latency electrically-evoked potentials is useful to asses the correct positioning of the implant, specially when there are anatomical distortions. PATIENTS AND METHODS: Evoked potentials from two patients with type II neurofibromatosis were recorded during implantation surgery, using a blanker system to eliminate the stimulus artifact. RESULTS: In both cases, two-peak vertex-positive responses were obtained, with latencies between 0.4-0.5 and 1.2-1.4, respectively. This responses are similar to the most frequent response described. DISCUSSION: Intraoperative monitoring of electrically-evoked auditory brainstem responses is a useful technique to confirm the correct positioning of the cochlear stimulator. The study of the morphology of these responses can help to understand the mechanisms involved in the generation by the brainstem of the auditive evoked potentials. More experience on this subject is needed to establish a correlation between intraoperative results and postoperative stimulator function.

Adult↗
PubMedDate not supplied

[Results of osteointegrated prosthesis of Audiant type].

Patient selection criteria, auditory results, complications, and patient satisfaction as related to implantation of an Audiant prosthesis in 1991-1992 are analyzed. We report our experience with this late-generation prosthesis in three patients compared with an earlier model implanted.

Adult↗
PubMedDate not supplied

[Results of the cochlear transplant program of the University of Navarra].

From October 1989 to the end of 1991, 33 patients have received a Cochlear Implant Nucleus 22 Channel, that have been selected from over 150 patients that consulted the possibility of implantation. A cochlear implant program should count with a group of professionals of diverse areas, that work in coordination without losing contact with the rest of the member of the implant team. Cochlear Implant are considered an efficient technique in the treatment of profound neurosensorial deafness, in Pre and Postlinguistic patients. The results obtained have been better in the last group of patients, but results on the whole are considered satisfactory. In prelinguist there is a progressive positive tendency, therefore a longer amount of time is necessary to define the final results. The therapeutic capacity of this method of treatment is not limited only to the auditory area, but it has effect also in other fields related to communication and the integral development of the patients on whom it is applied.

Adolescent↗
PubMedDate not supplied

[Cochlear implants in post-lingual persons: results during the first five years of the clinical course].

Abundant literature is available on the results of cochlear implants in postlingual persons. Nevertheless, there are few long-term studies with a follow-up of more than 1 year. We present the outcomes of 37 postlingual patients with a 5-year follow-up period. We examined the modifications that occurred with changes in coding strategy (MPEAK-SPEAK). After activation, the coding strategy was SPEAK in 10 patients. MPEAK in 20: 7 other SPEAK had changed from MPEAK. Significant improvement (p < 0.01) was observed in all the tests in the first 6 months. Subsequent assessments revealed a constant improvement in all tests. The results were statistically significant (p < 0.05) for vowels, consonants and bisyllables. Performance with the SPEAK strategy was better than with MPEAK. These results were statistically significant for consonants (p < 0.05), monosyllables (p < 0.05) and bisyllables (p < 0.01). We concluded that the results of postlingual patients after cochlear implantation showed clear benefits of these devices in profound bilateral deafness, better results with the SPEAK coding strategy than with MPEAK and constant improvement in results, even after the first year of surgery.

Adolescent↗