E. Offeciers - Academia.edu (original) (raw)
Papers by E. Offeciers
Hearing Research, 2021
Following surgical implantation of a cochlear implant, the external processor must be programmed ... more Following surgical implantation of a cochlear implant, the external processor must be programmed individually, which is typically achieved by behavioral measurements, with the user indicating the perceived loudness between the threshold and the maximum comfort levels (MCLs). However, the stapedius reflex measurement could be used instead, as the basis for programming the fitting maps. The electrically evoked stapedius reflex threshold is known to have a high correlation with the MCLs and thus is used as an objective tool to determine the MCL, especially in children and non-cooperative patients. Previous studies demonstrated that the electromyogenic (EMG) activity of the stapedius muscle could be measured to determine stapedius reflex responses. The objective of this study was to demonstrate that intraoperative EMG recordings from the stapedius muscle could be performed with an EMG recording electrode designed for chronical implantation. Ten adult subjects with single sided deafness (SSD) participated in this study. The study was split up into a pre-, intra- and postoperative phase. In the preoperative phase the subjects were screened for the presence of the acoustic stapedius reflex by using a standard tympanometer in the ear to be implanted, while the contralateral ear was stimulated acoustically. During the intraoperative phase an EMG recording electrode was placed in the stapedius muscle and EMG responses were recorded during acoustical and electrical stimulation. The surgical procedure consisted of two interconnected procedures: A classical surgical approach for cochlear implantation with two additional surgical steps, and the temporary placement of an EMG recording electrode in the stapedius muscle made through an opening in the pyramidal eminence, allowing EMG recordings. The postoperative phase was used to evaluate the preservation of the stapedius reflex postoperatively at 1- and 6-months with contralateral acoustic and ipsilateral electrical stimulation. The EMG recording electrode could successfully be placed in the stapedius muscle in all subjects and was able to reliably record EMG signals from the stapedius muscle elicited by acoustic and electrical stimulation. Overall, EMG recordings were obtained intraoperatively in all subjects tested (8 out of 8 subjects). Contralateral acoustic stapedius reflexes were obtained in 6 out of 8 subjects and ipsilateral electrical stapedius reflex in 7 out of 8 subjects. In the postoperative phase, the preservation of the postoperative reflex was observed in 6 out of 10 subjects 1-month after surgery and in 8 out of 10 subjects 6-months after surgery. The study showed that intraoperative EMG recordings from the stapedius muscle can be performed with an EMG recording electrode designed for chronical implantation. The minimally invasive procedure is promising; in particular with regard to the future perspective of measurements in the long-term with an integrated closed-loop self-fitting system.
Journal of the American Academy of Audiology, 2020
Background Fitting cochlear implants in babies and noncooperative patients is cumbersome and time... more Background Fitting cochlear implants in babies and noncooperative patients is cumbersome and time consuming. Therefore, objective parameters have been sought in order to predict the subjective threshold (T) and maximum comfort (C) levels. Measurements of the electrically evoked compound action potentials (ECAPs) have been widely used for this purpose, yet the correlation between these objective measures and the subjective T/C levels is weak to moderate. Purpose This article aims (1) to evaluate correlations between the subjective parameters of the fitting maps such as thresholds (T level) and maximum comfort levels (C level), the impedance of the electrode contacts, and the ECAP thresholds, and (2) to compare the value of the electrode impedances and the ECAP measures for prediction of the T/C levels. Research Design Case review study in a quaternary otologic referral center. Study Sample Ninety-eight consecutive CI patients were enrolled. The average age of the patients was 49 year...
International Journal of Audiology, 2010
Laryngo-Rhino-Otologie, 2017
Acta oto-rhino-laryngologica Belgica, 1985
The authors describe the characteristics and specific advantages of their 8 channel bipolar intra... more The authors describe the characteristics and specific advantages of their 8 channel bipolar intrascalar stimulator, its main asset being flexibility. They emphasize the need for caution in the use of cochlear implants in children.
TM cochlear implant electrode. The electrode contacts of the TRACE electrode have the same active... more TM cochlear implant electrode. The electrode contacts of the TRACE electrode have the same active surface area for stimulation, but the position in the scala tympani is different from that of the Nucleus Contour electrode. Material and Methods */The following parameters, used in cochlear implant fitting and evaluation procedures, were determined: the threshold and comfort stimulation current levels; the electrode impedances; and the phoneme discrimination and speech recognition scores using the ACE TM speech algorithm. Results Conclusion */The new electrode does not differ significantly from the standard Nucleus Contour electrode in terms of the investigated parameters within the test group.
Introduction and aim: Vocal process granulomas (VPG) are benign lesions of the posterior glottis ... more Introduction and aim: Vocal process granulomas (VPG) are benign lesions of the posterior glottis seen over the vocal processes of the arytenoid cartilages. In the past, three major etiologies of VPG have been identified, being laryngopharyngeal reflux, intubation and phonotrauma. Some cases however have shown to be multifactorial and therefore do not respond to one particular therapy. The aim of this paper is to discuss the variety of presentation and the often unpredictable course of treatment as seen in our own clinical practice.
Acta oto-rhino-laryngologica Belgica, 1988
Acta oto-rhino-laryngologica Belgica, 1989
Five cases of tuberculosis otitis media are reported. The clinical picture and the hazards of dia... more Five cases of tuberculosis otitis media are reported. The clinical picture and the hazards of diagnosis are discussed. Although not a common cause of chronic otitis media, tuberculosis of the middle ear cleft is an entity one should recognize especially when a chronic suppurative ear disease does not respond to the usual treatment. The signs and symptoms are non-specific. Altering features include racial predisposition, contact or personal history of past or present tuberculosis, chronicity, development of a facial palsy and the pale granulation tissue found at the operation.
The American Journal of Human Genetics, 2001
Acta Oto-Laryngologica, 1996
The literature on neonatal hearing screening by means of oto-acoustic emissions (OAE's) p... more The literature on neonatal hearing screening by means of oto-acoustic emissions (OAE's) presents various prevalence figures, and gives little quantitative information on the procedure used to score the recordings. If the OAE test is to be interpreted by users who do not have the opportunity to develop intuitive interpretation skills through extensive training, a clear numerical decision criterion is needed. The present paper discusses the scoring procedure used by 25 teams, which together screen 22,356 neonates annually. More than 60% of the groups involved in this study use visual interpretation of the recorded OAE response, together with numerical criteria. Amongst the teams, 21 different ways of numerical scoring are used. It is shown that for a given set of OAE recordings, prevalence varies from 61% to 90%, depending on the numerical decision criterion being applied. We conclude that at this moment no consensus exists regarding the numerical criterion to be used when assessing OAE screening results. In view of the strong effect of criteria on the outcome of OAE screening, such consensus is urgently needed, but should be based on sensitivity and specificity figures for each scoring technique.
BACKGROUND AND PURPOSE: Only a few case reports and small series of intralabyrinthine schwan-noma... more BACKGROUND AND PURPOSE: Only a few case reports and small series of intralabyrinthine schwan-nomas (ILSs) have been reported. The purpose of this study was to assess prevalence, MR charac-teristics, location, clinical management, and growth potential/patterns of ILSs in the largest series reported. MATERIALS AND METHODS: Lesion localization, MR characteristics, lesion growth, and clinical man-agement were reviewed in 52 patients diagnosed with an ILS between February 1991 and August 2007 in 2 referral centers. The number of ILSs and vestibulocochlear schwannomas in the cerebel-lopontine angle/internal auditory canal was compared to assess the prevalence. RESULTS: ILSs most frequently originate intracochlearly, are hyperintense on unenhanced T1-weighted images, enhance strongly after gadolinium administration, and are sharply circumscribed and hypointense on thin heavily T2-weighted 3D images. The scala tympani is more frequently or more extensively involved than the scala vestibuli....
Acta oto-rhino-laryngologica Belgica, 2002
The present paper reports on the results of a retrospective study using 678 Hz susceptance-conduc... more The present paper reports on the results of a retrospective study using 678 Hz susceptance-conductance tympanometry performed on abnormally high admittant middle ears. High admittance was proven to be caused by (partial) disruption or lysis of the ossicular chain. Retrospective analysis shows that 678 Hz tympanometry seems to be more accurate in the differential diagnosis of ossicular chain disruptions compared to CT-imaging of the ossicular chain (88% versus 81% correct identification respectively). Classic tympanometry using a probe frequency of 226 Hz was abnormal in only 43% of the cases.
Acta oto-rhino-laryngologica Belgica, 1986
Nature genetics, 1998
The tectorial membrane is an extracellular matrix of the inner ear that contacts the stereocilia ... more The tectorial membrane is an extracellular matrix of the inner ear that contacts the stereocilia bundles of specialized sensory hair cells. Sound induces movement of these hair cells relative to the tectorial membrane, deflects the stereocilia, and leads to fluctuations in hair-cell membrane potential, transducing sound into electrical signals. Alpha-tectorin is one of the major non-collagenous components of the tectorial membrane. Recently, the gene encoding mouse alpha-tectorin (Tecta) was mapped to a region of mouse chromosome 9, which shows evolutionary conservation with human chromosome 11q (ref. 3), where linkage was found in two families, one Belgian (DFNA12; ref. 4) and the other, Austrian (DFNA8; unpublished data), with autosomal dominant non-syndromic hearing impairment. We determined the complete sequence and the intron-exon structure of the human TECTA gene. In both families, mutation analysis revealed missense mutations which replace conserved amino-acid residues within...
Hearing Research, 2021
Following surgical implantation of a cochlear implant, the external processor must be programmed ... more Following surgical implantation of a cochlear implant, the external processor must be programmed individually, which is typically achieved by behavioral measurements, with the user indicating the perceived loudness between the threshold and the maximum comfort levels (MCLs). However, the stapedius reflex measurement could be used instead, as the basis for programming the fitting maps. The electrically evoked stapedius reflex threshold is known to have a high correlation with the MCLs and thus is used as an objective tool to determine the MCL, especially in children and non-cooperative patients. Previous studies demonstrated that the electromyogenic (EMG) activity of the stapedius muscle could be measured to determine stapedius reflex responses. The objective of this study was to demonstrate that intraoperative EMG recordings from the stapedius muscle could be performed with an EMG recording electrode designed for chronical implantation. Ten adult subjects with single sided deafness (SSD) participated in this study. The study was split up into a pre-, intra- and postoperative phase. In the preoperative phase the subjects were screened for the presence of the acoustic stapedius reflex by using a standard tympanometer in the ear to be implanted, while the contralateral ear was stimulated acoustically. During the intraoperative phase an EMG recording electrode was placed in the stapedius muscle and EMG responses were recorded during acoustical and electrical stimulation. The surgical procedure consisted of two interconnected procedures: A classical surgical approach for cochlear implantation with two additional surgical steps, and the temporary placement of an EMG recording electrode in the stapedius muscle made through an opening in the pyramidal eminence, allowing EMG recordings. The postoperative phase was used to evaluate the preservation of the stapedius reflex postoperatively at 1- and 6-months with contralateral acoustic and ipsilateral electrical stimulation. The EMG recording electrode could successfully be placed in the stapedius muscle in all subjects and was able to reliably record EMG signals from the stapedius muscle elicited by acoustic and electrical stimulation. Overall, EMG recordings were obtained intraoperatively in all subjects tested (8 out of 8 subjects). Contralateral acoustic stapedius reflexes were obtained in 6 out of 8 subjects and ipsilateral electrical stapedius reflex in 7 out of 8 subjects. In the postoperative phase, the preservation of the postoperative reflex was observed in 6 out of 10 subjects 1-month after surgery and in 8 out of 10 subjects 6-months after surgery. The study showed that intraoperative EMG recordings from the stapedius muscle can be performed with an EMG recording electrode designed for chronical implantation. The minimally invasive procedure is promising; in particular with regard to the future perspective of measurements in the long-term with an integrated closed-loop self-fitting system.
Journal of the American Academy of Audiology, 2020
Background Fitting cochlear implants in babies and noncooperative patients is cumbersome and time... more Background Fitting cochlear implants in babies and noncooperative patients is cumbersome and time consuming. Therefore, objective parameters have been sought in order to predict the subjective threshold (T) and maximum comfort (C) levels. Measurements of the electrically evoked compound action potentials (ECAPs) have been widely used for this purpose, yet the correlation between these objective measures and the subjective T/C levels is weak to moderate. Purpose This article aims (1) to evaluate correlations between the subjective parameters of the fitting maps such as thresholds (T level) and maximum comfort levels (C level), the impedance of the electrode contacts, and the ECAP thresholds, and (2) to compare the value of the electrode impedances and the ECAP measures for prediction of the T/C levels. Research Design Case review study in a quaternary otologic referral center. Study Sample Ninety-eight consecutive CI patients were enrolled. The average age of the patients was 49 year...
International Journal of Audiology, 2010
Laryngo-Rhino-Otologie, 2017
Acta oto-rhino-laryngologica Belgica, 1985
The authors describe the characteristics and specific advantages of their 8 channel bipolar intra... more The authors describe the characteristics and specific advantages of their 8 channel bipolar intrascalar stimulator, its main asset being flexibility. They emphasize the need for caution in the use of cochlear implants in children.
TM cochlear implant electrode. The electrode contacts of the TRACE electrode have the same active... more TM cochlear implant electrode. The electrode contacts of the TRACE electrode have the same active surface area for stimulation, but the position in the scala tympani is different from that of the Nucleus Contour electrode. Material and Methods */The following parameters, used in cochlear implant fitting and evaluation procedures, were determined: the threshold and comfort stimulation current levels; the electrode impedances; and the phoneme discrimination and speech recognition scores using the ACE TM speech algorithm. Results Conclusion */The new electrode does not differ significantly from the standard Nucleus Contour electrode in terms of the investigated parameters within the test group.
Introduction and aim: Vocal process granulomas (VPG) are benign lesions of the posterior glottis ... more Introduction and aim: Vocal process granulomas (VPG) are benign lesions of the posterior glottis seen over the vocal processes of the arytenoid cartilages. In the past, three major etiologies of VPG have been identified, being laryngopharyngeal reflux, intubation and phonotrauma. Some cases however have shown to be multifactorial and therefore do not respond to one particular therapy. The aim of this paper is to discuss the variety of presentation and the often unpredictable course of treatment as seen in our own clinical practice.
Acta oto-rhino-laryngologica Belgica, 1988
Acta oto-rhino-laryngologica Belgica, 1989
Five cases of tuberculosis otitis media are reported. The clinical picture and the hazards of dia... more Five cases of tuberculosis otitis media are reported. The clinical picture and the hazards of diagnosis are discussed. Although not a common cause of chronic otitis media, tuberculosis of the middle ear cleft is an entity one should recognize especially when a chronic suppurative ear disease does not respond to the usual treatment. The signs and symptoms are non-specific. Altering features include racial predisposition, contact or personal history of past or present tuberculosis, chronicity, development of a facial palsy and the pale granulation tissue found at the operation.
The American Journal of Human Genetics, 2001
Acta Oto-Laryngologica, 1996
The literature on neonatal hearing screening by means of oto-acoustic emissions (OAE's) p... more The literature on neonatal hearing screening by means of oto-acoustic emissions (OAE's) presents various prevalence figures, and gives little quantitative information on the procedure used to score the recordings. If the OAE test is to be interpreted by users who do not have the opportunity to develop intuitive interpretation skills through extensive training, a clear numerical decision criterion is needed. The present paper discusses the scoring procedure used by 25 teams, which together screen 22,356 neonates annually. More than 60% of the groups involved in this study use visual interpretation of the recorded OAE response, together with numerical criteria. Amongst the teams, 21 different ways of numerical scoring are used. It is shown that for a given set of OAE recordings, prevalence varies from 61% to 90%, depending on the numerical decision criterion being applied. We conclude that at this moment no consensus exists regarding the numerical criterion to be used when assessing OAE screening results. In view of the strong effect of criteria on the outcome of OAE screening, such consensus is urgently needed, but should be based on sensitivity and specificity figures for each scoring technique.
BACKGROUND AND PURPOSE: Only a few case reports and small series of intralabyrinthine schwan-noma... more BACKGROUND AND PURPOSE: Only a few case reports and small series of intralabyrinthine schwan-nomas (ILSs) have been reported. The purpose of this study was to assess prevalence, MR charac-teristics, location, clinical management, and growth potential/patterns of ILSs in the largest series reported. MATERIALS AND METHODS: Lesion localization, MR characteristics, lesion growth, and clinical man-agement were reviewed in 52 patients diagnosed with an ILS between February 1991 and August 2007 in 2 referral centers. The number of ILSs and vestibulocochlear schwannomas in the cerebel-lopontine angle/internal auditory canal was compared to assess the prevalence. RESULTS: ILSs most frequently originate intracochlearly, are hyperintense on unenhanced T1-weighted images, enhance strongly after gadolinium administration, and are sharply circumscribed and hypointense on thin heavily T2-weighted 3D images. The scala tympani is more frequently or more extensively involved than the scala vestibuli....
Acta oto-rhino-laryngologica Belgica, 2002
The present paper reports on the results of a retrospective study using 678 Hz susceptance-conduc... more The present paper reports on the results of a retrospective study using 678 Hz susceptance-conductance tympanometry performed on abnormally high admittant middle ears. High admittance was proven to be caused by (partial) disruption or lysis of the ossicular chain. Retrospective analysis shows that 678 Hz tympanometry seems to be more accurate in the differential diagnosis of ossicular chain disruptions compared to CT-imaging of the ossicular chain (88% versus 81% correct identification respectively). Classic tympanometry using a probe frequency of 226 Hz was abnormal in only 43% of the cases.
Acta oto-rhino-laryngologica Belgica, 1986
Nature genetics, 1998
The tectorial membrane is an extracellular matrix of the inner ear that contacts the stereocilia ... more The tectorial membrane is an extracellular matrix of the inner ear that contacts the stereocilia bundles of specialized sensory hair cells. Sound induces movement of these hair cells relative to the tectorial membrane, deflects the stereocilia, and leads to fluctuations in hair-cell membrane potential, transducing sound into electrical signals. Alpha-tectorin is one of the major non-collagenous components of the tectorial membrane. Recently, the gene encoding mouse alpha-tectorin (Tecta) was mapped to a region of mouse chromosome 9, which shows evolutionary conservation with human chromosome 11q (ref. 3), where linkage was found in two families, one Belgian (DFNA12; ref. 4) and the other, Austrian (DFNA8; unpublished data), with autosomal dominant non-syndromic hearing impairment. We determined the complete sequence and the intron-exon structure of the human TECTA gene. In both families, mutation analysis revealed missense mutations which replace conserved amino-acid residues within...