Safety has become an important issue, with the need to minimize the risk of transmitting infectio... more Safety has become an important issue, with the need to minimize the risk of transmitting infection to the cerebrospinal fluid. Hand-made electrode arrays are expensive and slow to make. Machine-made arrays have already been developed in Canada, and comparable techniques will, no doubt, arrive. If sufficient current can be transferred, using a centripetal design, smaller-diameter electrodes, less stiff than the present ones, will be less traumatic. Small diameter will probably mean special insertion tools to prevent buckling and over-riding of the tip. Future electrode arrays will probably include the option of cell growth-promoting drugs, for hair cells or to promote outward electrotrophic growth of dendrites towards the terminals.
The benefits of bilateral cochlear implantation in congenitally deaf children are well establishe... more The benefits of bilateral cochlear implantation in congenitally deaf children are well established. These mainly consist of better speech perception in the presence of background noise and the avai...
International journal of pediatric otorhinolaryngology, 1988
Cochlear implants now play a standard role in the management of adults with acquired profound sen... more Cochlear implants now play a standard role in the management of adults with acquired profound sensorineural deafness. Their role in children is more controversial. However, as demonstrated by a 1979 report on childhood deafness in the European Communities, there is no reason for complacency in the present management of profoundly deaf children. Transtympanic electrocochleography has been used as a method of estimating neural survival in deafened adults being assessed for the U.C.H./R.N.I.D. single channel extracochlear implant and also in a parallel group of profoundly deaf children referred by a paediatric hearing assessment clinic. In adults the effectiveness of electrocochleography in judging neural survival was monitored by electrical stimulation of the cochlea and found to be significantly effective. This result was extrapolated to the paediatric group to estimate the proportion of congenitally deaf children who might benefit from a cochlear implant. It is suggested that in a p...
... Res. 57 (1991), pp. 2330. Abstract | PDF (1006 K) | View Record in Scopus | Cited By in Scop... more ... Res. 57 (1991), pp. 2330. Abstract | PDF (1006 K) | View Record in Scopus | Cited By in Scopus (17). 4. LS De-Vries, S. Larry, AG Whitelaw and LM Dubowitz, Relationship of serum bilirubin levels and hearing impairment in newborn infants. Early Hum. Dev. 15 (1987), pp. ...
Postlingually deaf subjects learn the meaning of sounds after cochlear implantation by forming ne... more 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.
To evaluate the speech perception benefits of bilateral implantation for subjects who already hav... more To evaluate the speech perception benefits of bilateral implantation for subjects who already have one implant. Repeated measures. Thirty adult cochlear implant users who received their second implant from 1 to 7 years with a mean of 3 years after their first device. Ages ranged from 29 to 82 years with a mean of 57 years. Tertiary referral centers across the United Kingdom. Monosyllabic consonant-nucleus-consonant words and City University of New York sentences in quiet with coincident speech and noise and with the noise spatially separated from the speech by +/-90 degrees . At 9 months, results showed the second ear in noise was 13.9 +/- 5.9% worse than the first ear (p < 0.001); a significant binaural advantage of 12.6 +/- 5.4% (p < 0.001) over the first ear alone for speech and noise from the front; a 21 +/- 6% (p < 0.001) binaural advantage over the first ear alone when noise was ipsilateral to the first ear; no binaural advantage when noise was contralateral to the first ear. There is a significant bilateral advantage of adding a second ear for this group. We were unable to predict when the second ear would be the better performing ear, and by implanting both ears, we guarantee implanting the better ear. Sequential implantation with long delays between ears has resulted in poor second ear performance for some subjects and has limited the degree of bilateral benefit that can be obtained by these users. The dual microphone does not provide equivalent benefit to bilateral implants.
To investigate changes in cochlear orientation with age and discuss the implications of any chang... more To investigate changes in cochlear orientation with age and discuss the implications of any change with respect to cochlear implantation. Cross-sectional study of computed tomographic scans of the temporal bones in patients with no congenital abnormalities. One hundred fifty-nine patients were included in the study, making a total of 318 ears. The age range was 9 months to 85 years. Axial computed tomographic scans showing the basal turn of the cochlea were identified. The angle of the basal turn of the cochlea was measured by drawing a line through the long axis of the basal turn and measuring its angle with a line drawn through the midsagittal plane. The patients were grouped according to age, and a 1-way analysis of variance was used to identify any statistically significant change in basal turn angulation. Interobserver and intraobserver errors were calculated and presented as repeatability coefficients. The basal turn angles of 3 difficult cases of cochlear implantation were related to the findings. The mean basal turn angle was 54.6 degrees (range, 46.8-63.8 degrees; standard deviation, 3.5). There was a statistically significant reduction in the angulation of the basal turn with increasing age (F = 10.1; p = 0.002). The majority of the change occurs between the ages of 11 and 15 years. The interobserver reliability coefficient was 4.8. The intraobserver reliability coefficient was 2.0. The 3 difficult cases had basal turn angles that were at the upper limit of the reference range. There is a statistically significant reduction in basal turn angulation relative to the midsagittal plane with increasing age. However, care should be taken in interpreting these results in light of the inherent error in the measuring technique, although the intraobserver repeatability coefficient was only 2.0. The more obtuse angulation of the basal turn in children may have implications for cochlear implantation.
... Mr Graham's present address is: University College Hospital, Gower Srreet, London WCI . ... more ... Mr Graham's present address is: University College Hospital, Gower Srreet, London WCI . ... References References should be indicated in the text by numbers following the author's name, ie Skeggs [6]. In the reference section they should be arranged as follows: to a journal: ...
The objective of this review is to analyze aspects of congenital malformation of the ear in relat... more The objective of this review is to analyze aspects of congenital malformation of the ear in relation to cochlear implantation in children. Having briefly described the in utero development of the ear and the classification of types of external, middle and inner ear malformation, five practical aspects of these malformations are discussed. It seems likely that the combination of bilateral profound sensorineural deafness with bilateral microtia severe enough to make a surgical approach to the cochlea difficult will be extremely uncommon. No such cases have been reported, although Klippel-Feil deformity seems the syndrome most likely to produce this set of circumstances.Abnormalities in the intratympanic course of the facial nerve have been associated with cochlear malformation, emphasizing the benefit of intra-operative facial nerve monitoring, and a technique suggested for safely avoiding an abnormally placed nerve. Fistulae of cerebrospinal fluid (CSF) and perilymph can complicate s...
TJ BALKANY, AV HODGES, CA BUCHMAN, WM LUXFORD, CH PILLSBURY, PS ROLAND, JK SHALLOP, DD BACKOUS, D... more TJ BALKANY, AV HODGES, CA BUCHMAN, WM LUXFORD, CH PILLSBURY, PS ROLAND, JK SHALLOP, DD BACKOUS, D FRANZ, JM GRAHAM, B HIRSCH, M LUNTZ, JK NIPARKO, J PATRICK, SL PAYNE, S STALLER, FF TELISCHI, EA TOBEY, E TRUY, University of ...
This paper describes the relationship between the scores obtained in the Bamford, Kowal and Bench... more This paper describes the relationship between the scores obtained in the Bamford, Kowal and Bench (BKB) sentence test and the Arthur Boothroyd (AB) word test in quiet for a group of 71 cochlear implant users. Each subject was tested at the same appointment and in the same environment during routine clinical appointments at the South of England Cochlear Implant Centre.Using rationalised arcsine transformation and a linear regression calculation, conversion tables were produced from BKB to AB and from AB to BKB scores. The relationship between scores obtained from the two tests was highly significant.These conversion tables may be of use in cochlear implant centres and by audiology clinics.
This study attempts to answer the question of whether there is a &amp... more This study attempts to answer the question of whether there is a 'critical age' after which a second contralateral cochlear implant is less likely to provide enough speech perception to be of practical use. The study was not designed to predict factors that determine successful binaural implant use, but to see if there was evidence to help determine the latest age at which the second ear can usefully be implanted, should the first side fail and become unusable.Outcome data, in the form of speech perception test results, were collected from 11 cochlear implant programmes in the UK and one centre in Australia. Forty-seven congenitally bilaterally deaf subjects who received bilateral sequential implants were recruited to the study. The study also included four subjects with congenital unilateral profound deafness who had lost all hearing in their only hearing ear and received a cochlear implant in their unilaterally congenitally deaf ear. Of those 34 subjects for whom complete sets of data were available, the majority (72%) of those receiving their second (or unilateral) implant up to the age of 13 years scored 60 per cent or above in the Bamford Kowal Bench (BKB) sentence test, or equivalent. In contrast, of those nine receiving their second or unilateral implant at the age of 15 or above, none achieved adequate levels of speech perception on formal testing: two scored 29 per cent and 30 per cent, respectively, and the rest seven per cent or less.A discriminant function analysis performed on the data suggests that it is unlikely that a second contralateral implant received after the age of 16 to 18 years will, on its own, provide adequate levels of…
This study describes open-set speech recognition in cochlear implant subjects with ossified cochl... more This study describes open-set speech recognition in cochlear implant subjects with ossified cochleae and compares it to a control group with open cochleae. Twenty-one postlingually deafened adults with a Med-El Combi 40/40+GB split- electrode implant were matched to patients using a Med-El cochlear implant with a standard electrode. Speech recognition was assessed over an 18-month period. Split- electrode patients improved significantly over time, but their scores were significantly lower and increased significantly slower than those of controls. Of 14 patients with a duration of deafness less than 20 years, average sentence test scores were 50%, and average monosyllabic word test scores were 31%. This study provides evidence that cochlear implantation is beneficial to patients with ossified cochleae, but early implantation is advisable.
Safety has become an important issue, with the need to minimize the risk of transmitting infectio... more Safety has become an important issue, with the need to minimize the risk of transmitting infection to the cerebrospinal fluid. Hand-made electrode arrays are expensive and slow to make. Machine-made arrays have already been developed in Canada, and comparable techniques will, no doubt, arrive. If sufficient current can be transferred, using a centripetal design, smaller-diameter electrodes, less stiff than the present ones, will be less traumatic. Small diameter will probably mean special insertion tools to prevent buckling and over-riding of the tip. Future electrode arrays will probably include the option of cell growth-promoting drugs, for hair cells or to promote outward electrotrophic growth of dendrites towards the terminals.
The benefits of bilateral cochlear implantation in congenitally deaf children are well establishe... more The benefits of bilateral cochlear implantation in congenitally deaf children are well established. These mainly consist of better speech perception in the presence of background noise and the avai...
International journal of pediatric otorhinolaryngology, 1988
Cochlear implants now play a standard role in the management of adults with acquired profound sen... more Cochlear implants now play a standard role in the management of adults with acquired profound sensorineural deafness. Their role in children is more controversial. However, as demonstrated by a 1979 report on childhood deafness in the European Communities, there is no reason for complacency in the present management of profoundly deaf children. Transtympanic electrocochleography has been used as a method of estimating neural survival in deafened adults being assessed for the U.C.H./R.N.I.D. single channel extracochlear implant and also in a parallel group of profoundly deaf children referred by a paediatric hearing assessment clinic. In adults the effectiveness of electrocochleography in judging neural survival was monitored by electrical stimulation of the cochlea and found to be significantly effective. This result was extrapolated to the paediatric group to estimate the proportion of congenitally deaf children who might benefit from a cochlear implant. It is suggested that in a p...
... Res. 57 (1991), pp. 2330. Abstract | PDF (1006 K) | View Record in Scopus | Cited By in Scop... more ... Res. 57 (1991), pp. 2330. Abstract | PDF (1006 K) | View Record in Scopus | Cited By in Scopus (17). 4. LS De-Vries, S. Larry, AG Whitelaw and LM Dubowitz, Relationship of serum bilirubin levels and hearing impairment in newborn infants. Early Hum. Dev. 15 (1987), pp. ...
Postlingually deaf subjects learn the meaning of sounds after cochlear implantation by forming ne... more 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.
To evaluate the speech perception benefits of bilateral implantation for subjects who already hav... more To evaluate the speech perception benefits of bilateral implantation for subjects who already have one implant. Repeated measures. Thirty adult cochlear implant users who received their second implant from 1 to 7 years with a mean of 3 years after their first device. Ages ranged from 29 to 82 years with a mean of 57 years. Tertiary referral centers across the United Kingdom. Monosyllabic consonant-nucleus-consonant words and City University of New York sentences in quiet with coincident speech and noise and with the noise spatially separated from the speech by +/-90 degrees . At 9 months, results showed the second ear in noise was 13.9 +/- 5.9% worse than the first ear (p < 0.001); a significant binaural advantage of 12.6 +/- 5.4% (p < 0.001) over the first ear alone for speech and noise from the front; a 21 +/- 6% (p < 0.001) binaural advantage over the first ear alone when noise was ipsilateral to the first ear; no binaural advantage when noise was contralateral to the first ear. There is a significant bilateral advantage of adding a second ear for this group. We were unable to predict when the second ear would be the better performing ear, and by implanting both ears, we guarantee implanting the better ear. Sequential implantation with long delays between ears has resulted in poor second ear performance for some subjects and has limited the degree of bilateral benefit that can be obtained by these users. The dual microphone does not provide equivalent benefit to bilateral implants.
To investigate changes in cochlear orientation with age and discuss the implications of any chang... more To investigate changes in cochlear orientation with age and discuss the implications of any change with respect to cochlear implantation. Cross-sectional study of computed tomographic scans of the temporal bones in patients with no congenital abnormalities. One hundred fifty-nine patients were included in the study, making a total of 318 ears. The age range was 9 months to 85 years. Axial computed tomographic scans showing the basal turn of the cochlea were identified. The angle of the basal turn of the cochlea was measured by drawing a line through the long axis of the basal turn and measuring its angle with a line drawn through the midsagittal plane. The patients were grouped according to age, and a 1-way analysis of variance was used to identify any statistically significant change in basal turn angulation. Interobserver and intraobserver errors were calculated and presented as repeatability coefficients. The basal turn angles of 3 difficult cases of cochlear implantation were related to the findings. The mean basal turn angle was 54.6 degrees (range, 46.8-63.8 degrees; standard deviation, 3.5). There was a statistically significant reduction in the angulation of the basal turn with increasing age (F = 10.1; p = 0.002). The majority of the change occurs between the ages of 11 and 15 years. The interobserver reliability coefficient was 4.8. The intraobserver reliability coefficient was 2.0. The 3 difficult cases had basal turn angles that were at the upper limit of the reference range. There is a statistically significant reduction in basal turn angulation relative to the midsagittal plane with increasing age. However, care should be taken in interpreting these results in light of the inherent error in the measuring technique, although the intraobserver repeatability coefficient was only 2.0. The more obtuse angulation of the basal turn in children may have implications for cochlear implantation.
... Mr Graham's present address is: University College Hospital, Gower Srreet, London WCI . ... more ... Mr Graham's present address is: University College Hospital, Gower Srreet, London WCI . ... References References should be indicated in the text by numbers following the author's name, ie Skeggs [6]. In the reference section they should be arranged as follows: to a journal: ...
The objective of this review is to analyze aspects of congenital malformation of the ear in relat... more The objective of this review is to analyze aspects of congenital malformation of the ear in relation to cochlear implantation in children. Having briefly described the in utero development of the ear and the classification of types of external, middle and inner ear malformation, five practical aspects of these malformations are discussed. It seems likely that the combination of bilateral profound sensorineural deafness with bilateral microtia severe enough to make a surgical approach to the cochlea difficult will be extremely uncommon. No such cases have been reported, although Klippel-Feil deformity seems the syndrome most likely to produce this set of circumstances.Abnormalities in the intratympanic course of the facial nerve have been associated with cochlear malformation, emphasizing the benefit of intra-operative facial nerve monitoring, and a technique suggested for safely avoiding an abnormally placed nerve. Fistulae of cerebrospinal fluid (CSF) and perilymph can complicate s...
TJ BALKANY, AV HODGES, CA BUCHMAN, WM LUXFORD, CH PILLSBURY, PS ROLAND, JK SHALLOP, DD BACKOUS, D... more TJ BALKANY, AV HODGES, CA BUCHMAN, WM LUXFORD, CH PILLSBURY, PS ROLAND, JK SHALLOP, DD BACKOUS, D FRANZ, JM GRAHAM, B HIRSCH, M LUNTZ, JK NIPARKO, J PATRICK, SL PAYNE, S STALLER, FF TELISCHI, EA TOBEY, E TRUY, University of ...
This paper describes the relationship between the scores obtained in the Bamford, Kowal and Bench... more This paper describes the relationship between the scores obtained in the Bamford, Kowal and Bench (BKB) sentence test and the Arthur Boothroyd (AB) word test in quiet for a group of 71 cochlear implant users. Each subject was tested at the same appointment and in the same environment during routine clinical appointments at the South of England Cochlear Implant Centre.Using rationalised arcsine transformation and a linear regression calculation, conversion tables were produced from BKB to AB and from AB to BKB scores. The relationship between scores obtained from the two tests was highly significant.These conversion tables may be of use in cochlear implant centres and by audiology clinics.
This study attempts to answer the question of whether there is a &amp... more This study attempts to answer the question of whether there is a 'critical age' after which a second contralateral cochlear implant is less likely to provide enough speech perception to be of practical use. The study was not designed to predict factors that determine successful binaural implant use, but to see if there was evidence to help determine the latest age at which the second ear can usefully be implanted, should the first side fail and become unusable.Outcome data, in the form of speech perception test results, were collected from 11 cochlear implant programmes in the UK and one centre in Australia. Forty-seven congenitally bilaterally deaf subjects who received bilateral sequential implants were recruited to the study. The study also included four subjects with congenital unilateral profound deafness who had lost all hearing in their only hearing ear and received a cochlear implant in their unilaterally congenitally deaf ear. Of those 34 subjects for whom complete sets of data were available, the majority (72%) of those receiving their second (or unilateral) implant up to the age of 13 years scored 60 per cent or above in the Bamford Kowal Bench (BKB) sentence test, or equivalent. In contrast, of those nine receiving their second or unilateral implant at the age of 15 or above, none achieved adequate levels of speech perception on formal testing: two scored 29 per cent and 30 per cent, respectively, and the rest seven per cent or less.A discriminant function analysis performed on the data suggests that it is unlikely that a second contralateral implant received after the age of 16 to 18 years will, on its own, provide adequate levels of…
This study describes open-set speech recognition in cochlear implant subjects with ossified cochl... more This study describes open-set speech recognition in cochlear implant subjects with ossified cochleae and compares it to a control group with open cochleae. Twenty-one postlingually deafened adults with a Med-El Combi 40/40+GB split- electrode implant were matched to patients using a Med-El cochlear implant with a standard electrode. Speech recognition was assessed over an 18-month period. Split- electrode patients improved significantly over time, but their scores were significantly lower and increased significantly slower than those of controls. Of 14 patients with a duration of deafness less than 20 years, average sentence test scores were 50%, and average monosyllabic word test scores were 31%. This study provides evidence that cochlear implantation is beneficial to patients with ossified cochleae, but early implantation is advisable.
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