Paul van den Broek

The effect of cochlear implant use in postlingually deaf adults

OBJECTIVE To assess the effect of the use of cochlear implants (CI) on the health status of postlingually deaf adults. METHODS Participants comprised 45 postlingually deaf adult multichannel CI users and 46 deaf candidates on the waiting list for a CI. The latter group acted as control subjects to corroborate the validity of retrospective completion of the questionnaires by the CI recipients. Three HRQOL instruments were used: a) a specially developed CI questionnaire (NCIQ); b) a generic HRQOL questionnaire (SF-36); and c) a health-state classification system (HUI-2) suited to estimate single preference scores. RESULTS Retrospectively estimated pre-implant scores in the CI user group corresponded very well with the scores in the control group. Postimplant scores in the CI users were substantially higher in all six domains (p < .001) of the NCIQ than the scores in the control group. Effects due to a CI were also observed with the SF-36 in five of the seven domains (p < .01). Statistically significant differences between the two groups (p = .001) were observed in two of the six domains of the HUI-2. CONCLUSIONS All three questionnaires detected improvements in HRQOL due to CI use. To make a detailed assessment of the effect of a CI on functional outcomes and well-being, a special purpose HRQOL instrument is far more adequate than a general HRQOL instrument. This study also showed that a CI affects several other health domains besides auditory performance. The effect of CI use on general functioning and well-being proved to be considerable.

Age effects and normative data on a Dutch test battery for auditory processing disorders.

A test battery compiled to diagnose auditory processing disorders (APDs) in an adult population was used on a population of 9–16-year-old children. The battery consisted of eight tests (words-in noise, filtered speech, binaural fusion, dichotic digits, frequency and duration patterns, backward masking, categorical perception, digit span) and a questionnaire. Descriptive statistics were computed on data obtained from 75 children from primary school (age 9–12 years) and 30 adolescents from secondary school (age 14–16 years) with normal hearing and normal intelligence. Most test scores did not follow a normal distribution. Age effects were present in most tests, within the group as well as when children and adolescents were compared to adults. This suggests that maturation of auditory processing abilities takes place even during adolescence. Relative measures regarding ear differences and binaural versus monaural scores did not appear to be age-related. These measures might be useful in diagnosing APD, supplementary to the absolute measures. Factor analysis showed four components that address underlying processes. However, these results must be interpreted cautiously because the study did not include any subjects with APD. Sumario Una bateria de pruebas elaborada para diagnosticar problemas de procesamiento auditivo (APD) en adultos fue utilizada en una población de 9 a 16 años. Esta serie estaba constituida por ocho pruebas (palabras en ruido, lenguaje filtrado, fusión binaural, digitos dicótícos, patrones de frecuencia y duración, enmascaramienlo invertido. percepción de calegorías, memoria de dígitos a corto plazo) y un cuestionario. Se presenta una estadística descriptiva obtenida de 75 niños de escucla primaria (edad 9–12 años) y 30 adolescentes de secundaria (edad 14–16 años) con audición e inteligcncia normales. La mayor parte de los resultados de las pruebas no mostraron una distribución normal. En la mayor parte de ellas, la edad luvo un efecto dentro de cada grupo y también al comparar a los niños y adolescentes con los adultos. Esto sugiere que la maduración de las habilidades en el procesamiento auditivo ocurre incluso durante la adolescencia. Al parecer no hay una influencia de la edad sobre los resultados concernientes a latcralidad o binauralidad vs monoauralidad. Es posible que estas mediciones sean utiles en forma complementaria a las mediciones absolutas de los APD. El análisis factorial demuestra cuatro componentes que señalan procesos subyacentes. Sin embargo, estos resultados deben ser interpretados cautelosamente porque el estudio no incluyó a ningún sujeto con APD.

Does intracochlear implantation jeopardize vestibular function

We present the results of the vestibular function tests of 35 patients who were selected for cochlear implantation. Vestibular function was evaluated with a caloric test and a velocity step test. The preimplant data were compared to those in previously reported series. Intracochlear implantation was performed in 25 patients. The vestibular complications encountered in this group are presented and discussed. Six patients had normal or residual (but substantial) vestibular function in the ear eligible for implantation. Vestibular function was preserved in 3 patients and was lost in 3 patients, in 1 case through an iatrogenic cause. We estimate the risk of losing vestibular function as a result of intracochlear implantation as between 50% and 60% on the basis of the present and previously reported data.

Evaluation of cochlear implant benefit with auditory cortical evoked potentials.

Endogenous P300 and exogenous slow vertex potentials were obtained with tone and speech stimuli in a group of five children using a cochlear implant (CI) with poor speech recognition (group A) and compared with those from another group of five children using a CI with good speech recognition (group B). The responses were also compared to those of children with normal hearing (n = 14) and a group of adult CI users (n = 9). N1 and P2 latencies of CI group A and group B were prolonged compared to those of normally-hearing children. In group A, P300 was present when contrasts with tone stimuli were used. When speech stimuli were used, P300 potentials were absent or delayed. P300 potentials obtained in group B were no different from those obtained in normally-hearing children. It is suggested that the poor results evoked with speech stimuli in contrast to those evoked with pure-tone stimuli in group A are due to the immaturity of (sub) cortical generators associated with acoustical and phonetic processing. In contrast to the children in group B, all children in group A suffered from congenital deafness. Sumario Se compararon los potenciales endógenos P300 y los potenciales exógenos lentos del vértex con estímulos tonales y de lenguaje en dos grupos diferentes. El grupo A estaba conformado por cinco niños con implante coclear, con pobre discriminación del lenguaje. El grupo B igual-mente conformado por cinco niños, pero con buena discriminación del lenguaje. Las respuestas también fueron comparadas con las de niños con audición normal (n = 14) y con un grupo de adultos con implante coclear (n = 9). Las latencias de N1 y P2 estaban prolongadas en los grupos A y B en comparación con las de los niños normoyentes. En el grupo A, la P300 se presentó cuando se utilize contraste con el estimulo tonal. Cuando se utilizó estímulo lingüístico la P300 estuvo ausente o retrasada. Los potenciales obtenidos en el grupo B no mostraron diferencia con aquellos obtenidos en niños normoyentes. Se piensa que la inmadurez de los generadores (sub) corticales asociados con el procesamiento fonético y acústico, son la causa de los pobres resultados obtenidos con el estímulo lingüístico que con-trastan con los resultados obtenidos al estimular con tonos puros. A diferencia de los niños del grupo B, la sordera de los niños en el grupo A era congenita.

Auditory processing disorders in adults and children: evaluation of a test battery.

A Dutch test battery comprising six different tests for auditory processing disorders was evaluated in a group of 49 adults and children (age 8–57 years) with auditory complaints despite normal audiometric thresholds. Percentile scores were derived from normal control groups (n = 132) to determine whether a subject passed or failed a test. A composite score was computed to reflect a general score on all the auditory processing tests. In order to gain insight into underlying auditory processes, factor analysis was performed. Normal scores on all the tests were seen in five subjects. The remaining 44 subjects had at least one test score that was below the cut-off point (10th percentile). Factor analysis provided evidence for a model comprising four auditory components: auditory sequencing, word recognition in noise, auditory closure, and auditory patterning. This model could be useful in the interpretation of scoring patterns. Although there were some differences in scoring patterns between the children and adults, the test battery proved to be useful in both groups.

Results from Four Cochlear Implant Patients with Usher's Syndrome

Individual results are presented of 4 patients with Ushers syndrome type 1 who received a cochlear implant. Both single-channel and multichannel implants were used. Because of implant failure, one of the single-channel systems was replaced by a Nucleus multichannel system. Results are compared to the results of 5 other prelingually deaf cochlear implant users. The performance of the patients with Ushers syndrome on suprasegmental and segmental speech perception tests and on a connected discourse tracking task did not differ significantly from the performance of the other prelingually deaf patients. A significant improvement over time was found at the suprasegmental level for the combined group of Ushers and other patients. No obvious differences were found between the scores from the patients with a single-channel and the patients with a multichannel device. The rehabilitation of the Ushers patients required very little extra effort in comparison with that of the other prelingually deaf patients; all patients reported considerable advantages in hearing abilities and social life.

Assessment of auditory processing in 6-year-old language-impaired children

The performance of a group of twenty 6-year-old children with specific language impairment (SLI) on several behavioural auditory tests was compared to that of a group of twenty age-matched control children. The auditory test battery used in this study consisted of the following tests: a speech-in-noise test, a filtered speech test, a binaural fusion test, a frequency pattern test, a duration pattern test, a temporal integration test, an auditory word discrimination test, an auditory synthesis test, an auditory closure test and a number recall test. Our results show that the SLI children obtained scores on almost all tests that were significantly lower than those of the control group. Many of the basic auditory processing measures in our test battery correlated significantly with receptive and language scores, suggesting a (causal) relationship between auditory processing and language proficiency. Results from discriminant function analyses do not warrant deleting one or more tests from the test battery yet (with the exception of the auditory synthesis test and the temporal integration test, for which we did not find significant group effects). At present, we are conducting experiments with older (SLI and control) children and adults to find whether the significant performance deficits of the SLI children are also found in older SLI children, and to determine the influence of maturational effects on these auditory tests. Sumario Se comparó el rendimiento en varias pruebas conductuales auditivas de un grupo de veinte niños de 6 años de edad con deficiencies específicas del lenguaje (SLI), con el de un grupo control de veinte niños con edades similares. La batería de pruebas auditivas utilizada en este estudio consistió en: una prueba de lenguaje en ruido, una prueba de lenguaje filtrado, una prueba de fusión binaural, una prueba de patrones de frecuencia, una prueba de patroncs de duración, una prueba de integración temporal, una prueba de discriminatión auditiva del habla, una prueba de síntesis auditiva, una prueba de cierre auditivo y una prueba de memoria de números. Nuestros resultados muestran que los niños con SLI lograron, en casi todas las pruebas, puntuaciones significativamente más bajas que aquellas del grupo control. Muchas de las medidas básicas de procesamiento auditivo de nuestra batería de pruebas mostraron una correlación significaliva con las puntuaciones de recepción y del lenguaje, sugiriendo una relación causal entre el procesamiento auditivo y la competencia lingüística. Los resultados de los análisis de función discriminatoria no sugieren aún la eliminatión de una o más pruebas de la batería (con la excepción de la prueba de síntesis auditiva y la de integración temporal, para las cuáles no encontramos un cfecto significativo de grupo). Actualmente, estamos conduciendo experimentos con niños mayores (con SLI y en grupo control) y con adultos, para averiguar si las deficiencias significativas de rendimiento en los niños con SLI se encuentran también en niños mayores con SLI, y determinar así la influencia de un efecto de maduración en estas pruebas auditivas.

Planned preoperative radiation therapy vs. definitive radiotherapy for advanced laryngeal carcinoma

In the period 1970‐1980 inclusive, 191 patients with T3T4 laryngeal carcinoma (glottic.: 63 and supraglottic.: 128) received either definitive radiation therapy (RT) (60‐65 Gy in 6‐7 weeks) or planned preoperative radiation therapy (25 Gy in 5 equal daily fractions of 5 Gy) followed by laryngectomy with or without neck dissection (RT+S).

Planned preoperative radiation therapy for advanced laryngeal carcinoma

One hundred ten patients with predominantly advanced laryngeal carcinoma were treated in the period 1969-1978 with planned preoperative radiation therapy followed by surgery. Site distribution was: 63 supraglottic, 26 glottic, 15 transglottic and 6 subglottic. There were 4 Stage II patients, 66 Stage III and 40 Stage IV. Preoperative radiation therapy consisted of Telecobalt irradiation to a total dose of 25 Gy given to a target volume encompassing the larynx and regional neck nodes, given in 5 equal daily fractions of 5 Gy in 5 consecutive days. Surgery was performed 2 days later. Total laryngectomy was performed on 48 patients, total laryngectomy with neck dissection on 55 patients, supraglottic laryngectomy on 5 and supraglottic laryngectomy with neck dissection on 2 patients. Crude actuarial 5 and 10 year survival probability for the whole group is 71 and 61%, respectively. The corrected 5 and 10 year survival is 75%. For patients with T3-T4-N0 tumors 5 and 10 year survival probability is: crude 65 and 58%, and corrected 70% respectively. For T3-T4-N+ crude: 75 and 60% and corrected: 78%. Of 110 patients, one died postoperative, three died of intercurrent disease, five died as a result of second malignancy, and 23 died of their larynx carcinoma: 12/23 because of locoregional failure, and 11/23 because of distant metastasis. We concluded that short intensive preoperative radiation therapy and surgery offer a high cure rate in the treatment of advanced resectable laryngeal carcinoma. The merits of this technique are outlined in the text.

Electrical impedance of the cochlear implant lubricants hyaluronic acid, oxycellulose, and glycerin

Hyaluronic acid (Healon), oxycellulose (hydroxypropyl methylcellulose), and glycerin are lubricants used in cochlear implant surgery for atraumatic deep insertion of the electrode array into the scala tympani. The electrical impedances of these three lubricants were measured to assess possible effects on intraoperative evoked response measurements, such as the electrically evoked stapedius reflex and auditory brain stem response. The impedances of hyaluronic acid, oxycellulose, and saline were very similar and independent of frequency (20 Hz to 1 MHz). Glycerin had an excessively high impedance at low frequencies. A film of hyaluronic acid or oxycellulose around the electrode array immersed in saline did not have any measurable effect on the impedance; a film of glycerin resulted in a strongly reactive polarized layer. However, neither the far-field current spread nor the impedance between stimulated electrodes was affected by any of the lubricants applied as a thin film. This suggests that none of these lubricants affect intraoperative responses, when applied as a thin film.