Poznan's program of cochlear and brainstem implantation: a general review.

The cochlear implantation program in Poznan started in January 1994. Within 8 years, 151 patients were implanted (149 cochlear and 2 auditory brain-stem implants). The implanted group comprised 111 children and 40 adults. We have extended the lower age limit for cochlear implant candidates, and the youngest implanted patient was 18-months-old at the time of surgery. We have also implanted six multi-handicapped subjects. All patients were implanted with different nucleus devices (22, 24 M, 24 K, 24 Contour, 24 Double Array and 24 ABI). Insertion of the Nucleus 24 Contour electrode carrier requires a little larger cochleostomy in comparison with conventional straight array. After insertion, the intraoperative measurements are taken (impedance telemetry, electrically evoked stapedius reflex and NRT). The day after surgery, each patient undergoes an X-ray examination (the cochleogram or cochlear view). The calculated length of the electrode array insertion was 12.75-24.0 mm (mean: 22.05 mm) and the degree of electrode rotation was 180-540 degrees (mean: 292.82 degrees). After speech processor switch-on, we performed NRT measurements. Our results indicated that the NRT threshold was in 51.4% of the dynamic range within the group of examined patients. The adults' progress of rehabilitation was checked during individual sessions. The rehabilitation of children included two rehabilitation schedules: continuous ones and weekly rehabilitation camps. The progress of the recovery process of implanted children enabled them to change their school profile from hearing impaired to mainstream. Voice rehabilitation is often monitored by acoustic analysis using the Multi Dimensional Voice Program (MDVP).

Audiological assessment of unilateral deafness.

Unilateral deafness constitute medical (aetiological diagnosis, treatment, hearing aid fitting) and social problems (no certification of disability). Following audiological examinations were performed in the study: pure tone audiometry (PTA), impedance audiometry, auditory brainstem responses (ABR), otoacoustic emissions (OAE), as well as balance, taste, examinations and electric sensitivity of the acoustic nerve. In cases of tinnitus the parameters of its character were done. All of our patients underwent X-ray investigations, i.e. ear X-ray by Schüller and Stenvers methods, computerized tomography or magnetic resonance imaging. In some cases phoniatric and logopaedic examinations were performed. For aetiological diagnosis electrophoresis and immunological test (IgG and IgM against mumps) were carried out. The results were presented in two groups of patients with sudden and those of long lasting progressive unilateral deafness. Some of the patients were pharmacologically treated before the evaluation. It is concluded that the statistic analysis could be a basis for the management and prognosis of the unilateral deafness.

[Otoacoustic emission evaluation in patients with tinnitus]. / Badanie otoemisji akustycznych u chorych z szumami usznymi.

Analysis of otoacoustic emission is highly objective, noninvasive and sensitive method representing cochlear function. In The Centre of ENT Rehabilitation in Poznan more than 900 patients were evaluated because of tinnitus. Standard tests were broaden by otoacoustic emission (SOAE, TEOAE, DPOAE) and results are discussed. Our results suggest that otoacoustic emission is possible to record in normally or with moderate hearing loss patients. 18 patients had SOAE. Only 2 patients had the same frequency of SOAE and tinnitus.

[First experiences in Neural Response Telemetry in patients with Nucleus 24 cochlear implant system]. / Wstepne doswiadczenia w stosowaniu telemetrii odpowiedzi nerwowych u pacjentów z wszczepem slimakowym Nucleus 24.

Nucleus 24 Cochlear Implant System enables bidirectional communication with the implant-telemetry. Information about implant function can be obtained using telemetry. Neural Response Telemetry is a measurement of neural activity in the cochlea as a response to electrical stimulation. Principle of NRT recording, classification of responses and examples of responses obtained in patients implanted in Poznan are presented.

[Critical evaluation of the audiological test results in children]. / Krytyczna ocena wyników badan audiologicznych u dzieci.

Factors influencing results of objective hearing examination in children, i.e. auditory evoked potentials, based on own experiences are presented. "Cross-check" principle as well as observation of dynamic changes concerning development of communicative process should be taken into the consideration.

[The electrophysiological examination of hearing with some metabolic disorders in children]. / Badania elektrofizjologiczne sluchu u dzieci w niektórych schorzeniach metabolicznych.

Electrophysiological examinations of hearing (ABR, SP) in 60 children with insulin-dependent diabetes mellitus and 39 children with obesitas simplex were done. In both groups with normal hearing threshold in pure tone audiometry disturbances in intrastem conduction were noticed.

[Electrophysiological hearing examination in children and teenagers with insulin-dependent diabetes mellitus]. / Badania elektrofizjologiczne narzadu sluchu u dzieci i mlodziezy z cukrzyca i mlodziezy z cukrzyca insulinozalezna.

In 60 children and youngsters aged 14-19 (average 16.5) with insulin dependent diabetes (lasting on average 5.5 years) and normal hearing in pure tone audiometry electrophysiological examinations (ABR, SP) were performed; 48% of the cases revealed changes in latencies of I, III, V waves, especially as an elongation of I and V waves. In the peripheral interlatencie (III-I; V-I) shortening and in V-III elongation were observed. In SP examination most often shortening of N1 (67%) and P2 (87%) were found. Statistically significant dependence of latency changes on the state of metabolic balance was stated. It was not found referring to the duration of diabetes, age and gender of the patients.

[Voice acoustic analysis in patients with a hearing aid or cochlear implant]. / Analiza akustyczna glosu u osób, u których zastosowano aparat sluchowy lub implant slimakowy.

The subject of our study was two groups of patients with hearing disorders: 23 cases implanted with multi-channel cochlear device (Nucleus Mini System 22) and 10 patients with perceptive hypoacusis who used hearing aids. The voice acoustic analysis was performed before cochlear implantation or application of a hearing aid and after a 6-month rehabilitation period. The acoustic analysis was carried out by means of a laryngophone connected to KAY 4300 instrument. The estimation of acoustic parameters of a laryngeal tone during rehabilitation process as well as parameters of spectrographic analysis was presented with the use of MDVP and CSL. Voice acoustic analysis can be an objective evaluation of progress in voice and speech rehabilitation process of patients with hearing disorders, particularly small children.

[Psychophysical and objective investigation of hearing in presbyacusis]. / Badanie psychofizyczne i obiektywne sluchu w presbyacusis.

In 30 individuals aged 50 to 82 the following audiologic examinations were performed: tonal audiometry (air/bone conduction), impedance audiometry (tympanometry and registration of stapedius reflex to pure tone of 0.5-4 kHz and noises) and ERA tests after acoustic stimulation from different levels of the hearing pathway (BERA, MLR and SP). The assessment of the results showed:--1. the threshold values in the objective methods are proportional to those obtained in tonal audiometry;--2. in ERA an interpersonal lability of latencies at different levels of the hearing pathway was observed including shortening, elongation and normal values;--3. in 70% of the examined aged 50-82 SRT were below 70 dB SL and loudness sumation below 25 dB;--4. shortening of the SP latencies was in 100% correlated to the low values of the loudness summation and recruitment found in psychophysical examinations.

[Functional voice evaluation after Reinke's edema treated with CO2 laser and Kleinsasser's microsurgery]. / Ocena czynnosciowa glosu po leczeniu obrzeków reinkego w mikrochirurgii laserowej CO2 oraz w mikrolaryngoskopii metoda wg Kleinsassera.

The authors performed functional evaluation of voice in 124 patients treated with microsurgery due to oedema Reincke in the years 1991-1994. In 90 patients surgery was performed with CO2 laser microsurgery and in 34 patients with microlaryngoscopy according to Kleinsasser. The picture of larynx was registered and evaluated with help of laryngovideostroboscopy. The voice status was evaluated in phoniatric examination, registered on tape and submitted to acoustic analysis. No correlation between method of surgical treatment and quality of voice was observed. However, significantly worse quality of voice was noted in those smoking after surgery.

The acoustic analysis of voice in patients with multi-channel cochlear implant.

The acoustic analysis of the voice was performed in 5 implanted patients (2 children and 3 adults). This analysis was made twice in each patient one week before the implantation and the second time at least three months later. The examination was carried out using the KAY Electronics 4300 instruments and the MDVP program. The comparison of the results showed: decreased F0 value of phonation tone after the surgery in all patients; mean values of jitter and shimmer were increased in relation to norm before and after the surgery in adults and children; the gap between harmonic signal and noise (NHR) was within norm in 2 adults, and in 1 child with prelingual deafness significantly decreased after the surgery. The acoustic analysis of voice of cochlear implant patients, especially children, may be the objective evaluation of progress in speech and hearing rehabilitation. In the process of rehabilitation tendencies pointing out to the normalization of voice especially in patients with prelingual deafness was observed.

[Pharmacological possibilities in treatment hypoacusis in children]. / Mozliwosci farmakologiczne leczenia niedosuchów odbiorczych u dzieci.

The purpose of this work was to present the dynamics of hearing thresholds and the progress in rehabilitation of hearing and speech according to the treatment applied and probable etiological factor of hypoacusis. Two groups of children were examined. The first group consisted of children with deep sensorineural hypoacusis together with central component of hypoacusis, whereas the second group included children with sudden occurrence of hypoacusis or detorioration of diminished hearing ability. The first group received a treatment with a drug stimulating the function of central nervous system, Cerebrolysin (Minden, D), whereas the other one underwent typical therapy applied in case of sudden deafness (mannitol, hydrocortison, vitamins, enzymes). Both the groups were subjected to objective examination of hearing before and after the treatment. The improvement in examination results in the first group was observed in 36%. In patients suffering from sudden deafness the improvement in hearing after treatment was found respectively in 30%.

[The Poznan program of the treatment of deafness by multichannel cochlear implants]. / Poznanski program leczenia gluchoty przy uzyciu wielokanalowego wszczepu slimakowego.

The authors presented 5 deaf patients with postlingual deafness and application of cochlear implant "Nucleus Mini System 22". In details operative technics and postoperative proceeding were described as well as rehabilitation results in 3-6 months after operation. The authors consider, that in adults with postlingual deafness, application of cochlear implants were giving very good effects.

Acoustic evaluation of voice in individuals with alcohol addiction.

The object of the study was the acoustic analysis of voice in individuals with alcohol addictions. The analysis showed an increase in medium and maximum jitter values, weakening of signal harmonic structure and an increase in periodical course occurrence with noise. All parameters of voice analysis in patients with alcohol addiction were compared with those of the control group.

[The first experience in diagnosis and rehabiliation in patients with cochlear implant "Nuclear Mini System 22"]. / Pierwsze doswiadczenia diagnostyczne i rehabilitacyjne u chorych przed i po zalozeniu wszczepu slimakowego "nucleus mini system 22".

The first qualification for cochlear implant "Nucleus" was performed on the basis of audiological tests. Next stage was conversation with a patient and his family about motivation of longterm rehabilitation. Then the two very important investigations were carried out--the computer tomography which showed inner ear structure, and electric promotory test. In rehabilitation process original "Nucleus" partially modified and Polish linguistic articulation lists were used.

[The influence of hearing aids on the ability of directional hearing in a free auditory field]. / Wplyw protez sluchowych na zdolnosc slyszenia kierunkowego w wolnym polu sluchowym.

The study was on subject of preservation of directional hearing in free auditory field, in horizontal plane in different stages of pathological lesions of the bearing organ with properly fits hearing aid from Viennatone as the behind-the-ear hearing aid (model 116 PAD) and the hearing spectacles (model 90 AN). There were noticed in 50 percentage of subjects improvement in the directional hearing. The best results was obtained in unilateral deafness. The evidently amelioration was observed in front azimuths. The obtained improvement directional hearing was not proportional to the stage of hearing improvement.

Usefulness of acoustic studies on the differential diagnostics of organic and functional dysphonia.

Phoniatric and acoustic examinations were carried out in a group of 30 patients with dysphonia, including 15 with organic type and 15 with functional type. A complex phoniatric assessment offered the possibility to differentiate between these two groups of pathological voices. This was achieved also on the basis of acoustic analysis of the voice by extracting characteristics such as: formant frequency, Fo and its range, percentage of noise in the analysed verbal text, mean and maximum values of jitter. The possibility of differential diagnosis of these two different types of dysphonia in acoustic studies was confirmed by clinical examinations. The acoustic studies presented can be regarded as a new approach to a fast and sufficiently precise method in the screening diagnostics of dysphonia conditioned by growth of the vocal fold mass.

VEP latency and some properties of simple motor reaction-time distribution.

The median of simple motor reaction (RT) to a flash parallels the latencies of visually evoked potential (VEP) deflections if flash intensity is varied. However, mean and median reaction times are not equal because of the skewness of RT distribution. It therefore seemed plausible that the mean reaction time--intensity relationship would be steeper than that for VEP latency. Such divergence would account for the intensity-dependent motor component of RT revealed by other psychophysical studies. The latencies of VEP deflections were measured as a function of intensity and the results were compared with mean and median RTs. The difference between mean and median RT is constant and independent of flash intensity. Moreover, both values are parallel to VEP latency. The general pattern of results remains the same after a change in the distribution from which the foreperiod is sampled.

[Objective topographic diagnosis of damage of the organ of hearing]. / Obiektywna topodiagnostyka uszkodzenia narzadu sluchu.

An analysis of the results of electrophysiologic examinations of hearing (impedance audiometry, BSER, MLR, SP) in 50 patients aged between 1 and 9 years perceptive bilateral hypoacusis reveals that the system of objective methods makes it possible not only the differentiation of cochlear and retrocochlear lesions, but also to demonstrate changes in upper part of the hearing tract. Electrophysiologic examinations of hearing help us to reveal the causes of failure in rehabilitation of speech and hearing and make possible to objectively study the conditions of hearing. In can be assumed that in the future combination of electrophysiologic methods with modern ways of imaging, changes in the nervous system will allow us to interpret by topographic diagnosis the results of EA examinations more deeply.