Anke Lesinski-Schiedat

Hearing Conservation Surgery Using the Hybrid-L Electrode

Patients with high-frequency deafness and/or substantial residual hearing across frequencies might benefit from combined electro-acoustic stimulation. The Hybrid-L electrode was designed to address the issues of both hearing conservation and effective electrical stimulation in those recipients. The electrode with 22 contacts should be inserted through the round window membrane, and covers approximately 270° of the basal turn of the cochlear. This insertion length is equivalent to the one seen in many patients using the former Nucleus straight electrode. Twenty-four patients with low-frequency thresholds of 60 dB or better, up to 500 Hz, were implanted with a Hybrid-L device in a clinical trial at the Medical University of Hannover. Another group of 8 recipients with less residual hearing was included under extended inclusion criteria. Residual hearing was conserved in the majority of cases. One patient had a loss of more than 30 dB, but hearing partially recovered after 9 months. The median loss in all patients was 10 dB in both the Hybrid group and the extended group. Patients were able to use the residual hearing postoperatively to the same extent as preoperatively. In the Hybrid mode (cochlear implant + ipsilateral hearing aid), patients showed a significant improvement of 21% (p = 0.002) in speech understanding in quiet using the Freiburger Monosyllabic Word Test compared to the preoperative scores under aided conditions with their hearing aid. The Oldenburg Sentence Test in noise showed a remarkable average improvement of 10.2 dB (p < 0.001) compared to the preoperative hearing aid only mode. An additional improvement could be seen in the combined mode using an additional contralateral hearing aid. Recipients with a shorter duration of high-frequency hearing loss showed a larger benefit than those with a longer duration of hearing loss. Hearing conservation using the Hybrid-L electrode and a given surgical technique is possible with high probability in patients with high-frequency deafness or pantonal hearing loss. The use of the residual acoustic hearing offers specific advantages, especially for understanding speech in noise and for spatial hearing.

Audiological performance in cochlear implanted patients deafened by meningitis depending on duration of deafness

The objective of our study was to evaluate audiological outcome in cochlear implanted children deafened by meningitis and its correlation with duration of deafness from meningitis in a retrospective clinical study at an academic tertiary referral center. Sixty patients profoundly deafened by meningitis were evaluated. Two groups of children depending on duration of deafness—group 1 defined by duration of deafness less than 6xa0months and group 2 defined by duration of deafness over 6xa0months were evaluated. The control group A (duration of deafness <6xa0months) and group B (duration of deafness >6xa0months) with similar demographics data and a non-meningitis-related cause of deafness were evaluated. Patient history, cochlear implantation and audiological findings (MAIS, MUSS and open set tests questionnaire) were investigated. Standardized diagnostic and therapeutic procedure was performed in all patients. Our results showed better auditory performance and language control in children implanted within 6xa0months after meningitis. Over the period of 36xa0months group 2 was able to catch up with the group 1 in the MUSS and MAIS tests. However, the results of the common phrases test remain significantly better in group 1 over this time period (Pxa0=xa00.0188). In case of meningitis, audiological and radiological assessment should be performed within 4xa0weeks after the onset of disease. We see a clear indication for immediate implantation in patients with profound SNHL caused by meningitis. The aim should be bilateral implantation in this population to achieve the best possible performance by implantation before obliteration occurs. Premeningetic auditory experience is an important advantage which should be used. Frequent bilateral and sometimes late obliteration should be taken into consideration in the decision-making process as well.

Spontaneous increases in impedance following cochlear implantation: Suspected causes and management

Modern cochlear implant systems deliver impulse transmission rates up to 50 000 pps. It emerged that the fast stimulation rates led to enhanced speech comprehension. Impedance measurement is an important aspect in cochlear implant testing procedures. Impedance values are a measure of the electrical resistance between the individual implant electrodes. Increased impedances were attributed frequently to inflammatory/tissue-related processes. In recent years, however, we have repeatedly found cases of impedance increase for which the inflammatory model did not provide a satisfactory explanation. The aim of this study is to evaluate increases in impedance in our cochlear implant population, to attempt to find their cause, and to formulate therapeutic hypotheses. In our cochlear implant programme (> 3000 recipients) we screened our database for impedance increases over time during device fitting. We found 16 patients with 18 affected ears in whom impedance increases were clearly demonstrated. We found that especially in cases without any sign of prior inflammation, increasing the pulse width of the stimulation strategy seems to be an effective tool to return increased impedances to normal levels.

The influence of newborn hearing screening on the age at cochlear implantation in children

To evaluate the influence of the introduction of newborn hearing screening programs on the age at cochlear implantation in children.

Minimized rotational vestibular testing as a screening procedure detecting vestibular areflexy in deaf children: screening cochlear implant candidates for Usher syndrome type I.

Morbus Usher (USH), a combination of sensorineural hearing loss and retinal visual impairment, is classified into group I–III. USH I patients are born deaf. Within the first 10 years of life, they develop a severe vision impairment due to progressive retinal dystrophy (retinitis pigmentosa). USH I patients show vestibular deficits. The incidence of USH I among congenitally deaf children is assumed to be as high as 10%. We intend to create a simple examination procedure for screening congenitally deaf children for vestibular deficiency and subsequently USH I. The examination procedure is named “Minimized Rotation”. The vestibular function of deaf children was examined by Minimized Rotation during their preoperative cochlear implant candidacy examination. A lack of postrotational nystagmus was seen as an indication for vestibular deficit. Subsequently some of these patients were examined under general anaesthesia by electroretinography (ERG) at the Department of Ophthalmology. A total of 117 children were examined by Minimized Rotation. In 19 children (16.2%) no rotational nystagmus was found. Six of these children were additionally examined at the Department of Ophthalmology using Ganzfeld ERG. Three of them (50%) showed generalized dysfunction of the retina; 8.1% of the children undergoing preoperative evaluation for cochlear implatation are assumed to show abnormalities of the retina. Rotational examination seems to be an appropriate screening method to detect vestibular deficits, which is one sign of USH I. The results always have to be verified by Ganzfeld-ERG or further genetic investigations. Children with USH I are threatened by progressive reduction of vision. We, therefore, consider USH I children always to be implanted bilaterally with a cochlear implant to maximize the benefit of auditory rehabilitation.

Everyday listening questionnaire: Correlation between subjective hearing and objective performance

Abstract Objectives Clinical experience has demonstrated that speech understanding by cochlear implant (CI) recipients has improved over recent years with the development of new technology. The Everyday Listening Questionnaire 2 (ELQ 2) was designed to collect information regarding the challenges faced by CI recipients in everyday listening. The aim of this study was to compare self-assessment of CI users using ELQ 2 with objective speech recognition measures and to compare results between users of older and newer coding strategies. Methods During their regular clinical review appointments a group of representative adult CI recipients implanted with the Advanced Bionics implant system were asked to complete the questionnaire. The first 100 patients who agreed to participate in this survey were recruited independent of processor generation and speech coding strategy. Correlations between subjectively scored hearing performance in everyday listening situations and objectively measured speech perception abilities were examined relative to the speech coding strategies used. Results When subjects were grouped by strategy there were significant differences between users of older ‘standard’ strategies and users of the newer, currently available strategies (HiRes and HiRes 120), especially in the categories of telephone use and music perception. Significant correlations were found between certain subjective ratings and the objective speech perception data in noise. Conclusions There is a good correlation between subjective and objective data. Users of more recent speech coding strategies tend to have fewer problems in difficult hearing situations.