Andrea Kleine Punte

Cochlear implantation as a durable tinnitus treatment in single-sided deafness

Abstract Introduction Severe tinnitus can seriously impair patients in their activities in daily life and reduce their quality of life. The aims of this prospective clinical study were to assess the long-term effects of cochlear implantation (CI) on tinnitus in patients with single-sided deafness and ipsilateral incapacitating tinnitus, and to investigate whether CI could treat various types of tinnitus. Materials and methods Twenty-six subjects with unilateral severe-to-profound sensorineural hearing loss received a CI. Patients suffered from severe tinnitus greater than 6/10 on a visual analogue scale (VAS) due to unilateral deafness. Assessment consisted of a tinnitus analysis including determination of tinnitus type, frequency, and loudness. A tinnitus questionnaire (TQ) measured tinnitus distress. VAS and TQ were administered pre-implantation and post-implantation. Results All 26 patients reported a subjective benefit from CI. Tinnitus loudness reduced significantly after CI from 8.6 to 2.2 on the VAS (scale: 0–10). The TQ total score decreased significantly and the mean tinnitus degree decreased from severe to mild. No differences were observed between patients with pure-tone tinnitus, narrow band noise tinnitus, or polyphonic tinnitus. The degree of tinnitus loudness reduction remained stable after CI. Conclusions CI can successfully be used as treatment of severe tinnitus in patients with single-sided deafness and is equally effective for pure tone, narrow band noise, and polyphonic tinnitus. Long-term results show that implantation provides durable tinnitus relief in these patients. These results support the hypothesis that physiopathological mechanisms after peripheral deafferentation are reversible when hearing is restored. Single-sided deafness accompanied by severe tinnitus is a new indication for CI.

Prevalence of leisure noise-induced tinnitus and the attitude toward noise in university students

Background Adolescents and young adults often are exposed to potentially damaging loud music during leisure activities. As a consequence, more and more young adults suffer from tinnitus, hearing loss, and hyperacusis. The present study provides prevalence numbers for noise-induced tinnitus (NIT) in this group, the attitude toward loud music, and the factors influencing the use of hearing protection (HP). Method A questionnaire was undertaken to evaluate the influence of permanent/transient tinnitus after loud music, the attitudes toward noise, influence of peers, and the ability to manipulate HP on the use of HP. The questionnaire was completed by 145 university students. Results Approximately 89.5% of the students had experienced transient tinnitus after loud music exposure. The prevalence of transient NIT was higher in female subjects compared with male students. Permanent NIT was experienced by 14.8%. Nevertheless, few respondents were worried, and the degree of HP use was low (11%). However, the presence of permanent tinnitus was a motivation for HP use. Most respondents held a neutral to positive attitude (i.e., pronoise) toward loud music and were not fully aware of the risks of too much noise exposure. Conclusion NIT is a common phenomenon among young adults. The lack of knowledge in young adults and the underuse of HP in leisure activities provide useful information to refine preventive measures in the future.

Neural substrates predicting improvement of tinnitus after cochlear implantation in patients with single-sided deafness

Notwithstanding successful reduction of tinnitus after cochlear implantation (CI) in patients with single-sided deafness (SSD) in recent studies, neither the exact mechanism of suppression nor the predictors of the amount of improvement are fully understood yet. We collected quantitative electroencephalography (qEEG) data from nine SSD patients who underwent CI for tinnitus management. By correlating the degree of improvement in tinnitus intensity and tinnitus-related distress with preoperative source-localized qEEG findings and comparing qEEG findings of patients with marked improvement after CI with those with relatively slight improvement with regard to source-localized activity complimented by connectivity analysis, we attempted to find preoperative predictors of tinnitus improvement. Our results showed increased activities of the auditory cortex (AC), posterior cingulate cortex (PCC) and increased functional connectivity between the AC and PCC as negative prognostic factors for the reduction of tinnitus intensity after CI in patients with SSD. Also, relatively increased activity of the right dorsolateral prefrontal cortex and decreased connectivity between distress-related areas such as the orbitofrontal cortex/parahippocampus and sensory-perception areas such as the AC/precuneus were found in patients with relatively slight improvement in tinnitus-related distress as compared with those with marked improvement. The current study suggests that preoperative cortical oscillations can be applied to predict post-CI tinnitus reduction in patients with SSD.

Better Speech Recognition in Noise with the Fine Structure Processing Coding Strategy

Background: Recently, a new speech coding strategy named ‘fine structure processing’ (FSP) has been launched. Methods: 32 subjects, all users of the MED-EL PULSARCI100 system, have been switched over from a TEMPO+ to an OPUS 2 speech processor. In 22 subjects, the FSP strategy could be implemented (FSP group), in 10 patients not (high-definition continuous interleaved sampling, HDCIS, group). Subjects were tested with the Tempo+ (CIS+) just before switch-over and after 12 months of OPUS 2 (FSP/HDCIS) use. Performance with FSP/HDCIS was tested at switch-over, and after 1, 3, 6 and 12 months. A sentence-in-noise test and a Speech Spatial and Qualities of Hearing Scale (SSQ) questionnaire were assessed at each test interval. Results: In the FSP group, the speech reception threshold shows a deterioration of 3.3 dB (n.s.) at the acute switch-over interval, but a significant improvement over time (p < 0.001) with a final benefit of 6.5 dB after 12 months of FSP use. A significant improvement over time can also be seen on the spatial subscore of the SSQ questionnaire (p = 0.009). No significant differences could be seen in the HDCIS group. Conclusion: The results show that by enhancing fine structure coding in the lower frequencies, as implemented in the FSP coding strategy, speech perception in noise can be enhanced.

Frequency-place map for electrical stimulation in cochlear implants: Change over time

The relationship between the place of electrical stimulation from a cochlear implant and the corresponding perceived pitch remains uncertain. Previous studies have estimated what the pitch corresponding to a particular location should be. However, perceptual verification is difficult because a subject needs both a cochlear implant and sufficient residual hearing to reliably compare electric and acoustic pitches. Additional complications can arise from the possibility that the pitch corresponding to an electrode may change as the auditory system adapts to a sound processor. In the following experiment, five subjects with normal or near-to-normal hearing in one ear and a cochlear implant with a long electrode array in the other ear were studied. Pitch matches were made between single electrode pulse trains and acoustic tones before activation of the speech processor to gain an estimate of the pitch provided by electrical stimulation at a given insertion angle without the influence of exposure to a sound processor. The pitch matches were repeated after 1, 3, 6, and 12 months of experience with the sound processor to evaluate the effect of adaptation over time. Pre-activation pitch matches were lower than would be estimated by a spiral ganglion pitch map. Deviations were largest for stimulation below 240° degrees and smallest above 480°. With experience, pitch matches shifted towards the frequency-to-electrode allocation. However, no statistically significant pitch shifts were observed over time. The likely explanation for the lack of pitch change is that the frequency-to-electrode allocations for the long electrode arrays were already similar to the pre-activation pitch matches. Minimal place pitch shifts over time suggest a minimal amount of perceptual remapping needed for the integration of electric and acoustic stimuli, which may contribute to shorter times to asymptotic performance.

Binaural auditory outcomes in patients with postlingual profound unilateral hearing loss: 3 years after cochlear implantation.

The value of cochlear implants (CI) in patients with profound unilateral hearing loss (UHL) and tinnitus has recently been investigated. The authors previously demonstrated the feasibility of CI in a 12- month outcome study in a prospective UHL cohort. The aim of this study was to investigate the binaural auditory outcomes in this cohort 36 months after CI surgery. The 36-month outcome was evaluated in 22 CI users with postlingual UHL and severe tinnitus. Twelve subjects had contralateral normal hearing (single-sided deafness - SSD group) and 10 subjects had a contralateral, mild to moderate hearing loss and used a hearing aid (asymmetric hearing loss - AHL group). Speech perception in noise was assessed in two listening conditions: the CIoff and the CIon condition. The binaural summation effect (S₀N₀), binaural squelch effect (S₀NCI) and the combined head shadow effect (SCIN₀) were investigated. Subjective benefit in daily life was assessed by means of the Speech, Spatial and Qualities of Hearing Scale (SSQ). At 36 months, a significant binaural summation effect was observed for the study cohort (2.00, SD 3.82 dB; p < 0.01) and for the AHL subgroup (3.34, SD 5.31 dB; p < 0.05). This binaural effect was not significant 12 months after CI surgery. A binaural squelch effect was significant for the AHL subgroup at 12 months (2.00, SD 4.38 dB; p < 0.05). A significant combined head shadow and squelch effect was also noted in the spatial configuration SCIN₀ for the study cohort (4.00, SD 5.89 dB; p < 0.01) and for the AHL subgroup (5.67, SD 6.66 dB; p < 0.05). The SSQ data show that the perceived benefit in daily life after CI surgery remains stable up to 36 months at CIon. CI can significantly improve speech perception in noise in patients with UHL. The positive effects of CIon speech perception in noise increase over time up to 36 months after CI surgery. Improved subjective benefit in daily life was also shown to be sustained in these patients.

On the necessity of full length electrical cochlear stimulation to suppress severe tinnitus in single-sided deafness

BACKGROUND Cochlear implantation (CI) has proven in long term prospective trials to reduce significantly incapacitating tinnitus in single sided deafness (SSD). Discussion arises whether electrical stimulation near the round window (RW) is also able to reduce tinnitus. AIM to assess whether electrical stimulation of the basal first 4 intracochlear electrodes of a CI could sufficiently reduce tinnitus and to compare these results with stimulation with all CI electrodes. MATERIAL AND METHODS 7 patients who met the criteria of severe tinnitus due to SSD were implanted with a Med-El Sonata Ti100 with a FlexSoftTM or Flex24TM electrode. After 4 weeks only the basal electrode pair (E12) nearest to the RW was activated. Each week the following pair was activated until the 4th pair.Thereafter all electrodes were activated. Tinnitus was assessed before CI surgery and before each electrode pair was activated. When all electrodes were fitted, evaluation was done after 1, 3 and 6 months.Tinnitus was assessed with Visual Analogue Scale (VAS) for loudness, psychoacoustic tinnitus loudness comparison at 1 kHz and Tinnitus Questionnaire (TQ) for the effect on quality of life. To evaluate the natural evolution, a tightly matched control group with severe tinnitus due to SSD was followed prospectively. RESULTS All the tinnitus outcome measures remained unchanged with 1, 2, 3 or 4 activated electrode pairs. With complete CI activation, the tinnitus decreased significantly comparable with earlier reports.Pre-implantation the tinnitus loudness was 8.2/10 on the VAS and was reduced to 4.1/10 6 months postimplantation.Psychometrically the loudness level went from 21.7 dB SL (SD: 16.02) to 7.5 dB SL (SD: 5.24)and the TQ from 60/84 to 39/84. The non-implanted group had no decrease of the tinnitus, the average VAS remained stable at 8.9/10 throughout the follow-up period of 6 months. CONCLUSION with the current stimulation parameters electrical stimulation in the first 8e10 mm of the basal part of the scala tympani is insufficient to reduce tinnitus. However, stimulation over the complete CI length yields immediate tinnitus reduction confirming earlier results.

Long-term follow-up of hearing preservation in electric-acoustic stimulation patients.

Background Hearing preservation (HP) surgery was initiated more than 10 years ago for combined electric and acoustic stimulation (EAS). Preserved residual low-frequency hearing has been demonstrated to improve speech perception in noise as well as music appreciation in EAS users up to 2 years. Multiple study groups aimed to evaluate initial loss of residual hearing (RH) as a consequence of HP surgery. However, after 1 year and 2 years of follow-up, further decline was reported. This study aimed to determine RH, speech perception, and the subjective benefits of EAS 10 years after HP surgery. Subjects and Methods Nine postlingual EAS partially deaf patients who underwent HP surgery at Antwerp University Hospital were included in this study (11 implanted ears). Hearing preservation (0% = loss of hearing; >0%–25% = minimal HP; >25%–75% = partial HP; >75% = complete HP), speech perception and subjective benefits were evaluated preoperatively; at 3, 6, 12, 18, and 24 months postoperatively; and annually thereafter. Results Complete HP was obtained in three of 11 ears; partial HP in five of 11 ears; and minimal HP in two of 11 ears, measured during their most recent follow-up. One subject lost his RH completely across time. The mean rate of HP was 48% (ranging from 6 months up to 10 years postoperatively). Speech perception analysis up to 10 years showed a continuous statistically significant improvement. The maximum subjective benefit was reached 3 months after implantation and subsequently remained statistically significant unchanged for the next 10 years. Conclusion Long-term HP in EAS users after HP surgery is feasible, although a small continuous decline of HP rate of 3% per year was observed (measured from first fitting up to 6 years postoperative). Nevertheless, a continuous improvement was found in the speech perception results of the EAS users across 10 years. Moreover, the positive subjective benefit, assessed 3 months postoperative, remained stable up to 10 years.

Perceptual changes in place of stimulation with long cochlear implant electrode arrays

Long (31.5 mm) electrode arrays are inserted deeper into the cochlea than the typical 1.25 turn insertion. With these electrode arrays, the apical electrodes are closer to (and possibly extend past) the end of the spiral ganglion. Using multi-dimensional scaling with patients implanted with a 31.5 mm electrode array, the perceptual space between electrodes was measured. The results suggest that deeper insertion increases the range of place pitches, but the perceptual differences between adjacent electrodes become smaller in the apex.

Long-Term Improvement of Speech Perception with the Fine Structure Processing Coding Strategy in Cochlear Implants

AIMS To investigate the long-term effects of the fine structure processing (FSP) coding strategy on speech perception in noise and quality of life in experienced cochlear implant (CI) users. METHODS In a prospective comparative clinical trial, 32 experienced postlingually deafened CI recipients were upgraded from the Tempo+ to the Opus 2 audio processor, implementing FSP in one group and high-definition continuous interleaved sampling (HDCIS) coding strategy in another group with identical frequency ranges. Speech perception in noise testing and the Speech, Spatial and Qualities (SSQ) questionnaire were administered at 0, 6, 12 and 24 months after the upgrade. RESULTS FSP yielded significant long-term improvement of speech perception in noise of in total 13.2 dB from 16.2 dB SNR at the upgrade to 3.0 dB SNR after 24 months of FSP experience. No significant improvement of speech perception in noise over time was measured for the HDCIS group. With the SSQ questionnaire, a significant benefit of the FSP coding strategy was observed. CONCLUSIONS The FSP coding strategy as implemented in the Med-EL Opus 2 audio processor improves speech perception in noise. This beneficial effect of FSP on speech perception in noise is not immediate but is significant after 12 months and further improves up to 24 months after implementation of FSP.Aims: To investigate the long-term effects of the fine structure processing (FSP) coding strategy on speech perception in noise and quality of life in experienced cochlear implant (CI) users. Methods: In a prospective comparative clinical trial, 32 experienced postlingually deafened CI recipients were upgraded from the Tempo+ to the Opus 2 audio processor, implementing FSP in one group and high-definition continuous interleaved sampling (HDCIS) coding strategy in another group with identical frequency ranges. Speech perception in noise testing and the Speech, Spatial and Qualities (SSQ) questionnaire were administered at 0, 6, 12 and 24 months after the upgrade. Results: FSP yielded significant long-term improvement of speech perception in noise of in total 13.2 dB from 16.2 dB SNR at the upgrade to 3.0 dB SNR after 24 months of FSP experience. No significant improvement of speech perception in noise over time was measured for the HDCIS group. With the SSQ questionnaire, a significant benefit of the FSP coding strategy was observed. Conclusions: The FSP coding strategy as implemented in the Med-EL Opus 2 audio processor improves speech perception in noise. This beneficial effect of FSP on speech perception in noise is not immediate but is significant after 12 months and further improves up to 24 months after implementation of FSP.