Gijsbert A. van Zanten

Socio-demographic, health, and tinnitus related variables affecting tinnitus severity.

Objectives: Tinnitus is a highly prevalent symptom with potential severe morbidity. Fortunately, only a small proportion of the population experience problems due to their tinnitus in such a degree that it adversely affects their quality of life (clinically significant tinnitus). It is not known why these individuals develop more burden from tinnitus. It seems likely that the severity of tinnitus can be influenced by different factors, such as socio-demographic or tinnitus characteristics or additional health complaints. It remains unclear from the current literature as to what are the main independent variables that have a bearing on tinnitus severity. This study addresses this problem by investigating variables previously described in the literature as well as additional variables. The aim of this study is to identify socio-demographic, health, and tinnitus variables that independently relate to tinnitus severity the most. Design: This is a retrospective cohort study performed at the Tinnitus Care Group of the University Medical Center, Utrecht, in 309 consecutively seen chronic tinnitus patients. At this care group, patients are examined according to a structured diagnostic protocol, including history-taking by an otorhinolaryngologist and audiologist, physical examination, and audiometry. Based on results from previous research and theoretical considerations, a subset of data acquired through this diagnostic protocol were selected and used in this study. Univariate and multivariate correlations with tinnitus severity were investigated for 28 socio-demographic, health, and tinnitus variables. Tinnitus severity was measured with the Tinnitus Questionnaire (TQ) and the Tinnitus Handicap Inventory (THI). Results: Eighteen variables related univariately with the TQ and 16 variables related univariately with the THI. Among these, 14 variables related univariately with both the TQ and the THI. Multivariate analyses showed three variables with an independent significant effect on both the TQ and the THI: percentage of tinnitus awareness during the day, self-reported depression and/or anxiety, and loudness on a Visual Analogue Scale. Three additional variables contributed independently significantly to the explained variance in either the TQ or the THI: level of education, somatic complaints, and tinnitus variability in loudness and/or pitch on a Visual Analogue Scale. These variables were among the first not to reach significance on the other questionnaire. Conclusions: Tinnitus severity is shown to be strongly related to percentage of tinnitus awareness during the day, self-reported depression and/or anxiety, subjectively experienced loudness, level of education, existence of additional somatic complaints, and subjectively experienced variability in loudness and/or pitch. Further research is needed to investigate the causal relationship between these variables and tinnitus severity. This knowledge may contribute to a better recognition, follow-up, and/or counseling of more vulnerable patients.

Bilateral Low-Frequency Repetitive Transcranial Magnetic Stimulation of the Auditory Cortex in Tinnitus Patients Is Not Effective: A Randomised Controlled Trial

Background: Although some therapies may be beneficial for some patients in reducing tinnitus, there is no curative therapy. Repetitive transcranial magnetic stimulation (rTMS) has been applied as a treatment for chronic tinnitus, but the effect remains controversial. Material and Methods: Fifty patients were treated with rTMS or placebo. Treatment consisted of 2,000 TMS pulses on each auditory cortex, at a rate of 1 Hz and an intensity of 110% of the individual motor threshold, on 5 consecutive days. rTMS and placebo effects were evaluated directly after treatment, after 1 week, and after 1, 3 and 6 months. Primary outcome was the Tinnitus Questionnaire (TQ). Secondary outcomes were the Tinnitus Handicap Inventory (THI) and a visual analogue scale. Results: At none of the follow-up evaluation moments a significant difference between rTMS and placebo was observed with respect to changes in TQ or THI scores relative to pretreatment scores. Multilevel modelling (MLM) analyses did not show a global treatment effect either. Patients with a higher degree of burden showed slightly greater improvement after rTMS (only significant on the THI with MLM analyses). Conclusion: Bilateral low-frequency rTMS of the auditory cortex was not effective in treating tinnitus.

What is the effect of time between sequential cochlear implantations on hearing in adults and children? A systematic review of the literature

Bilateral cochlear implantation is a safe and effective intervention for severe sensorineural hearing loss and is believed to be more effective than unilateral implantation. This review article investigates the effect of time between sequential cochlear implantations on hearing results in both adults and children.

Altered cortical activity in prelingually deafened cochlear implant users following long periods of auditory deprivation.

Auditory stimulation during childhood is critical for the development of the auditory cortex in humans and with that for hearing in adulthood. Age-related changes in morphology and peak latencies of the cortical auditory evoked potential (CAEP) have led to the use of this cortical response as a biomarker of auditory cortical maturation including studies of cortical development after deafness and subsequent cochlear implantation. To date, it is unknown whether prelingually deaf adults, with early onset deafness (before the age of 2 years) and who received a cochlear implant (CI) only during adulthood, would display absent or aberrant CAEP waveforms as predicted from CAEP studies in late implanted prelingually deaf children. In the current study, CAEP waveforms were recorded in response to electric stimuli in prelingually deaf adults, who received their CI after the age of 21 years. Waveform morphology and peak latencies were compared to the CAEP responses obtained in postlingually deaf adults, who became deaf after the age of 16. Unexpectedly, typical CAEP waveforms with adult-like P1-N1-P2 morphology could be recorded in the prelingually deaf adult CI users. On visual inspection, waveform morphology was comparable to the CAEP waveforms recorded in the postlingually deaf CI users. Interestingly, however, latencies of the N1 peak were significantly shorter and amplitudes were significantly larger in the prelingual group than in the postlingual group. The presence of the CAEP together with an early and large N1 peak might represent activation of the more innate and less complex components of the auditory cortex of the prelingually deaf CI user, whereas the CAEP in postlingually deaf CI users might reflect activation of the mature neural network still present in these patients. The CAEPs may therefore be helpful in the assessment of developmental state of the auditory cortex.

Effect of unilateral and simultaneous bilateral cochlear implantation on tinnitus: A Prospective Study.

To determine the effect of cochlear implantation on tinnitus perception in patients with severe bilateral postlingual sensorineural hearing loss and to demonstrate possible differences between unilateral and bilateral cochlear implantation.

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.

Stable benefits of bilateral over unilateral cochlear implantation after two years: A randomized controlled trial

To investigate hearing capabilities and self‐reported benefits of simultaneous bilateral cochlear implantation (BiCI) compared with unilateral cochlear implantation (UCI) after a 2‐year follow‐up and to evaluate the learning effect of cochlear implantees over time.

Validation of the U-STARR with the AB-York crescent of sound, a new instrument to evaluate speech intelligibility in noise and spatial hearing skills

The Advanced Bionics® (AB)-York crescent of sound is a new test setup that comprises speech intelligibility in noise and localization tests that represent everyday listening situations. One of its tests is the Sentence Test with Adaptive Randomized Roving levels (STARR) with sentences and noise both presented from straight ahead. For the Dutch population, we adopted the AB-York setup and replaced the English sentences with a validated set of Dutch sentences. The Dutch version of the STARR is called the Utrecht-STARR (U-STARR). This study primarily assesses the validity and reliability of the U-STARR compared to the Plomp test, which is the current Dutch gold standard for speech-in-noise testing. The outcome of both tests is a speech reception threshold in noise (SRTn). Secondary outcomes are the SRTn measured with sounds from spatially separated sources (SISSS) as well as sound localization capability. We tested 29 normal-hearing adults and 18 postlingually deafened adult patients with unilateral cochlear implants (CI). This study shows that the U-STARR is adequate and reliable and seems better suited for severely hearing-impaired persons than the conventional Plomp test. Further, CI patients have poor spatial listening skills, as demonstrated with the AB-York test.

Cost-Utility of Bilateral Versus Unilateral Cochlear Implantation in Adults: A Randomized Controlled Trial

Objective: To study the cost–utility of simultaneous bilateral cochlear implantation (CI) versus unilateral CI. Study Design: Randomized controlled trial (RCT). Setting: Five tertiary referral centers. Patients: Thirty-eight postlingually deafened adults eligible for cochlear implantation. Interventions: A cost–utility analysis was performed from a health insurance perspective. Main Outcome Measures: Utility was assessed using the HUI3, TTO, VAS on hearing, VAS on general health and EQ-5D. We modeled the incremental cost per quality-adjusted life year (QALY) of unilateral versus bilateral CI over periods of 2, 5, 10, 25 years, and actual life-expectancy. Results: Direct costs for unilateral and bilateral CI were &OV0556;43,883 ± &OV0556;11,513(SD) and &OV0556;87,765 ± &OV0556;23,027(SD) respectively. Annual costs from the second year onward were &OV0556;3,435 ± &OV0556;1,085(SD) and &OV0556;6,871 ± &OV0556;2,169(SD), respectively. A cost–utility analysis revealed that a second implant became cost-effective after a 5- to 10-year period, based on the HUI3, TTO, and VAS on hearing. Conclusion: This is the first study that describes a cost–utility analysis to compare unilateral with simultaneous bilateral CI in postlingually deafened adults, using a multicenter RCT. Compared with accepted societal willingness-to-pay thresholds, simultaneous bilateral CI is a cost-effective treatment for patients with a life expectancy of 5–10 years or longer.

Development of a Squelch Effect in Adult Patients After Simultaneous Bilateral Cochlear Implantation

Objectives: To investigate whether a squelch effect occurs in the first 3 years after simultaneous bilateral cochlear implantation and to investigate whether this effect increases during follow-up. Study Design: Prospective study as part of a multicenter randomized controlled trial that compares simultaneous bilateral cochlear implantation to sequential and unilateral cochlear implantation. Setting: Tertiary referral center. Patients: Nineteen postlingually deafened adults. Intervention: Simultaneous bilateral cochlear implantation. Main Outcome Measure: The squelch effect, measured yearly with a speech-intelligibility-in-noise test with spatially separated sources. Bilateral results were compared to unilateral results in which the cochlear implant at the noise side was turned off. The squelch effect was investigated for the patients’ best performing ear and for the left and right ears separately. Results: In 13 individual patients, a squelch effect was present after 1 year. This number increased during follow-up years. On group level, a squelch effect was present in patients’ best performing ear after 2 and 3 years (1.9 dB). A squelch effect was present in both ears after 3 years (AS: 1.7 dB, AD: 1.3 dB). Conclusion: Patients who underwent simultaneous bilateral cochlear implantation developed a measurable benefit from the squelch effect after 2 years in their best performing ear and after 3 years in both ears. These observations suggest that the brain learns to use interaural differences to segregate sound from noise after simultaneous bilateral cochlear implantation. The squelch effect increased over time which suggests a growth in cortical integration and differentiation of inputs from bilateral CIs due to brain plasticity. Trial Registration: Dutch Trial Register NTR1722. Level of evidence: 1b.