Identifying non-otologic risk factors for tinnitus: A systematic review.

BACKGROUND: The origin of tinnitus has been attributed to a peripheral auditory lesion, inducing bottom-up changes and resulting in the perception of a "phantom sound." However, non-auditory factors can co-exist as well, and can even lie at the origin of tinnitus development. An increasing body of literature focuses on psychological, (neuro)muscular, cardiovascular and many other influences and their respective associations with tinnitus prevalence. OBJECTIVE OF REVIEW: The purpose of this study was to provide a comprehensive description of these non-otologic risk factors, and to summarise the evidence in literature about their link with tinnitus. TYPE OF REVIEW: A narrative systematic review was conducted, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. SEARCH STRATEGY: The MEDLINE, Embase and Web of Science databases were systematically searched for eligible articles, supplemented with manual search methods and grey literature search. Epidemiological studies reporting on the relationship between various non-otologic risk factors and tinnitus were included. EVALUATION METHOD: Quality assessment was performed using the Hoy & Brooks tool. RESULTS: Fifty-five studies were included. Studies were of variable quality, with poor tinnitus definitions and evaluations or questionable sampling of the study population as main contributing factors for high risk of bias. Multiple associated factors have been identified, including cardiovascular, psychological, neurological, musculoskeletal and dietary factors. CONCLUSIONS: The current literature review identified multiple risk factors that could be of significant importance for tinnitus development, maintenance or aggravation. While causality remains uncertain, this systematic elaboration of possible tinnitus comorbidities/risk factors can help provide direction for future research, and can direct clinicians to identify patients at risk and treat relevant symptoms accordingly.

Invasive Neuromodulation as a Treatment for Tinnitus: A Systematic Review.

OBJECTIVE: Although the prevalence and burden of tinnitus is high, none of the available tinnitus treatments has been proven to be effective for the majority of tinnitus patients so far. Neuromodulation is currently gaining more interest to explore as tinnitus treatment. Because noninvasive neuromodulation has been shown to be effective in some tinnitus patients in the short term, more invasive techniques have been applied with variable success and without clear clinical applicability. As new insights into the neuropathophysiology of tinnitus arise, it seems essential to recapitulate the current evidence of invasive neuromodulation for tinnitus, to assess the quality of the available studies and identify gaps in this research domain. DATA SOURCES: MEDLINE, Embase, Web of Science and Clinical Trial Register. MATERIALS AND METHODS: We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Studies since 2005 that reported on adult human subjects with chronic subjective tinnitus, who underwent some form of invasive neuromodulation, were included. Quality evaluation was performed using the modified Downs and Black checklist. RESULTS AND CONCLUSION: Twenty-one studies were included. Studies were often of low quality due to low sample sizes, lack of controlled designs, or investigating tinnitus as a secondary indication of neuromodulation. Current research results provide insufficient evidence to generally recommend invasive neuromodulation as an alternative treatment alternative for intractable tinnitus, although some promising effects are mentioned. Further research must be encouraged to gain more insight in this treatment including optimization of the technique, and standardization of tinnitus evaluation in subgroups.

The P300 auditory event-related potential as a method to assess the benefit of contralateral hearing aid use in bimodal listeners: a proof-of-concept.

Objective: Bimodal listeners vary in the amount of benefit they receive from wearing the contralateral hearing aid. This may partially depend on the listener's auditory processing capacities. The current study explores whether the P300 event-related potential can provide insight into the mechanisms underlying the benefits of wearing a contralateral hearing aid.Design: P300s were recorded using an oddball paradigm with 500 and 250 Hz tone-bursts as standard and deviant stimuli, respectively. Subjects counted the number of deviants - a measure of performance. N2b latencies, P300 latencies, N2b-P300 amplitudes, and performance were assessed during CI-only and bimodal listening.Study sample: Five bimodal listeners.Results: P300s were present in four subjects. Amplitudes were larger during bimodal listening (bimodal: 22.3 ± 4.83 µV, CI-only: 13.1 ± 3.86 µV). Both N2b and P300 latencies were shorter during bimodal (N2b: 265 ± 20.0 ms, P300: 551 ± 129.4 ms) than CI-only listening (N2b: 326 ± 42.2 ms, P300: 402 ± 38.4 ms). While performance often reached ceiling level, the difference between the standard and deviant was generally more salient during bimodal listening.Conclusions: This study provides a proof-of-concept, suggesting that P300s may provide insight into benefits that are not always measurable with behavioural tasks.

Test-Retest Reproducibility of Response Duration in Tinnitus Patients With Positive Residual Inhibition.

Purpose Functional imaging is often used to try to elucidate the pathophysiological mechanism of tinnitus. Residual inhibition, the temporary suppression of tinnitus after application of a masking noise, could be an interesting technique to modulate tinnitus perception in functional imaging paradigms. The purposes of this study were to primarily assess reproducibility of the (partial) positive residual inhibition response duration in patients with tinnitus and to explore its utility in experimental designs. Method Patients with tinnitus exhibiting a (partial) positive residual inhibition response or tinnitus reduction after a 1-min white noise presentation were selected from a broad consulting tinnitus population. In 27 patients, this response was tested 4 times: twice during initial testing and twice during a retest of the psychoacoustic tinnitus measures, 4-8 weeks after initial consultation. In 17 patients with stable residual inhibition responses, reproducibility of response duration, the duration of tinnitus reduction up to pretesting state, was analyzed. Results Initial testing showed a residual inhibition duration of 29.5 s on average. Test-retest reproducibility of response duration was shown to be reliable with an ICC(3, 4) of .871 (95% CI [0.733, 0.948]) and a standard error of measurement of 6.64 s. Conclusions This study indicates the good test-retest reproducibility of residual inhibition duration in our subset of 17 patients with stable (partial) positive residual inhibition. Residual inhibition is, therefore, a technique that can potentially be used for temporary tinnitus manipulation in experimental paradigms to unravel tinnitus pathophysiology.

Bilateral cochlear implantation or bimodal listening in the paediatric population: Retrospective analysis of decisive criteria.

INTRODUCTION: In children with bilateral severe to profound hearing loss, bilateral hearing can be achieved by either bimodal stimulation (CIHA) or bilateral cochlear implantation (BICI). The aim of this study was to analyse the audiologic test protocol that is currently applied to make decisions regarding the bilateral hearing modality in the paediatric population. METHODS: Pre- and postoperative audiologic test results of 21 CIHA, 19 sequential BICI and 12 simultaneous BICI children were examined retrospectively. RESULTS: Deciding between either simultaneous BICI or unilateral implantation was mainly based on the infant's preoperative Auditory Brainstem Response thresholds. Evolution from CIHA to sequential BICI was mainly based on the audiometric test results in the contralateral (hearing aid) ear after unilateral cochlear implantation. Preoperative audiometric thresholds in the hearing aid ear were significantly better in CIHA versus sequential BICI children (p < 0.001 and p = 0.001 in unaided and aided condition, respectively). Decisive values obtained in the hearing aid ear in favour of BICI were: An average hearing threshold measured at 0.5, 1, 2 and 4 kHz of at least 93 dB HL without, and at least 52 dB HL with hearing aid together with a 40% aided speech recognition score and a 70% aided score on the phoneme discrimination subtest of the Auditory Speech Sounds Evaluation test battery. CONCLUSIONS: Although pure tone audiometry offers no information about bimodal benefit, it remains the most obvious audiometric evaluation in the decision process on the mode of bilateral stimulation in the paediatric population. A theoretical test protocol for adequate evaluation of bimodal benefit in the paediatric population is proposed.

Phenotype of a Belgian Family With 6p25 Deletion Syndrome.

BACKGROUND: The 6p25 deletion syndrome is one of the many syndromes with both hearing impairment as well as vision impairment. However, the audiometric characteristics and radiological findings of patients with 6p25 deletions are only scarcely described in literature. This study focused on characterizing the audiometric and radiological features of a Belgian family with a chromosome 6p25 deletion. OBJECTIVE: To evaluate the hearing impairment, audiometric testing and radiological examination of the temporal bones in 3 family members with a 3.4 Mb deletion in chromosome band 6p25. RESULTS: All 3 family members demonstrated slowly progressive sensorineural or mixed hearing impairment. Radiologic examination revealed thickened and sclerotic stapes in all patients and a minor internal partition type II of the cochlea in 2 patients. CONCLUSION: There is a significant phenotypic variability within and among families with the 6p25 deletion syndrome. A thorough genotype-phenotype correlation is difficult because of the small number of affected patients and the limited clinical data available. More clinical data of families with 6p25 deletions need to be published in order to create a reliable and precise phenotypic characterization. However, our findings can facilitate counseling of hearing impairment caused by 6p25 deletions.

Age-Related Changes in Binaural Interaction at Brainstem Level.

OBJECTIVES: Age-related hearing loss hampers the ability to understand speech in adverse listening conditions. This is attributed to a complex interaction of changes in the peripheral and central auditory system. One aspect that may deteriorate across the lifespan is binaural interaction. The present study investigates binaural interaction at the level of the auditory brainstem. It is hypothesized that brainstem binaural interaction deteriorates with advancing age. DESIGN: Forty-two subjects of various age participated in the study. Auditory brainstem responses (ABRs) were recorded using clicks and 500 Hz tone-bursts. ABRs were elicited by monaural right, monaural left, and binaural stimulation. Binaural interaction was investigated in two ways. First, grand averages of the binaural interaction component were computed for each age group. Second, wave V characteristics of the binaural ABR were compared with those of the summed left and right ABRs. RESULTS: Binaural interaction in the click ABR was demonstrated by shorter latencies and smaller amplitudes in the binaural compared with the summed monaural responses. For 500 Hz tone-burst ABR, no latency differences were found. However, amplitudes were significantly smaller in the binaural than summed monaural condition. An age-effect was found for 500 Hz tone-burst, but not for click ABR. CONCLUSIONS: Brainstem binaural interaction seems to decline with age. Interestingly, these changes seem to be stimulus-dependent.

Binaural interaction in the auditory brainstem response: a normative study.

OBJECTIVE: Binaural interaction can be investigated using auditory evoked potentials. A binaural interaction component can be derived from the auditory brainstem response (ABR-BIC) and is considered evidence for binaural interaction at the level of the brainstem. Although click ABR-BIC has been investigated thoroughly, data on 500 Hz tone-burst (TB) ABR-BICs are scarce. In this study, characteristics of click and 500 Hz TB ABR-BICs are described. Furthermore, reliability of both click and 500 Hz TB ABR-BIC are investigated. METHODS: Eighteen normal hearing young adults (eight women, ten men) were included. ABRs were recorded in response to clicks and 500 Hz TBs. ABR-BICs were derived by subtracting the binaural response from the sum of the monaural responses measured in opposite ears. RESULTS: Good inter-rater reliability is obtained for both click and 500 Hz TB ABR-BICs. The most reliable peak in click ABR-BIC occurs at a mean latency of 6.06 ms (SD 0.354 ms). Reliable 500 Hz TB ABR-BIC are obtained with a mean latency of 9.47 ms (SD 0.678 ms). Amplitudes are larger for 500 Hz TB ABR-BIC than for clicks. CONCLUSION: The most reliable peak in click ABR-BIC occurs at the downslope of wave V. Five hundred Hertz TB ABR-BIC is characterized by a broad positivity occurring at the level of wave V. SIGNIFICANCE: The ABR-BIC is a useful technique to investigate binaural interaction in certain populations. Examples are bilateral hearing aid users, bilateral cochlear implant users and bimodal listeners. The latter refers to the combination of unilateral cochlear implantation and contralateral residual hearing. The majority of these patients have residual hearing in the low frequencies. The current study suggests that 500 Hz TB ABR-BIC may be a suitable technique to assess binaural interaction in this specific population of cochlear implant users.

Temporal bone imaging in osteogenesis imperfecta patients with hearing loss.

OBJECTIVES/HYPOTHESIS: Osteogenesis imperfecta (OI) is an autosomal-dominant connective-tissue disorder, predominantly characterized by bone fragility. Conductive hearing loss develops in half of the OI patients and often progresses to mixed loss. Findings of computed tomography (CT) and magnetic resonance (MR) imaging of the temporal bone in the largest series of OI patients to date are presented and correlated with the audiograms. STUDY DESIGN: Retrospective case series. METHODS: CT images and audiograms of 17 hearing-impaired OI patients, aged 9 to 67 years, were analyzed retrospectively. In four patients, MR imaging was performed as well. Imaging abnormalities were correlated with type and severity of hearing loss deduced from the audiograms. RESULTS: CT revealed fenestral hypodense foci in the fissula ante fenestram (25 of 33 ears), oval window (23 of 33 ears), and round window (20 of 33 ears). Retrofenestral hypodensities were observed, affecting the cochlear turns (16 of 33 ears), facial nerve canal (10 of 33 ears), or semicircular canals (6 of 33 ears), or appearing like the fourth turn of the cochlea (11 of 33 ears). The site of hypodensities corresponded to the type of hearing loss in 72.2% of the OI ears. The air-bone gap and bone-conduction thresholds showed significant positive associations with the number of affected fenestral (P < .05) and retrofenestral structures (P < .01), respectively. Gadolinium-enhanced MR images demonstrated active lesions in three patients with mixed hearing loss or deafness. CONCLUSIONS: The site of hypodensities on temporal bone CT images in OI corresponds to presence and type of hearing loss determined by audiometry. The more severe the hearing loss, the more affected temporal bone structures in OI.

Hearing impairment in Stickler syndrome: a systematic review.

BACKGROUND: Stickler syndrome is a connective tissue disorder characterized by ocular, skeletal, orofacial and auditory defects. It is caused by mutations in different collagen genes, namely COL2A1, COL11A1 and COL11A2 (autosomal dominant inheritance), and COL9A1 and COL9A2 (autosomal recessive inheritance). The auditory phenotype in Stickler syndrome is inconsistently reported. Therefore we performed a systematic review of the literature to give an up-to-date overview of hearing loss in Stickler syndrome, and correlated it with the genotype. METHODS: English-language literature was reviewed through searches of PubMed and Web of Science, in order to find relevant articles describing auditory features in Stickler patients, along with genotype. Prevalences of hearing loss are calculated and correlated with the different affected genes and type of mutation. RESULTS: 313 patients (102 families) individually described in 46 articles were included. Hearing loss was found in 62.9%, mostly mild to moderate when reported. Hearing impairment was predominantly sensorineural (67.8%). Conductive (14.1%) and mixed (18.1%) hearing loss was primarily found in young patients or patients with a palatal defect. Overall, mutations in COL11A1 (82.5%) and COL11A2 (94.1%) seem to be more frequently associated with hearing impairment than mutations in COL2A1 (52.2%). CONCLUSIONS: Hearing impairment in patients with Stickler syndrome is common. Sensorineural hearing loss predominates, but also conductive hearing loss, especially in children and patients with a palatal defect, may occur. The distinct disease-causing collagen genes are associated with a different prevalence of hearing impairment, but still large phenotypic variation exists. Regular auditory follow-up is strongly advised, particularly because many Stickler patients are visually impaired.

Stapes surgery in osteogenesis imperfecta: retrospective analysis of 34 operated ears.

Intraoperative findings of stapes surgery in 34 ears from 22 patients with genetically confirmed osteogenesis imperfecta (OI) are reported, as well as the audiometric results after the longest postoperative follow-up published to date. Twenty-nine out of 34 ears underwent primary stapes surgery and 5 ears revision surgery. Postoperative audiometric follow-up ranged from 6 months to 37 years. Stapes footplates were fixed in all ears. Additionally, footplates were thickened or fragile, stapes crura atrophic or fractured, and middle ear mucosae thickened or hypervascularized. Short-term postoperative audiometry revealed improved hearing and reduced air-bone gaps in 28/29 primary operated ears and in all revision cases. In the 22 ears with long-term postoperative follow-up (mean duration: 16 years), hearing gain was still significant at the latest audiometric evaluation. Independently of the patients being diagnosed with OI type I or IV and independently of the underlying OI genotype, beneficial results are obtained in the majority of OI patients undergoing primary or revision stapes surgery for reduction of conductive hearing loss components caused by stapes footplate fixation. Despite the progressive course of the concomitant sensorineural component, hearing gain remains beneficial over several decades.

Association between bone mineral density and hearing loss in osteogenesis imperfecta.

OBJECTIVES/HYPOTHESIS: Osteogenesis imperfecta (OI) is a heritable connective tissue disorder, predominantly characterized by bone fragility. In half of the patients, progressive hearing loss develops, which is associated with abnormal bony changes involving the middle ear ossicles and stapes footplate. In the present study, we investigated whether the development of hearing loss in OI may be related to the overall aberrant bone quality. STUDY DESIGN: Observational study. METHODS: Following audiologic evaluation, 56 adult OI patients were classified as presenting normal hearing or conductive/mixed or pure sensorineural hearing loss. Areal bone mineral density (BMD) (aBMD) was measured using lumbar spine (LS) and whole body (WB) dual X-ray absorptiometry. By means of peripheral computed tomography, volumetric BMD (vBMD) and morphometric bone parameters were determined at distal and proximal radius, providing separate results for trabecular and cortical bone. The obtained bone parameters were compared between normal-hearing OI patients and those with either conductive/mixed or pure sensorineural hearing loss. RESULTS: Z scores demonstrated decreased LS aBMD, WB aBMD, and trabecular vBMD in OI adults compared to the healthy population. Patients with conductive/mixed hearing loss had lower trabecular vBMD compared to those with normal hearing or pure sensorineural loss at both whole-group and between-relatives comparisons. CONCLUSIONS: It is hypothesized that OI patients with lower BMD might be more susceptible to accumulating microfractures, which may interfere with the bone remodeling inhibition pathways in the temporal bone and, therefore, contribute to stapes footplate fixation and a conductive hearing loss component.

Audiologic phenotype of osteogenesis imperfecta: use in clinical differentiation.

OBJECTIVES: To describe the audiologic phenotype in osteogenesis imperfecta (OI). STUDY DESIGN: Observational study. SETTING: Tertiary referral center. PATIENTS: One hundred eighty-two patients with genetically confirmed OI, aged 3 to 89 years. INTERVENTION: Diagnostic hearing evaluation through otoadmittance and acoustic stapedius reflex measurements, pure tone, and speech audiometry. MAIN OUTCOME MEASURE(S): Prevalence, type, severity, symmetry, and audiometric configuration of the hearing loss in OI. Progression of hearing thresholds was determined by constructing age-related typical audiograms. RESULTS: Approximately 52.2% of all OI patients demonstrated hearing loss unilaterally (7.7%) or bilaterally (44.5%). Pure conductive, mixed, and pure sensorineural hearing losses were observed in 8.5%, 37.8%, and 11.6% of OI ears, respectively. Multiple linear regression revealed that thresholds progressed by 0.5 dB/yr at 0.25 kHz to 0.8 dB/yr at 0.8 kHz in the ears with conductive or mixed hearing loss. Pure sensorineural hearing loss progressed by less than 0.1 dB/yr at 0.25 kHz to 1.2 dB/yr at 8.0 kHz. Audiometric configuration was predominantly flat (70.5%) in the ears with conductive/mixed loss and sloping (50.0%) in those with pure sensorineural loss. CONCLUSION: Patients with OI are at risk for hearing loss. The hearing loss in OI may initiate at a young age and is progressive. However, the rate of progression, as well as the hearing loss severity, onset, and configuration depend on the type of hearing loss, which may be conductive/mixed or pure sensorineural. For both types, age-related threshold audiograms are constructed and may help the clinician to estimate the course of the hearing loss in patients with OI. In addition, they may be valuable to distinguish between hearing loss associated with OI and other similar forms of hearing loss, such as in otosclerosis.

Osteogenesis Imperfecta: the audiological phenotype lacks correlation with the genotype.

BACKGROUND: Osteogenesis Imperfecta (OI) is a heritable connective tissue disorder mainly caused by mutations in the genes COL1A1 and COL1A2 and is associated with hearing loss in approximately half of the cases. The hearing impairment usually starts between the second and fourth decade of life as a conductive hearing loss, frequently evolving to mixed hearing loss thereafter. A minority of patients develop pure sensorineural hearing loss. The interindividual variability in the audiological characteristics of the hearing loss is unexplained. METHODS: With the purpose of evaluating inter- and intrafamilial variability, hearing was thorougly examined in 184 OI patients (type I: 154; type III: 4; type IV: 26), aged 3-89 years, with a mutation in either COL1A1 or COL1A2 and originating from 89 different families. Due to the adult onset of hearing loss in OI, correlations between the presence and/or characteristics of the hearing loss and the underlying mutation were investigated in a subsample of 114 OI patients from 64 different families who were older than 40 years of age or had developed hearing loss before the age of 40. RESULTS: Hearing loss was diagnosed in 48.4% of the total sample of OI ears with increasing prevalence in the older age groups. The predominant type was a mixed hearing loss (27.5%). A minority presented a pure conductive (8.4%) or pure sensorineural (12.5%) loss. In the subsample of 114 OI subjects, no association was found between the nature of the mutation in COL1A1 or COL1A2 genes and the occurrence, type or severity of hearing loss. Relatives originating from the same family differed in audiological features, which may partially be attributed to their dissimilar age. CONCLUSIONS: Our study confirms that hearing loss in OI shows a strong intrafamilial variability. Additional modifications in other genes are assumed to be responsible for the expression of hearing loss in OI.

Audiometric, surgical, and genetic findings in 15 ears of patients with osteogenesis imperfecta.

OBJECTIVES/HYPOTHESIS: To provide data on the outcome of stapes surgery in patients with osteogenesis imperfecta (OI). The audiometric results of 15 ears (12 patients), in which a stapes operation was performed, are presented and compared with results from literature. STUDY DESIGN: Retrospective study. METHODS: In 12 patients with genetically confirmed OI, intraoperative findings and audiometric evaluations were recorded. RESULTS: In all patients the genetic mutation was located in the COL1A1 gene. Surgical findings in OI may be particular like mobile, atrophic stapes crura combined with a fixation of the stapes footplate, which may be thickened, and a hypervascularized or thickened middle-ear mucosa. Outcome for hearing in 13 primary surgered ears was good because at short-term follow-up the air-bone gap was reduced in all cases. These results were maintained in the long-term, with exception of one ear, in which progression of the sensorineural component occurred shortly after the operation. Although initial success was noted in two ears with revision surgery, in the long term this was only maintained in one of them. CONCLUSIONS: In general, stapes surgery is successful in resolving the conductive hearing loss in OI patients, even in the long term. Hearing loss in OI is mostly of the mixed type, and the sensorineural component is reported to be progressive. Stapedotomy, by improving the hearing level, may facilitate the rehabilitation with a hearing aid. Because the identified mutation could be located in the COL1A1 gene in all patients, conductive hearing loss in OI caused by stapes fixation is possibly linked to a mutation in this gene. Laryngoscope, 2009.

Otologic disease in turner syndrome.

OBJECTIVE: This study involved the assessment of the otologic and audiologic characteristics of a group of patients with Turner syndrome. STUDY DESIGN: Prospective study consisting of a questionnaire (77 of 123 responders) and an otologic and audiologic evaluation in patients with Turner syndrome (41 participants). SETTING: Tertiary academic medical setting. PATIENTS: Children, adolescents, and adults with Turner syndrome (median age, 24 yr). INTERVENTIONS: Otomicroscopy, audiometry, immittance measurements, and diagnostic imaging. RESULTS: Otologic disease is an important characteristic in Turner syndrome. Sixty-six percent of the patients studied via the questionnaire reported a history of chronic or recurrent middle ear disease. Analysis of audiometric data in 40 patients tested reveals an equal amount of normal ears (38.8%) and pure sensorineural ears (38.8%), each constituting approximately one-third of the patient population. Pure conductive losses represent only one-fifth (21.3%) of auditory abnormality encountered. CONCLUSIONS: Careful follow-up during early childhood of children with Turner syndrome is necessary to detect middle ear disease and prevent sequelae. However, long-term periodic review is mandatory even after resolution of middle ear disease to detect sensorineural hearing loss.

Risk factors for the development of otitis media.

Otitis media (OM) is the most frequently diagnosed disease in infants and young children. Large, prospective studies suggest an increase in incidence of this disease during the past 10 to 20 years, possibly reflecting a change in host and environmental risk factors for the development of OM. Good knowledge of host (intrinsic) and environmental (extrinsic) risk factors for the development of otitis media is important in identifying a child at risk for recurrent and persistent OM. This could result in primary and/or secondary prevention of OM and a decrease in complications and sequelae.

Cochlear implantation in a patient with superficial siderosis of the central nervous system.

OBJECTIVE: To perform an assessment of the viability of cochlear implantation in a patient with superficial siderosis of the brain. STUDY DESIGN: Case review. SETTING: Tertiary referral center. PATIENTS: Patient with superficial siderosis of the brain. INTERVENTION: Cochlear implantation. MAIN OUTCOME MEASURES: Electrically evoked auditory brainstem responses and fitting strategy for cochlear implant based on patient's subjective responses. RESULTS: After some time, C levels and T levels showed a pattern comparable with the evoked auditory brainstem responses. CONCLUSIONS: Bilateral profound hearing loss after superficial siderosis of the brain is no absolute contraindication for implantation. Furthermore, evoked auditory brainstem measurements can potentially guide the fitting process of the implant in difficult cases.