Cochlear Implantation in Neurofibromatosis Type 2: Experience From the UK Neurofibromatosis Type 2 Service.

OBJECTIVE: To review the outcomes of cochlear implants (CI) in patients with neurofibromatosis type 2 (NF2) in a large cohort, and identify factors associated with poor hearing benefit. STUDY DESIGN: Fifteen-year retrospective national observational case series. SETTING: United Kingdom regional NF2 multidisciplinary teams. PATIENTS: Consecutive patients with NF2 receiving a CI. INTERVENTIONS: CI for hearing rehabilitation. MAIN OUTCOME MEASURES: 1) Audiometric performance at 9 to 12 months after implantation using City University of New York (CUNY) sentence recognition score, and Bamford- Kowal-Bench (BKB) word recognition score in quiet (BKBq), and in noise (BKBn). 2) CI use at most recent review. RESULTS: Sixty four consecutive patients, median age 43 years, were included. Nine to 12 months mean audiometric scores were: CUNY 60.9%, BKBq 45.8%, BKBn 41.6%. There was no difference in audiometric outcomes between VS treatment modalities. At most recent review (median 3.6 years from implantation), 84.9% with device in situ/available data were full or part-time users. Between 9 and 12 months and most recent review there was an interval reduction in mean audiometric scores: CUNY -12.9%, BKBq -3.3%, BKBn -4.9%. Larger tumor size and shorter duration of profound hearing loss were the only variables associated with poorer audiometric scores. Tumor growth at the time of surgery was the only variable associated with CI non-use. Individual patient response was highly variable. CONCLUSIONS: CI can provide significant and sustained auditory benefits to patients with NF2 independent of tumor treatment modality, with the majority of those implanted becoming at least part-time users. Larger datasets are required to reliably assess the role of independent variables.

Simultaneous bilateral cochlear implantation under local anaesthesia in a visually impaired adult with profound sensorineural deafness: A case report.

Objective: The National Institute of Clinical Excellence recommends that adult patients with severe to profound deafness are eligible for simultaneous bilateral cochlear implantation if they are blind or have other disabilities increasing their reliance on auditory stimuli. Cochlear implant (CI) surgery is routinely performed under general anaesthesia (GA), precluding patients who have higher risk associated with GA. Recent literature describes the safety and efficacy of performing unilateral CI surgery under local anaesthesia (LA). We report the first simultaneous bilateral CI under LA in the UK in an adult patient with profound sensorineural deafness and visual impairment.Case study: A 46-year-old gentleman, registered blind, presented with a 20-year history of bilateral progressive hearing loss. He was assessed as unfit for surgery under GA due to significant cardiac comorbidities. We performed simultaneous bilateral CI surgery under LA on the patient; he was discharged home the following day. Postoperative free field audiometry showed a significant improvement; speech discrimination using Bamford, Kowal and Bench sentences presented in quiet, increased from 0% pre-operatively to 100% four months post-operatively.Conclusion: Simultaneous bilateral CI surgery under LA is a safe and feasible procedure for eligible patients who may otherwise have been denied surgery due to their GA risk.

Outcomes of cochlear implantation in patients with neurofibromatosis type 2.

In neurofibromatosis type 2 (NF2) bilateral vestibular schwannomas (VS) or their treatment usually results in bilateral hearing loss. Cochlear implantation (CI) was traditionally not used in these patients due to concern that retrocochlear disease would render the implant ineffective. This paper describes the auditory outcomes of CI in 13 patients with NF2 and includes patients with untreated VS and patients undergoing VS removal with cochlear nerve preservation. The non-user rate was 7.7%. Of the active users, median CUNY score was 98%, median BKB score in quiet was 90% and median BKB score in noise was 68%. CI is a viable option in selected patients with NF2.

Auditory Brainstem Implantation in Neurofibromatosis Type 2: Experience From the Manchester Programme.

OBJECTIVE: To describe the experience of auditory brainstem implantation (ABI) in patients with Neurofibromatosis type 2 (NF2). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral centre. PATIENTS: Implanted with a Cochlear ABI22 or ABI24M between 1994 and 2009 because of NF2 disease. INTERVENTION(S): Rehabilitative. MAIN OUTCOME MEASURE(S): Surgical complication rate; audiological outcomes. RESULTS: There were 50 primary ABI insertions in 49 patients, including 16 inserted at the time of first side tumor removal as a sleeper, and two revision repositionings which failed to improve outcome. Postoperatively three patients had cerebrospinal fluid leaks which did not require reoperation, one patient had meningitis, and eleven patients suffered either temporary or permanent lower cranial nerve dysfunction. Twenty-nine patients became full time users; a further 12 patients became non-users. Three patients died while their device was inactive. Five patients retain serviceable contralateral hearing. Audiological open set testing of users showed means of: environmental sounds discrimination 51%; phoneme discrimination: with ABI alone 22%/lip reading (LR) 45%/ABI with LR 65%; sentence testing: with ABI alone 13%/LR 19%/ABI with LR 54%. CONCLUSIONS: The majority of patients with NF2 implanted with an ABI find the device a useful aid to communication in conjunction with LR and in recognizing common environmental sounds. A small proportion gain open set discrimination. Almost a third of patients may end up as non-users. There is probably an increased risk of postoperative lower cranial nerve dysfunction so careful preoperative assessment is advised.

Preliminary assessment of the feasibility of using AB words to assess candidacy in adults.

BACKGROUND: Adult cochlear implant (CI) candidacy is assessed in part by the use of speech perception measures. In the United Kingdom the current cut-off point to fall within the CI candidacy range is a score of less than 50% on the BKB sentences presented in quiet (presented at 70 dBSPL). GOAL: The specific goal of this article was to review the benefit of adding the AB word test to the assessment test battery for candidacy. RESULTS: The AB word test scores showed good sensitivity and specificity when calculated based on both word and phoneme scores. The word score equivalent for 50% correct on the BKB sentences was 18.5% and it was 34.5% when the phoneme score was calculated; these scores are in line with those used in centres in Wales (15% AB word score). CONCLUSION: The goal of the British Cochlear Implant Group (BCIG) service evaluation was to determine if the pre-implant assessment measures are appropriate and set at the correct level for determining candidacy, the future analyses will determine whether the speech perception cut-off point for candidacy should be adjusted and whether other more challenging measures should be used in the candidacy evaluation.

Cochlear implantation in early deafened, late implanted adults: Do they benefit?

OBJECTIVES: The aim of this study was to quantify the benefit gained from cochlear implantation in pre- or peri-lingually deafened patients who were implanted as adults Methods: This was a retrospective case-control study. Auditory (BKB/CUNY/3AFC/Environmental sounds), quality of life (GBI/HUI3) and cognitive (customized questionnaire) outcomes in 26 late implanted pre- or peri-lingually deafened adults were compared to those of 30 matched post-lingually deafened, traditional cochlear implant users. RESULTS: There was a statistically significant improvement in all scores in the study group following cochlear implantation. BKB scores for cases was 49.8% compared to 83.6% for controls (p=0.037). CUNY scores for cases was 61.7% compared to 90.3% for controls (p=0.022). The 3AFC and environmental sounds scores were also better in controls compared to cases but the difference was not statistically significant. Quality of life scores improved following implantation in cases and controls but the improvement was only statistically significant in the controls. There was a 7.7% non-user rate in the cases. There were no non-users in the control group. DISCUSSION: Early deafened,,late implanted patients can benefit audiologically from cochlear implantation and in this study the improvement in speech discrimination scores was greater than expected perhaps reflecting careful selection of patients. Nevertheless, audiological benefits are limited compared to traditional cochlear implant recipients with the implant acting as an aid to lip reading in most cases. CONCLUSION: With careful selection of candidates, cochlear implantation is beneficial in early deafened, late implanted patients.

A Retrospective Multicenter Study Comparing Speech Perception Outcomes for Bilateral Implantation and Bimodal Rehabilitation.

OBJECTIVES: To compare speech perception outcomes between bilateral implantation (cochlear implants [CIs]) and bimodal rehabilitation (one CI on one side plus one hearing aid [HA] on the other side) and to explore the clinical factors that may cause asymmetric performances in speech intelligibility between the two ears in case of bilateral implantation. DESIGN: Retrospective data from 2247 patients implanted since 2003 in 15 international centers were collected. Intelligibility scores, measured in quiet and in noise, were converted into percentile ranks to remove differences between centers. The influence of the listening mode among three independent groups, one CI alone (n = 1572), bimodal listening (CI/HA, n = 589), and bilateral CIs (CI/CI, n = 86), was compared in an analysis taking into account the influence of other factors such as duration of profound hearing loss, age, etiology, and duration of CI experience. No within-subject comparison (i.e., monitoring outcome modifications in CI/HA subjects becoming CI/CI) was possible from this dataset. Further analyses were conducted on the CI/CI subgroup to investigate a number of factors, such as implantation side, duration of hearing loss, amount of residual hearing, and use of HAs that may explain asymmetric performances of this subgroup. RESULTS: Intelligibility ranked scores in quiet and in noise were significantly greater with both CI/CI and CI/HA than with a CI-alone group, and improvement with CI/CI (+11% and +16% in quiet and in noise, respectively) was significantly better than with CI/HA (+6% and +9% in quiet and in noise, respectively). From the CI/HA group, only subjects with ranked preoperative aided speech scores >60% performed as well as CI/CI participants. Furthermore, CI/CI subjects displayed significantly lower preoperative aided speech scores on average compared with that displayed by CI/HA subjects. Routine clinical data available from the present database did not explain the asymmetrical results of bilateral implantation. CONCLUSIONS: This retrospective study, based on basic speech audiometry (no lateralization cues), indicates that, on average, a second CI is likely to provide slightly better postoperative speech outcome than an additional HA for people with very low preoperative performance. These results may be taken into consideration to refine surgical indications for CIs.

Subjective outcomes of auditory brainstem implantation.

AIM: To assess the long-term subjective benefits of auditory brainstem implants (ABIs) and investigate the extent to which ABI users perceive it to be a useful device. METHODS: Using the Manchester database, all 31 living patients registered as ABI users were identified and sent the ABI performance questionnaire. Data regarding daily duration of use, auditory fatigue, ability to differentiate between speech and environmental sounds, and subjective usefulness of the ABI in different listening conditions were collected. Patients were asked to rate the usefulness of the device in various settings on a scale of 1 (not useful) to 6 (very useful). The mean age at implantation was 33 years (13-73 yr), and the mean follow-up period was 6 years (1.5-15 yr). RESULTS: Between March 1994 and September 2009, 57 patients underwent ABI insertion. A total of 26 patients were not eligible for inclusion in the study (19 nonusers, 5 deceased, and 2 sleepers). Of the 31 eligible patients identified as ABI users, 23 returned the questionnaire, 1 was excluded as the questionnaire had been completed on his or her behalf, giving a net response rate of 71%. Mean duration of usage per day was 12.62 hours (range, 8-16 h). Seventy-one percent of the patients turned the processor off at one or more points during the day. Differentiation between speech and environment was achieved in 95%, and 70% were able to differentiate between gender and adult and pediatric voices. The ABI was perceived as most beneficial when dealing with a familiar voice in a quiet place, with a median usefulness score of 4, rising to 5 when used in conjunction with lip reading. The ABI was least useful when dealing with an unfamiliar voice in a loud place, with a mean score of 1, rising to 2 when used in conjunction with lip reading. In all environments, combining the ABI with lip reading served to increase usefulness ratings by at least 1 point. CONCLUSION: This study demonstrates that ABI users make use of their device for at least 12 hours per day on average and obtain considerable subjective benefit in speech discrimination when using the device with familiar speakers in a quiet environment. Benefit is less significant in noise and with an unfamiliar speaker. Lip reading enhances subjective benefit by at least 1 point, and lip reading training may have a role to play in maximizing subjective benefit.

Straight versus modiolar hugging electrodes: does one perform better than the other?

OBJECTIVE: To determine differences in speech perception outcomes for patients who received a CI422 and a Contour cochlear implant. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Thirty-two adults who underwent cochlear implantation. INTERVENTION: Cochlear implantation using a CI422 or Contour device. MAIN OUTCOME MEASURE: Bamford-Kowal-Bench (BKB) speech perception scores at 3 and 9 months after activation. RESULTS: The mean BKB scores at 3 months for the CI422 device were 86.0% in quiet and 55.1% in noise. This compares with 86.0% in quiet and 62.3% in noise for the Contour device. At 9 months, the mean BKB scores were 85.9% in quiet and 67.1% in noise for the CI422 and 90.1% in quiet and 77.6% in noise for the Contour device. There was no statistically significant difference (p > 0.05) between speech perception outcomes at 3 or 9 months. CONCLUSION: This study suggests that CI422 and Contour electrode both improve speech perception outcomes postoperatively, and there does not appear to be any significant difference in outcome between the two types of devices.

Audit of adult post-implant annual reviews and evaluation of patient-led review.

OBJECTIVES: Audits were carried out to assess the clinical effectiveness of historical annual review appointments and a new patient-led review system. METHODS: The written records of 100 patients who attended for an annual review appointment were retrospectively analysed. A further 50 patients who did not respond to the patient-led review offer letter were contacted to determine why they had not responded. The records of patients who subsequently attended for review were also analysed to evaluate their outcome. RESULTS: Ninety-one per cent of patients tested showed no change or an improvement in aided thresholds. Eighty-nine per cent of patients tested showed no change or an improvement in speech discrimination scores. Ninety-three per cent of patients tested showed no change in impedances. Fifty-two per cent of patients required a map check and 36% of patients needed some equipment changed. One patient out of 100 needed referral to Ear, Nose and Throat (ENT). Twenty per cent of the patients who did not respond to the review offer letter reported they had not received the letter. The remainder did not require an appointment or did not understand the system. DISCUSSION: The results indicate that the majority of patients' implant and functional performance remains stable over time. The process of patient-led review has been optimized, so patients fully understand the system and are not missed if they do not receive the letter. CONCLUSION: Patient-led review allows patients to take more responsibility, so they can participate more proactively in the maintenance of their implant and the centre is able to focus their resources on the patients who need it.

Progress of hearing loss in neurofibromatosis type 2: implications for future management.

The objective of this study was to describe changes in hearing over time in patients with neurofibromatosis type 2 (NF2) treated conservatively. A retrospective case review was conducted in a tertiary referral centre. Pure tone audiometry, speech discrimination scores, serviceable hearing (American Academy of Otolaryngology class A or B) and measurement of vestibular schwannoma (VS) size on magnetic resonance imaging were evaluated in 56 patients (89 ears) with NF2 with at least one conservatively managed VS. Over a mean follow-up period of 7 years (range 0.8-21 years) pure tone average thresholds increased gradually with a mean annual rate of 1.3 dB for the right ear (p = 0.0003) and 2 dB for the left ear (p = 0.0009). Speech discrimination scores dropped with an average annual rate of 1.3 and 0.34% in the right and left ear, respectively. Patients maintained serviceable hearing for an average of 7.6 years (range 2.7-19.3 years). The average annual VS growth was 0.4 mm without any correlation with hearing loss. There was a correlation between patients' age and pure tone threshold increase (p < 0.05 for both ears). In this selected population of patients with NF2, hearing threshold increases were very slow. In NF2 patients with indolently behaving tumours, serviceable hearing can be maintained for a significant length of time, making conservative management an attractive option.

Outcomes of cochlear reimplantation in adults.

OBJECTIVE: To determine the indications for, and auditory outcomes following, cochlear reimplantation in adults and investigate factors influencing outcome. STUDY DESIGN: Retrospective case series. SETTING: Cochlear implant program in a tertiary care hospital. PATIENTS: Thirty adults (32 ears) who have undergone cochlear reimplantation in the ipsilateral ear. INTERVENTION(S): Explantation and reimplantation of cochlear implant. MAIN OUTCOME MEASURE(S): Speech discrimination as measured using Bamford-Kowal Bench sentence testing in quiet (BKBq) and noisy (BKBn) environments. RESULTS: Best BKBq improved from 58.5% to 71.4% (p = 0.0242), and BKBn improved from 60.9% to 67.2% (p = 0.826) after reimplantation. Device failure was the most common indication for reimplantation. There was no significant difference in failure rate or outcome between implant manufacturers. The mean time to reimplantation was 4.7 years, and this was not related to auditory outcome. Otosclerosis and Ménière's disease may predispose to a worse auditory outcome after reimplantation. CONCLUSION: Cochlear reimplantation does not have a detrimental effect on auditory outcomes and in some cases results in improved speech perception.

Ipsilateral cochlear implantation after cochlear nerve preserving vestibular schwannoma surgery in patients with neurofibromatosis type 2.

OBJECTIVE: To investigate the outcomes from ipsilateral simultaneous or sequential cochlear implantation in patients with neurofibromatosis type 2 (NF2) after vestibular schwannoma removal with cochlear nerve preservation. STUDY DESIGN: Retrospective case series. SETTING: Single tertiary referral NF2 center. PATIENTS: Six patients with NF2. INTERVENTION: Removal of vestibular schwannoma (VS) with preservation of the cochlear nerve and cochlear implantation. Four patients had their surgery via a translabyrinthine approach. Two patients had a retrosigmoid approach. A cochlear implant was inserted at the same time as tumor removal in 4 cases and sequentially in 2 cases. MAIN OUTCOME MEASURES: Surgical and audiometric outcomes using Bamford-Kowal-Bench (BKB) and City of New York University (CUNY) sentence scores. RESULTS: The average age at implantation was 24 years (range, 15-36 yr). Follow-up ranged from 5 to 93 months, with an average of 38 months. All patients had useful hearing in the contralateral ear before surgery. One patient gained no benefit from cochlear implantation and proceeded to have an auditory brainstem implant. Of those that had functional cochlear nerves, the average BKB score in quiet was 64%, BKB score in noise was 42%, and CUNY score with lipreading was 97%. Results varied within the group, but all patients gained significant benefit and continue to use their CI at least intermittantly. CONCLUSION: The present series demonstrates that in selected cases, cochlear implantation can be successful after a translabyrinthine approach for VS removal and for restoring hearing after failed retrosigmoid hearing preservation surgery. All patients found the cochlear implant offered useful hearing even in the presence of contralateral hearing.

English consensus protocol evaluating candidacy for auditory brainstem and cochlear implantation in neurofibromatosis type 2.

OBJECTIVE: Hearing loss resulting from bilateral vestibular schwannomas (VSs) has a significant effect on the quality of life of patients with neurofibromatosis Type 2 (NF2). A national consensus protocol was produced in England as a guide for cochlear implantation (CI) and auditory brainstem implantation (ABI) in these patients. STUDY DESIGN: Consensus statement. SETTING: English NF2 Service. PARTICIPANTS: Clinicians from all 4 lead NF2 units in England. MAIN OUTCOME MEASURES: A protocol for the assessment, insertion and rehabilitation of CI and ABI in NF2 patients. RESULTS: Patients should undergo more detailed hearing assessment once their maximum aided speech discrimination score falls below 50% in the better hearing ear. Bamford-Kowal-Bench sentence testing scores below 50% should trigger assessment for auditory implantation, as recommended by the National Institute for Clinical Excellence guidelines on CI. Where this occurs in patients with bilateral stable VS or a unilateral stable VS where the contralateral cochlear nerve was lost at previous surgery, CI should be considered. Where VS surgery is planned, CI should be considered where cochlear nerve preservation is thought possible, otherwise an ABI should be considered. Intraoperative testing using electrically evoked auditory brainstem responses or cochlear nerve action potentials may be used to determine whether a CI or ABI is inserted. CONCLUSION: The NF2 centers in England agreed on this protocol. Multisite, prospective assessments of standardized protocols for auditory implantation in NF2 provide an essential model for evaluating candidacy and outcomes in this challenging patient population.

Cochlear implantation in patients deafened by ototoxic drugs.

OBJECTIVE: To investigate the outcome of cochlear implantation (CI) in patients deafened by ototoxic drugs and to compare this, with the outcome of CI in sudden sensorineural hearing loss (SSNHL) with a similar duration of deafness. METHODS: The Manchester Auditory Implant Centre database was reviewed to identify patients who were implanted to rehabilitate profound sensorineural hearing loss resulting from treatment with ototoxic agents and patients with SSNHL group. A retrospective case note review of selected patients was carried out. Primary outcome measure was post-implantation Bamford-Kowal-Bench (BKB) score in quiet in both the groups. Secondary outcome measure was any significant complications following implantation. RESULTS: We identified 14 patients in the ototoxic group, which were matched with 13 patients in the SSNHL group. The post-operative BKB score in the ototoxic group ranged from 33 to 100% (median score 91%). One patient had bilateral CI. One patient required explantation following an infection. The post-operative BKB score in the SSNHL group ranged from 16 to 100% (median score 88%). One patient in this group could not be tested using this method as they did not have open set speech discrimination. Two patients in this group had bilateral CI. The data were analysed using Mann-Whitney U test. There was no statistically significant difference in the BKB scores in the two groups of patients (P value -0.983). CONCLUSION: Patients with profound hearing loss secondary to ototoxic agents can be rehabilitated successfully with CI. The outcomes may be variable and may be dependent on the underlying pathology for which the ototoxic agents were prescribed.

Factors affecting auditory performance of postlinguistically deaf adults using cochlear implants: an update with 2251 patients.

OBJECTIVE: To update a 15-year-old study of 800 postlinguistically deaf adult patients showing how duration of severe to profound hearing loss, age at cochlear implantation (CI), age at onset of severe to profound hearing loss, etiology and CI experience affected CI outcome. STUDY DESIGN: Retrospective multicenter study. METHODS: Data from 2251 adult patients implanted since 2003 in 15 international centers were collected and speech scores in quiet were converted to percentile ranks to remove differences between centers. RESULTS: The negative effect of long duration of severe to profound hearing loss was less important in the new data than in 1996; the effects of age at CI and age at onset of severe to profound hearing loss were delayed until older ages; etiology had a smaller effect, and the effect of CI experience was greater with a steeper learning curve. Patients with longer durations of severe to profound hearing loss were less likely to improve with CI experience than patients with shorter duration of severe to profound hearing loss. CONCLUSIONS: The factors that were relevant in 1996 were still relevant in 2011, although their relative importance had changed. Relaxed patient selection criteria, improved clinical management of hearing loss, modifications of surgical practice, and improved devices may explain the differences.

Pre-, per- and postoperative factors affecting performance of postlinguistically deaf adults using cochlear implants: a new conceptual model over time.

OBJECTIVE: To test the influence of multiple factors on cochlear implant (CI) speech performance in quiet and in noise for postlinguistically deaf adults, and to design a model of predicted auditory performance with a CI as a function of the significant factors. STUDY DESIGN: Retrospective multi-centre study. METHODS: Data from 2251 patients implanted since 2003 in 15 international centres were collected. Speech scores in quiet and in noise were converted into percentile ranks to remove differences between centres. The influence of 15 pre-, per- and postoperative factors, such as the duration of moderate hearing loss (mHL), the surgical approach (cochleostomy or round window approach), the angle of insertion, the percentage of active electrodes, and the brand of device were tested. The usual factors, duration of profound HL (pHL), age, etiology, duration of CI experience, that are already known to have an influence, were included in the statistical analyses. RESULTS: The significant factors were: the pure tone average threshold of the better ear, the brand of device, the percentage of active electrodes, the use of hearing aids (HAs) during the period of pHL, and the duration of mHL. CONCLUSIONS: A new model was designed showing a decrease of performance that started during the period of mHL, and became faster during the period of pHL. The use of bilateral HAs slowed down the related central reorganization that is the likely cause of the decreased performance.

Cochlear implantation in patients profoundly deafened after head injury.

OBJECTIVE: There is very little information in the literature regarding outcomes of cochlear implantation in patients profoundly deafened after head injury. The aim of this study was to assess outcomes in this group of patients. STUDY DESIGN: Retrospective case review. SETTING: The Manchester Cochlear Implant Programme, University of Manchester. PATIENTS: Profoundly deafened patients after head injury who proceeded to cochlear implantation for auditory rehabilitation. MAIN OUTCOME MEASURES: Mean age and duration of deafness at implantation. Preimplantation and postimplantation speech perception outcomes were measured using Bench Kowel Bamford (BKB) sentences in quiet and noise, City University of New York sentences with lip reading and Arthur Boothroyd words scoring the percentage phonemes correct. RESULTS: Twenty patients received 23 cochlear implants. Mean age at implantation was 51 years (standard deviation, 12 yr). Mean duration of deafness at implantation was 12 years (range, 1-30 yr).Preimplantation BKB score in quiet of 0%. Mean postimplantation BKB score in quiet was 64% (range, 0%-100%) and in noise was 61% (range, 0%-97%). Three were nonusers, and 1 required reimplantation. There was a moderately negative correlation between outcome and age at implantation (r = -0.41, p < 0.05) and between outcome and duration of deafness (r = -0.52, p < 0.05). CONCLUSION: Cochlear implantation is an effective method for hearing rehabilitation in profoundly deafened patients after head injury. However, negative factors, such as significant injury to the central auditory pathway, basal turn obliteration, long duration of deafness, and nonauditory stimulation, should be considered in the preoperative assessment of these patients.