Cortical plasticity in the first year after cochlear implantation.

This study aimed to investigate changes in auditory and visual cortical activity over the first year following cochlear implantation using (18)F-fluorodeoxyglucose positron emission tomography. Subjects underwent scanning prior to the initial implant activation (control), after one to two months of implant use (early activation) and after one year of implant use (late activation). All subjects had activation of the auditory cortices. Group analysis using Statistical Parametric Mapping package SPM99 showed these became more focused over the first year of implant use. There was no evidence of left hemispheric dominance at any stage post implantation.Visual cortical activations were highly variable between patients and did not increase significantly between early and late activations. Taken together, our results lead us to suggest that the neural processes that occur during the first year of auditory rehabilitation following cochlear implantation vary between individuals to a greater extent than previously reported.

Nasal fracture reduction: local versus general anaesthesia.

OBJECTIVE: To investigate the outcomes from nasal fracture reduction performed under local anaesthesia (LA) and general anaesthesia (GA). METHOD: A randomised multi-centred prospective trial and cohort analysis. Patients were randomised into two groups, 74 (53%) underwent closed reduction under LA, 65 (47%) patients underwent closed reduction under GA. MAIN OUTCOME MEASURES: Pain scores and patient toleration of local or general nasal manipulation was noted. RESULTS: The pain score ranged from 0 (no pain) to 10 (unbearable pain). The mean pain score in the LA group was 3, compared to 2 in the GA group. LA manipulation was tolerated equally well as GA manipulation by 85% of the patients in each group. The number of patients requiring a septorhinoplasty was compared between LA 19/74 (26%), and GA 21/65 (32%). This failed to demonstrate a significant difference with a p value of 0.50. The absolute risk difference was 5% with a 95% confidence interval of (20% to -10%). CONCLUSION: This trial clearly shows LA to be as effective as GA in the first line management of nasal fractures. The degree of septal displacement and presence of nasal tip deviation were associated with persistent nasal deformity following nasal fracture reduction.

Predictors of audiological outcome following cochlear implantation in adults.

The objective of this study was to examine variables that may predict open set speech discrimination following cochlear implantation. It consisted of a retrospective case review conducted in a tertiary referral centre with a cochlear implant programme. The patients were 117 postlingually deafened adult cochlear implant recipients. The main outcome measures were Bench, Kowal, Bamford (BKB) sentence scores recorded nine months following implant activation. The variables studied were age at the time of surgery, sex, duration of hearing loss, aetiology of hearing loss, residual hearing, implant type, speech processor strategy, number of active electrodes inserted. Variables found to have a significant effect on BKB following univariate analysis were entered into a multivariate analysis to determine independent predictors. Multivariate ordinal regression analysis gave an odds ration of 1.09 for each additional year of deafness prior to implantation (confidence interval 1.06-1.13; p < 0.001). Duration of deafness prior to implantation is an independent predictor of implant outcome. It accounted for 9% of the variability. Other factors must influence implant performance.

Cerebrospinal fluid leak rate after the use of BioGlue in translabyrinthine vestibular schwannoma surgery: a prospective study.

OBJECTIVE: To determine the effectiveness of BioGlue surgical adhesive in dural and middle ear closure after translabyrinthine vestibular schwannoma surgery. STUDY DESIGN: A prospective study. SETTING: Tertiary neurotological referral center. PATIENTS: There were 24 patients in the BioGlue series. BioGlue was used in the same manner in all cases. All patients received similar postoperative care. INTERVENTIONS: We studied the use of BioGlue and its possible effect on further reducing our department's cerebrospinal fluid leak rate for translabyrinthine vestibular schwannoma surgery. MAIN OUTCOME MEASURES: Postoperative events were documented that enabled us to determine the overall cerebrospinal fluid leak rate (including incidence of various leak routes and morbidity). RESULTS: The overall cerebrospinal fluid leak rate was 62.5% (15 of 24). Rhinorrhoea was the commonest route (80%), followed by postaural wound leak (33.3%) and external auditory canal otorrhoea (33.3%). Forty percent of cases had more than one cerebrospinal fluid leak route; 73.3% of leak cases required lumbar drain insertion, 40% needed pressure bandaging, and 66.7% had to undergo formal surgical repair. Forty percent had recurrent leaks after the initial episode had completely ceased. The mean extra stay in hospital as a result of the cerebrospinal fluid leak was 13.3 days. CONCLUSION: Our preliminary prospective study of the use of BioGlue for dural and middle ear closure in translabyrinthine vestibular schwannoma surgery demonstrated poor results. The high cerebrospinal fluid leak rate associated with the unusual presentations and ensuing management difficulties in controlling these leaks lead us to recommend that BioGlue not be used in translabyrinthine vestibular schwannoma surgery. The manufacturers have noted our results and have considered adding our recommendation to the product data sheet.

The management of children with Down syndrome and profound hearing loss.

INTRODUCTION: Although, the association between Down syndrome (DS) and conductive hearing loss is well recognized, the fact that a small proportion of these children may have a severe to profound sensorineural hearing loss that could benefit from cochlear implantation (CI) is less well understood. The management of significant co-morbidities in children with DS can delay initial diagnosis of hearing impairment and assessment of suitability for CI can likewise be challenging, due to difficulties conditioning to behavioural hearing tests. METHODS: We performed a retrospective case note review of three children with DS referred to the Manchester Cochlear Implant Programme. RESULTS: Three illustrative cases are described including CI in a 4 years old. Using conventional outcome measurement instruments, the outcome could be considered to be suboptimal with a Categories of Auditory Performance score of 4 at 6 months post-op and at last follow up. In part, this is likely to reflect the delay in implantation, but the role of cognitive impairment must be considered. The cases described emphasize the importance of comprehensive radiological and audiological assessment in children with DS being considered for CI. CONCLUSION: The influence of cognitive impairment upon outcome of CI must be taken into account, but should not be considered a contra-indication to implantation in children with DS. Benefit that might be considered limited when quantified using existing general outcome measurement instruments, may have a significant impact upon psychosocial development and quality of life in children with significant cognitive impairment, or other additional needs.

Device nonuse among adult cochlear implant recipients.

OBJECTIVE: To examine the causes and prevalence of previous and current device nonuse among adults who have received cochlear implants. STUDY DESIGN: Retrospective case review. SETTING: Adult tertiary referral center for cochlear implantation. METHODS: Two hundred fourteen consecutively implanted adult patients. The length of implant use ranged from 1 month to 14 years. MAIN OUTCOME MEASURE: A period of 4 consecutive weeks of nonuse of cochlear implant, including both obligatory and elective nonuse. RESULTS: Twenty-nine adults (13.6% of implantees) were identified as having at some stage not used their device for a period of more than 4 consecutive weeks. The main reason was device failure (n = 11). Ten adults are current nonusers (4.7% of implantees). Reasons include surgical complication necessitating explantation (n = 3), comorbid illness (n = 3), elective nonuse (n = 2), audiologic complication (n = 1), and device failure (n = 1). CONCLUSION: The overall prevalence of device nonuse was noted to increase slowly with time. The role of psychologic factors in contributing to the decision of an individual to elect to opt out of device use remains unproven.

Epilepsy following middle-fossa extradural retraction: implications for driving.

New-onset epilepsy has several social and financial repercussions. Development of seizures after middle-fossa surgery is uncommon. We present two subjects who developed epilepsy following middle-fossa surgery, requiring treatment with anticonvulsants, and discuss the implications.

Bone-anchored hearing aids and unilateral sensorineural hearing loss: why do patients reject them?

OBJECTIVES: This study aimed to report the bone-anchored hearing aid uptake and the reasons for their rejection by unilateral sensorineural deafness patients. METHODS: A retrospective review of 90 consecutive unilateral sensorineural deafness patients referred to the Greater Manchester Bone-Anchored Hearing Aid Programme between September 2008 and August 2011 was performed. RESULTS: In all, 79 (87.8 per cent) were deemed audiologically suitable: 24 (30.3 per cent) eventually had a bone-anchored hearing aid implanted and 55 (69.6 per cent) patients declined. Of those who declined, 26 (47.3 per cent) cited perceived limited benefits, 18 (32.7 per cent) cited reservations regarding surgery, 13 (23.6 per cent) preferred a wireless contralateral routing of sound device and 12 (21.8 per cent) cited cosmetic reasons. In all, 32 (40.5 per cent) suitable patients eventually chose the wireless contralateral routing of sound device. CONCLUSION: The uptake rate was 30 per cent for audiologically suitable patients. Almost half of suitable patients did not perceive a sufficient benefit to proceed to device implantation and a significant proportion rejected it. It is therefore important that clinicians do not to rush to implant all unilateral sensorineural hearing loss patients with a bone-anchored hearing aid.

Bone conduction implants - a rapidly developing field.

BACKGROUND: Since their introduction in 1977, the technology and surgical techniques surrounding the use and application of bone-anchored hearing devices have developed considerably. OBJECTIVE: This article reviews current developments in the use of bone-anchored hearing devices, looking at the possible options for patients, complications encountered and future possibilities. CONCLUSION: Advances in surgical technique are described, with the move towards the use of linear incisions and no soft tissue reduction. Methods for preventing complications are analysed, with review of different abutments and the introduction of the active bone conduction implant.

Complications following adult cochlear implantation: experience in Manchester.

Cochlear implantation is regarded as a safe and effective treatment for the profoundly deaf. However, a proportion of patients suffer complications after implant surgery. This paper examines the complications encountered in 240 adult cochlear implant operations performed in Manchester between June 1988 and June 2002. Minor complications were defined as those that either settled spontaneously or with conservative management. The total number of minor complications was 61 (25.4 per cent of cases). Non-auditory stimulation, which resolved with implant reprogramming, was present in 53 cases (22.1 per cent). Major complications were defined as those requiring further surgery, explantation or causing a significant medical problem, and occurred in 15 patients (6.25 per cent). These included implant extrusion, implant sepsis, electrode migration, flap-related problems, and persistent non-auditory stimulation. Nine of the 15 patients suffering a major complication required explantation. There were no post-operative deaths, cases of meningitis, nor persistent facial palsies in the series.

Cochlear implants and positron emission tomography.

OBJECTIVE: This review aimed to summarise present knowledge surrounding cochlear implants and neuroplasticity using positron emission tomography. OVERVIEW: Cochlear implants are an established device for severe sensorineural hearing loss. However, the outcomes following a cochlear implant are variable and unpredictable. Furthermore, despite increasing numbers of implantations taking place, there are still uncertainties regarding how individuals learn to process speech using an implant. Functional neuroimaging studies using techniques such as positron emission tomography provide an insight into the cortical changes that take place in patients with cochlear implants. CONCLUSION: Only when the underlying mechanisms responsible for speech processing in implantees are understood can appropriate rehabilitation for those with poor speech perception be provided and outcomes improved.

Cochlear implantation in a child with CINCA syndrome who also has wide vestibular aqueducts.

Chronic infantile neurological cutaneous and articular (CINCA) syndrome is a severe auto-inflammatory disease, due to mutation of the CIAS1 gene. CINCA syndrome should be considered the most severe of a spectrum of three disorders all due to mutation of the CIAS1 gene. CINCA syndrome produces a triad of symptoms of neonatal onset: maculopapular urticarial rash, chronic meningitis, and chronic non-inflammatory arthropathy with recurrent fever. CINCA syndrome is also associated with sensory organ damage, especially progressive hearing loss and loss of vision. In this case report, we present the first case of cochlear implantation in a 13-year-old child with CINCA syndrome. Cochlear implantation was successful at rehabilitating the hearing loss with the child able to continue mainstream education, with her academic performance and speech discrimination both showing marked improvement. Anakinra (an interleukin 1 receptor antagonist) is now in widespread use to treat CINCA syndrome and is known to rapidly reverse the inflammatory features of CINCA syndrome. However, current evidence suggests that anakinra has limited effectiveness in reversing the sensorineural hearing loss seen in CINCA syndrome. We therefore propose that cochlear implantation is a viable treatment option in this rare yet severe auto-inflammatory disease, if the patient has failed to respond to anakinra. Owing to the unknown pathogenesis of the progressive hearing loss seen in CINCA syndrome and the limited effectiveness of anakinra in reversing the progressive hearing loss, we suggest that cochlear implantation is the modality of choice in rehabilitating severe-to-profound hearing loss not responsive to anakinra.

Bone-anchored hearing aids and chronic pain: a long-term complication and a cause for elective implant removal.

OBJECTIVES: To report a case series of elective removal of bone-anchored hearing aid implants, and reasons for removal. DESIGN: Retrospective review of a prospectively collected database. SETTING: Two tertiary referral centres in the Manchester area: Manchester Royal Infirmary and Salford Royal University Hospital. PARTICIPANTS: A series of 499 adults and children who had undergone a total of 602 implant insertions (1984-2008). MAIN OUTCOME MEASURES: Implant removal rates, and reasons. RESULTS: Twenty-seven of the 602 implants (4.5 per cent) required removal. Of these, 12 were due to pain (2.0 per cent), seven to persistent infection (1.2 per cent), three to failure of osseointegration (0.5 per cent), three to trauma (0.5 per cent) and two to other reasons (0.4 per cent). CONCLUSION: Chronic implant site pain represents the main reason why implants are removed electively, and affects 2 per cent of all implants. This complication has important medico-legal implications and should be discussed when obtaining informed consent for implantation.

Cortical activations in sequential bilateral cochlear implant users.

This study aimed to examine auditory and visual cortical activations in bilateral cochlear implant recipients using [(18)F]-FDG positron emission tomography. We aimed to compare the activations from use of the first implant alone, the second implant alone, and both implants together. When both implants were activated simultaneously, summation of cortical activity did not occur. The first and second implants demonstrated evidence of developing distinct neural networks. The first implants show stronger bilateral recruitment of the auditory areas than the second implants. Visual cortical activations occur in response to stimulation of the second but not the first implants. When both implants were activated together, there were no visual activations suggesting interaction between the first- and second-implant networks. These findings add to the existing knowledge of plasticity following cochlear implantation and demonstrate a variability of these processes that was previously unreported.

Can keratinocytes cause failure of osseointegration?

AIM: Bone-anchored hearing aids are well established, implanted devices. We present two patients who suffered mixed hearing loss and who underwent titanium implant placement in the temporal bone to enable attachment of bone-anchored hearing aids. Osseointegration is necessary for such implants to function. We report these two cases to highlight how such osseointegration may be disrupted. METHOD: Attached tissue from the explanted or removed titanium implants was examined by transmission electron microscopy and histopathological analysis. RESULTS: Attached tissue from both implants showed the presence of keratinocytes at the titanium implant and living bone interface. This was confirmed by histopathological analysis. In one case, there was frank keratinocyte proliferation, which had led to osseointegration failure; in the other case, such proliferation was present but not so advanced. CONCLUSION: These findings suggest that, in the cases reported, keratinocytes implanted between the titanium and the living bone, leading to disruption of osseointegration.

Auditory cortical activation and speech perception in cochlear implant users.

Cochlear implantation is generally accepted as a successful means of restoring auditory sensation to profoundly deaf individuals. Although most patients can expect a satisfactory outcome following implantation, some have poor speech perception outcomes. This investigation used [18F]-fluorodeoxyglucose positron emission tomography to measure cortical activity resulting from auditory stimulation in seven 'good' and four 'poor' cochlear implant recipients. Activations were significantly greater in both the primary and association cortices in the good compared with the poor implant users. We suggest that the ability to access the more specialised speech processing abilities of the auditory association cortices helps determine outcome following cochlear implantation.