Of the first 100 patients implanted on the Midland Cochlear Implant Programme the commonest aetiologies of deafness were idiopathic 31 per cent, meningitis 28 per cent and cochlear otosclerosis 16 per cent.The major complication rate was three per cent. The most severe was one individual who post-operatively developed a cerebral infarct and subsequently died. The minor complication rate was 39 per cent, all of which successfully resolved, and included 11 cases of wound infection, nine cases of vertigo, three transient facial palsies and two post-operative bleeds.Older patients and men were most likely to have a post-operative medical complication. Women were more likely to have an abnormal electrode insertion. Meningitis and otosclerosis were the most complicated aetiologies in terms of cochlear ossification and electrode insertion. A non-patient cochlea was associated with fewer active electrodes. In six cases which had been reported pre-operatively as showing patent cochleas, some form of obstructional ossification was encountered. Patients functioning with greater than 15 active electrodes performed better on auditory tests than patients with fewer than 15 active electrodes.

We present the outcome of implantation in the first 100 adult patients treated under the Midland Cochlear Implant Programme. All patients were post-lingually deaf with profound or total hearing loss. Performance was tested in lip-reading, implant only and combined lip-reading and implant modes using BKB sentences, connected discourse tracking (CDT) and environmental sound recognition. Assessments were made at nine and 18 months post-implant.The dominant aetiologies were idiopathic and meningitis. Meningitis was associated with the greatest numbers of ossified cochleas. Forty-three per cent of cases of partial ossification were identified only at surgery. Four per cent of patients became non-users of their devices, however the majority used their implants for more than 12 hours each day. The mean scores at nine months post-implant, in the implant only mode, were for environmental sound recognition 56.7 per cent, for BKB sentences 46.6 per cent (80 per cent of patients scored above 0 per cent) and for CDT 31.2 words per minute (w.p.m.) (62 per cent scored above zero per cent). In the combined lip reading and implant mode the mean scores, at nine months, were for BKB sentences 81.5 per cent and for CDT 65.8 w.p.m. All results were sustained at 18 months.Patients reported that implantation significantly reduced their hearing handicap. Pre-operative measures of depression were also significantly reduced at nine months post-implant. Results were sustained at 18 months.Post-operative audiological outcomes in the electrical stimulation only mode correlated significantly with length of profound deafness. Results suggest that performance outcome is also related to the number of active electrodes.

The relationship between tinnitus and cochlear implantation is an important issue that needs to be established because it may affect implant use. In this study 99 patients over 15 years of age completed pre-and post-cochlear implantation questionnaires, and underwent performance testing. The findings show that after implantation, there was marked suppression of tinnitus in both implanted and contralateral ears whilst the implant was off, and this was further enhanced when the implant was switched on. These effects are probably a combination of local and central factors. Presence of tinnitus, before or after implantation, had no detrimental effects on performance.In conclusion, providing all other factors permit, this study recommends implanting the ear with the worst tinnitus.

At switch-on (first post-operative stimulation of the implant) and during subsequent reprogramming, electrodes can, in some patients, be found to be non-functional or to be performing sub-optimally for a number of reasons. This paper examines the reasons for the poor performance of these electrodes by means of a retrospective analysis of 100 patient records. All of these patients received the Nucleus multichannel device.The most common reason for an electrode to require de-activation was found to be facial nerve stimulation, with poor sound quality and pain also being very common. Other reasons included absence of auditory stimulation, vibration, reduced dynamic range, throat sensations, absence of loudness growth or dizziness. The occurrence of these reasons along the electrode array was examined, more basal electrodes being found to be non-functional as a result of having a small dynamic range or poor sound quality. Pain and vibration were found to occur throughout the array and the more apical electrodes were found to be non-functional as a result of facial nerve stimulation. It is suggested that the electrodes at the basal end of the array are likely to be extra-cochlear or are at the site of the most cochlear damage, whereas the more apical electrodes lie in closer proximity to the facial nerve.

The objective of this study was to determine the findings on magnetic resonance imaging (MRI) in patients identified as having central vestibular abnormalities on electronystagmography (ENG) testing, to discuss the issue of 'gold standard' in the investigation of central oculo-vestibular system diseases and to present a model for understanding this area. A retrospective review of the case notes of patients (n = 23) found to have central ENG findings at vestibular assessment and for whom MRI scanning data was available was undertaken. Each patient underwent a full ENG evaluation, including gaze, ocular-motor and caloric testing, and MRI. Only seven of the patients with central ENG findings had abnormal MRI scans. Thus, the incidence of the identification of structural abnormality on MRI in patients with central ENG findings is low. These investigations are complementary in the investigation of balance disorder patients.