“An Introduction to Cochlear Implants” – update This note is intended to be read in conjunction with the 2002 edition of this publication. Preamble The manufacturers of Cochlear Implants operate in a worldwide competitive market. The good news is that this ensures the regular introduction to the market of improved devices, offering better performance and a wider range of features for users. The bad news is that it is very difficult to keep track of all these changes within this publication! At present the Association feels that the broad picture of implant technology provided by the 2002 edition is still valid, and does not consider it appropriate to commission a full revision of our booklet. However we suggest that readers also note the following supplementary material. Waiting Lists and Funding – page 14. This area has been impacted not only by changes in device technology and availability, but also by r epeated re-organisations within the NHS. The provision of implants is regarded by the NHS as being a “Specialised Service”, which means that the responsibility for funding implants has been transferred to a series of Regional Specialised Commissioning Groups, one for each of the standard Local Government Regions. It is hoped that this will lead to better informed decision making on implant cases than was the case when the budgets were held at PCT level. In 2006 the Department of Health asked the National Institute for Clinical Excellence [NICE] to conduct a Technology Appraisal on cochlear implants and to recommend commissioning rules for the NHS. This has resulted in probably the most detailed and impartial study anywhere in the world into the safety, effectiveness and economic benefits of implants. NICE’s decision, which is now mandatory for NHS commissioners, was published in January 2009 and can be seen in detail at: http://www.nice.org.uk/Guidance/TA166. In summary NICE say that “A cochlear implant in one ear is recommended as a possible option for everyone with severe to profound deafness if they do not get enough benefit from hearing aids after trying them for 3 months. Cochlear implants in both ears are recommended for the following groups with severe to profound deafness only if they do not get enough benefit from hearing aids after trying them for 3 months and the implants are placed during the same operation: [i] children, and [ii] adults who are blind or have other disabilities which mean that they depend upon hearing sounds for spatial awareness.” Bilateral Implantation – not covered in 2002 edition. Most people would subscribe to the concept that two ears are better than one, and in some other European countries Bilateral Implantation – i.e. the provision of independently functioning implants on both ears - is rapidly becoming the norm, especially in paediatric cases. Various studies in the UK and elsewhere have shown that many patients do derive some additional benefit from the second implant, especially in terms of [i] improved ability to discriminate between speech and background noise, and [ii] some ability to identify the direction from which the sound is coming. However when these benefits are assessed using the health service’s standard cost/benefit analysis methods they do not appear to offer such good value to the health service as does the provision of the first implant, and the merits of bilateral implantation are still a matter of debate within the NHS. The NICE study discussed above has now determined that they should be offered in all paediatric cases, and in a limited number of adult cases. NICE’s guidance is due for review in 2011, which will provide another opportunity to assess the case for bilateral implantation. Combined electro-acoustic stimulation - not covered in 2002 edition. Historically there has been a group of patients who have serious hearing problems, but have retained a small element of residual hearing, and have been unwilling to take the risk implicit in having this residual hearing destroyed by the provision of a conventional implant with a full length electrode array. Typically these patients have a small amount of low frequency hearing but little or no high frequency response. In recent years some trials have been undertaken – mainly using devices offered by Med-El – of a technique called Combined Electro-Acoustic Stimulation, which seeks to provide an optimal solution for this group of patients. The patient is fitted with an implant which has a shorter electrode array than usual, and thence doesn’t penetrate into the inner turn of the cochlear [see the ear diagram on page 7] which provides the low frequency hearing. The patient is then given a processor which combines an implant with a conventional acoustic hearing aid in a single package, and receives high frequency information through the implant and low frequency information through the conventional hearing aid. The initial results suggest that these systems could be of considerable value to patients with this specific form of hearing loss. Choosing an Implant – page 20 All of the manufacturers have introduced upgraded models over the last few years, often featuring higher stimulation rates and a wider range of speech processing strategies. Many models include a telemetry function which allows the surgeon to confirm that the implanted part is working satisfactorily before closing the wound. Several of them now include an inductive pick up coil [for use with suitable telephones, and with hearing loops in lecture theatres etc] as a standard facility. Several models are now approved for use with low-medium power MRI scans [see page 22], and some of them also allow for the temporary removal of the internal magnet under local anaesthetic to allow the user to undergo higher powered MRI scans. All the manufacturers now claim a degree of water resistance for their latest processor models. A detailed analysis of the latest model ranges would date very quickly, it would be best if readers consulted the manufacturers’ web sites and the extensive literature they can supply. Speech Coding Strategy – page 23 All of the manufacturers continue to research improved Speech Coding Strategies; in many cases this work is undertaken in conjunction with major universities. A key objective is to improve speech perception in the presence of background noise, which continues to be a major concern of most implant users. The search for better Speech Coding rules is aided by the steady improvements in the technology of the implant itself. This allows the patient to be offered a choice of coding rules, and to be offered the ability to have two or more different “maps” loaded into their processor. For example one map might be optimised to pick out speech in a relatively noisy background, and another might be optimised for listening to music. Address information – inside front cover, and pages 30/31 Please note the following revised contact information: National Association of Deafened People PO Box 50, AMERSHAM, Bucks, HP6 6XB Email: enquiries@nadp.org.uk Web www.nadp.org.uk Cochlear Europe Ltd 9 Weybridge Business Park Addlestone Road ADDLESTONE Surrey KT15 2UF Tel: 01932 871 500 Fax: 01932 871 526 The UK distributor for the Neurelec range is now Biosense Medical, see http://www.biosensemedical. com/index.htm. See also http://www.neurelec.com/ Back to News and Reports