With the goal of addressing lack of awareness and improving literacy surrounding cochlear implant use in adults, an international group of clinical experts in the fields of otology, audiology, and hearing science were brought together to form a Delphi panel from which a Consensus around cochlear implant candidacy was agreed and an International Consensus Paper created. In clinical research. The key aim of a Delphi consensus is to achieve a set of statements that reflect current clinical expert thinking in the field.This is the first time that experts from different countries and several continents have come together in order to create a document that reflects the status of cochlear implantation for adult recipients.
The scope of this consensus study was to develop consensus statements specifically related to the use of unilateral cochlear implants (CI) for the treatment of bilateral severe, profound, or moderate sloping to profound sudden sensorineural hearing loss (SNHL) in adults. However, further research to develop consensus statements on the use of bilateral CI in adults, unilateral and bilateral CI in children, combined electric-acoustic stimulation in children and adults and unilateral implantation for single-sided deafness and asymmetrical hearing loss in adults and children will also be important for optimizing hearing and Quality of Life (QoL) outcomes for patients.
Professor Gerard O’ Donoghue, steering committee member of the Consensus Delphi Process and Professor of Otology and Neurotology at the University of Nottingham stated
“We need everybody’s opinion, we need everybody’s help in mobilizing support, to drive forward an agenda that is favorable, for hearing impaired patients, especially those for whom cochlear implantation may be appropriate; and who at the present time are denied that intervention. Globally, we all have to unite to do this work, and to make sure that the interventions for hearing impairment are more readily available, for the millions of people who at the present time are denied it”.
The ultimate goal of the consensus statements is to raise awareness of cochlear implants, and improve clinical practice to provide the best possible hearing outcomes and quality of life in adults with SNHL who are eligible for a cochlear implant.The consensus statements set out recommendations on seven key areas as below:
Consensus Statement 1:
Awareness of cochlear implants among primary and hearing healthcare providers is inadequate, leading to under-identification of eligible candidates.
Clearer referral and candidacy pathways would help increase access to cochlear implants.
Best practice clinical pathway for diagnosis
Consensus Statement 2:
Detection of hearing loss in adults is important; pure tone audiometry screening methods are considered the most effective. The addition of a questionnaire or interview to the screening can improve the detection of sensorineural hearing loss.
Consensus Statement 3:
Preferred aided speech recognition tests for cochlear implant candidacy in adults include monosyllabic word tests and sentence tests, conducted in quiet and noise. Further standardisation of speech recognition tests is needed to facilitate comparison of outcomes across studies and countries.
Consensus Statement 4:
Age alone should not be a limiting factor to cochlear implant candidacy, as positive speech recognition and quality of life outcomes are experienced by older adults as well as younger adults.
Both curved (perimodiolar) and straight electrodes are clinically effective for cochlear implantation, with a low rate of complications.Consensus Statement 6:
When possible, hearing preservation surgery can be beneficial in individuals with substantial residual hearing.
Clinical effectiveness of cochlear implants
Cochlear implants significantly improve speech recognition in both quiet and moderate noise in adults with bilateral severe, profound, or moderate sloping to profound sensorineural hearing loss; these gains in speech recognition are likely to remain stable over time.
Both word and sentence recognition tests should be used to evaluate speech recognition performance following cochlear implantation.
Cochlear implants significantly improve overall and hearing-specific quality of life in adults with bilateral severe, profound, or moderate sloping to profound sensorineural hearing loss.
Adults who are eligible for cochlear implants should receive the implant as soon as possible to maximize post-implantation speech recognition.
Factors associated with post-implantation outcomes
Where appropriate, individuals should use hearing aids with their cochlear implant in order to achieve bilateral benefits and the best possible speech recognition and quality of life outcomes.
Many factors impact cochlear implant outcomes; further research is needed to understand the magnitude of the effects.
Long durations of unaided hearing loss do not rule out potential benefit of cochlear implants: individuals who receive an implant in an ear that was previously unaided for more than 15 years have been shown to experience improvements in speech recognition.
Adults who have undergone cochlear implantation should receive programming sessions, as needed, to optimize outcomes.
The relationship between hearing loss and depression, cognition, and dementia
Adults with hearing loss can be substantially affected by social isolation, loneliness, and depression; evidence suggests that treatment with cochlear implants can lead to improvement in these aspects of well-being and mental health. Longitudinal studies are needed to obtain further knowledge in this area.
There is an association between age-related hearing loss and cognitive/memory impairment.
Further research is required to confirm the nature of cognitive impairment in individuals with hearing loss, and its potential reversibility with treatment.
The use of cochlear implants may improve cognition in older adults with bilateral severe to profound sensorineural hearing loss.
Hearing loss is not a symptom of dementia; however, treatment of hearing loss may reduce the risk of dementia.
Cost implications of CIs
Unilateral cochlear implantation in adults is cost-effective when compared with no implant or no intervention at all and is associated with increased employment and income.