Thu, 24 Jan, 2019
Could cochlear implants improve your cognitive function?
Cochlear implants could be associated with improved speech perception and cognitive function in adults with profound hearing loss who are 65 years or older. Here is a comprehensive break-down of the associated options.
What is a cochlear implant?
It is a small electronic hearing device that provides a sense of sound to profoundly deaf patients by electronically stimulating the hearing nerve and bypassing damaged parts of the inner ear. It has both internal and external parts. The complex technology essentially emulates the function of an ear to receive, process and transmit sound waves.
The external part of a cochlear implant is placed just above the ear and involves a microphone and sound processor, which selects and arranges sound. While the transmitter converts the signals from the processor and converts them into electric impulses. The impulses are sent to the internal part of the implant, which is put in place surgically under general anaesthesia. This internal part involves a receiver and magnet under the skin behind the ear and a series of electrodes placed in the cochlear. The electrodes collect the impulses and send them to different regions of the auditory nerve.
A cochlear implant for someone who is considered deaf is a useful representation of sound in the environment and helps them to understand speech. It bypasses the damaged portions of the ear and directly stimulates the auditory nerve. Although it takes some time to learn or relearn, hearing by a cochlear implant allows the user to recognise warning signals, understand environmental noises and even have conversations.
Who needs them?
Cochlear implants are useful for children or adults who are deaf or severely hard-of-hearing. Many children who are deaf at birth receive cochlear implants from 12 months of age. However, adults who lose hearing later in life also frequently use the devices. These individuals are then able to associate the provided signals with sounds they remember, negating the need to learn lip-reading or sign language.
According to the Australian Communication Exchange, three in every four Australians over 70 are affected by hearing loss. This is largely due to the damage we expose our ears to on a day-to-day basis. Loud or excessive noise damages the hair cells in the cochlear, which unfortunately don’t regrow. As well as gradual hearing loss, many people may also have incidents that cause them to suddenly lose their hearing, meaning they will also require the assistance of these devices.
Use of a cochlear implant requires both a surgical procedure and significant therapy. Cochlear implantations are almost always safe, however, as with all surgical procedures there is always a small risk. Cochlear implants are quite costly, and the learning process is quite lengthy, however, the benefits are considered to be usually worthwhile.
Cochlear implant or hearing aid?
Hearing aids simply amplify sounds and can be easily fitted on the external part of the ear, requiring no surgical procedure. There are a variety of hearing aids available, which generally consist of a microphone, amplifier, miniature loudspeaker and battery. Hearing aids pick up and amplify surrounding sounds and help to make speech more intelligible. People with profound hearing loss or residual low frequency hearing will likely receive no benefit from hearing aids and will be considered for a cochlear implant.
Cochlear implants are an expensive piece of technology, possible adding up to around $40,000. Depending on your state Department of Health, funding is usually provided for a limited number of cochlear implants per year. Most Australian private health fund cover the costs of the implant and hospital expenses and holders of Gold Veteran Affairs cards are usually fully covered.
As well as financial costs, time costs must also be taken in to consideration. The assessment period usually takes three months, and then there is usually a few week’s wait for surgery. After surgery, the MAP (the programming for the cochlear implant) will need to be adjusted to the needs of its user.
Several studies have shown benefits. One that adult cochlear implant patients allow a more marked improvement physically, psychologically and socially than hearing aid patients. This means that cochlear implants can bring as much benefit to those with profound hearing loss as hearing aids bring to those with less severe hearing loss. Another found that cochlear implants vastly improve the quality of life of deaf patients over 50. Cochlear implants are found to be a cost-effective solution in this age group, due to their increase in health and emotional-related quality of life. Increases in speech perception scores showed a strong correlation with magnitude of health utility gains.
More recent research which was published online by JAMA Otolaryngology - Head and Neck Surgery. This research indicates that cochlear implantation is positively associated with improved cognitive function and speech perception in adults 65 years and older with profound hearing loss. Hearing impairment correlates strongly with cognitive decline, and in cases where hearing aids are not sufficient, cochlear implantation is seen to be highly beneficial for older patients.
This study also showed that cochlear implants not only improve speech perception – in both quiet and noise – however, they can also improve quality of life and show less incidence of depression. More than 80% of the 94 patients in the study with impaired cognitive function improved their brain function scores one year after implantation.
Who to see
If you have suddenly or gradually become profoundly hard-of-hearing, it is important to seek professional medical advice immediately. Help is available and seeking advice early could increase your quality of life.
Options are to either visit an otolaryngologist, a doctor specialising in the diagnosis of ear, nose and throat diseases; an audiologist, who has specialised training in identifying and measuring the type and degree of hearing loss and recommends option; or a hearing aid specialist, who conducts and evaluate basic tests and offers counselling. Because cochlear implantation is for more serious hearing loss, you will need to see a specialist and then be referred to receive surgical treatment.
Written by Greta Mayr. Republished with permission of Wyza.com.au.