Indications for cochlear implantation

This is an automatically translated article.

The article was consulted with Specialist Doctor II Nguyen Van Thai - Ear - Nose - Throat Doctor - Department of Otolaryngology and Head and Neck Surgery - Vinmec Danang International Hospital.
A cochlear implant is an electronic device that partially restores hearing. This is an option for people with severe hearing loss due to damage to the inner ear. The cochlear implant will transmit sound signals to the auditory nerve, and then to the brain, helping to restore hearing naturally.

1. What is a cochlear implant?

A cochlear implant is a small electronic device that electrically stimulates the cochlear nerve (nerve VIII), which transmits sound signals into the brain. The structure of the cochlear implant consists of an external part and an internal part:
The outer part is located behind the ear, receiving sounds in the surrounding environment with a microphone. The unit then processes the sound into an electrical signal and transmits it to the implant's internals. The inner part is placed under the skin behind the ear. A thin wire and tiny electrodes are guided to the cochlea, which is part of the inner ear. The wire transmits signals to the cochlear nerve, which sends sound information to the brain to produce the sensation of hearing. Although normal hearing is not restored, with appropriate therapy and practice, hearing is significantly improved. From there, the patient will have a perception of sound as well as learn to communicate better through easier listening and speaking. Thus, cochlear implantation is a radical treatment for hearing loss, helping deaf people restore or improve their ability to hear and understand speech. This device works differently from hearing aids. Hearing aids only make sounds louder, but they don't improve speech intelligibility much.
When a person has difficulty understanding speech, even with hearing aids, a cochlear implant should be considered. In adults, cochlear implants can significantly improve hearing. In babies and toddlers, this device can help children learn to listen and learn to speak, better form normal language ability.

2. When is a cochlear implant indicated?

Cochlear implants are performed to restore hearing in people with severe hearing loss who no longer receive effective help with hearing aids. At this point, a cochlear implant can significantly improve communication and quality of life:
Increase the ability to hear speech without visual cues such as lip reading Perceiving normal environmental sounds everyday routine Able to perceive target sounds in noisy environments Able to find where sounds come from Able to listen to TV shows, music and phone calls For cochlear implants After death, the patient should have one of the following indications:
Hearing loss so severe that it disrupts voice communication Not receiving benefit from hearing aids as determined by hearing tests specialized No medical condition or risk factors associated with cochlear implants Highly motivated to participate in hearing restoration after which Cochlear implant can be placed ear or both ears. Cochlear implant therapy is only beginning to be used in the treatment of severe bilateral hearing loss - especially for infants and children who are born deaf and mute.

3. How is the follow-up after cochlear implantation?

Cochlear implant surgery is generally safe. However, this intervention can still contain risks that need to be monitored as follows:
Permanent hearing loss in the other ear spontaneously. However, the mechanism of this phenomenon is still unclear. Encephalitis - meningoencephalitis. Therefore, adults and children are often vaccinated before cochlear implantation to reduce the risk of developing this disease after the procedure. Device error. Sometimes repeat surgery may be needed to repair or replace a faulty internal device. Device infection. Infection at the surgical site. Bleeding, hematoma at the surgical site. Facial nerve paralysis. Vestibular disorders, dizziness. Taste disorder. New or worsening tinnitus. Cerebrospinal fluid leak.

4. What is the process of cochlear implantation?

4.1 Preparation for surgery Cochlear implant surgery is performed under general anesthesia. Patients need to fast before surgery for a certain period of time. The patient should remember the history of anesthetic allergy and notify the doctor if any.
4.2 Indications for cochlear implantation Because this is an invasive intervention, the equipment cost is high, the patient needs to be evaluated and considered many times for the indication for cochlear implantation, to ensure this is the right choice. choose the most suitable. The doctor will evaluate and consider the following criteria:
Perform a specialist examination of the ear - nose - throat, evaluate the condition of the ear and mastoid bone. Hearing and voice tests Vestibular health tests Magnetic resonance imaging or cranial computed tomography to evaluate the condition of the cochlea and inner ear structures Mental health check-up in one certain cases to determine the patient's ability to learn to use cochlear implants actively. 4.3 Surgical process The surgeon will make an incision behind the ear to create a small hole in the skull bone at the mastoid region - where the internal device of the cochlear implant is to be placed. After that, the doctor will Make a small hole in the cochlea to insert the device's electrode inside. The skin incision will be sutured so that the internal device is under the skin.
4.4 After the procedure The patient may have a feeling of pressure or discomfort on the ear or in the ear on the side of the implant. Others may experience dizziness or nausea. However, most patients will recover or feel well enough to leave the hospital the day of surgery or the day after. Your doctor or audiologist will not activate the cochlear implant for about 2-6 weeks after surgery, to give the surgical site time to heal.
4.5 Device activation To activate the cochlear implant, the audiologist will take the following steps:
Adjust the sound processor to fit the patient Check the cochlear implant components to ensure Ensure effective coordination Identify the sounds the patient needs to hear Provide the patient, parent or guardian with information on proper care and use of the device Completing device settings so that the patient can hear to the best of his or her ability 4.6 Rehabilitation Hearing rehabilitation involves training the brain to be able to understand sounds heard through the cochlear implant. Everyday speech and environmental noise that is passively heard will sound different from what is actively heard and remembered.
The brain always needs time to realize what these sounds mean. This process takes place continuously, so the patient should wear the voice processor continuously when awake.

5. Effectiveness of treatment after cochlear implantation

The results of cochlear implant surgery are different for each person. Factors that can affect the outcome of a cochlear implant include: Age of hearing loss, time from hearing loss to cochlear implant surgery.
For children, the best results are usually achieved at an early age, just before they begin to have sound perception and start learning language. If so, children with congenital hearing loss after receiving a cochlear implant will have the opportunity to develop comprehensively, not inferior to normal children.
For adults, the best outcome is a short period of profound hearing loss before cochlear implantation. Cochlear implants are less effective for adults with little or no experience with sound.
In a nutshell, a cochlear implant is a small electronic device of choice when a hearing aid is insufficient to provide the clear sound needed to understand speech and spoken language. Early intervention is always key in this recovery. The chances of improvement decrease over time as hearing loss becomes severe. Therefore, for young children, deciding to have a cochlear implant as soon as indicated is a way to treat hearing loss and will help children develop normally.

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Articles source references: hopkinsmedicine.org, nidcd.nih.gov, mayoclinic.org