A cochlear implant can be helpful if you have serious hearing loss. This is a device that is surgically implanted into your cochlea, the spiral-shaped bone in your inner ear. A cochlear implant converts sounds into electrical impulses, which are interpreted by the brain. It aims to replace the function of the cochlea. However, the device is not suitable for everyone and there are potential complications. The successful use of a cochlear implant also requires a great deal of therapy and training.
What is a Cochlear Implant?
A cochlear implant is a small electronic instrument that activates the cochlear nerve with electricity (nerve for hearing).
The implant has external and internal parts. The outer part is behind the ear. Pick up sounds with a microphone. Then it processes the sound and transmits it to the internal part of the implant.The cochlea, which is part of the inner ear, is accessed by a thin wire and small electrodes.
The wire sends signals to the cochlear nerve, which sends sound information to the brain to produce an auditory sensation. Although the normal hearing is not restored, with proper therapy and practice, the improved listening experience can mean greater awareness of sounds in the environment, as well as better communication through easier lip reading and listening. A cochlear implant can help a person with hearing loss restore or improve the ability to hear and understand speech. A hearing aid is not the same as a cochlear implant. A hearing aid makes sounds louder, but may not significantly improve speech understanding. When a person has difficulty understanding speech, even with properly fitting hearing aids, a cochlear implant should be considered. The cochlear implant will significantly improve hearing in adults when the instrument is properly adjusted and the patient is undergoing outpatient therapy. Cochlear implants in infants and young children can help them listen and learn to speak
Who Uses a Cochlear Implant?
A cochlear implant is not right for everyone. The way a person is selected for cochlear implants is changing as an understanding of the brain's auditory pathways improves and technology changes. Cochlear implants are appropriate for both infants and adults. Children as young as 1 year are now candidates for this surgery. Although the criteria are slightly different for adults and children, they are based on similar guidelines:
- The person must be totally or almost completely deaf in both ears and hardly improve with hearing aids. Cochlear implants are not used for those who can hear well enough with hearing aids.
- The person needs to be highly motivated. After the cochlear implant is in place, they must learn to use the device correctly.
- The person must have reasonable expectations about what will happen after the surgery. The implant does not preserve or produce "natural" hearing in the user.
- Children must be enrolled in programs that help them to learn process sound.
- An otolaryngologist must examine a person to determine if they are a candidate for a cochlear implant (otolaryngologist). Those who wear hearing aids will also require various forms of hearing checks.
- This may include a CT scan or MRI of the brain, the middle and inner ear.
- A psychologist may need to evaluate people (especially children) to determine if they are good candidates.
Cochlear Implant Procedure
Primary care physicians generally refer patients to ear, nose, and throat physicians (ENT doctors or otolaryngologists) to evaluate them and see if they are candidates for cochlear implants.
Frequently performed tests are:
- Examination of the outer, middle, and inner ear for signs of infection or abnormalities.
- Various hearing tests, such as an audiogram, BERA,OAE,Impedence.
- A hearing aid can be used as a test to assess their potential benefit.
- Exams to evaluate the structures of the middle and inner ear.
- CT scan (computed tomography). This helps the doctor see if the cochlea is in a normal shape. This scan is especially important if the patient has a history of meningitis because it helps to see if there is new bone growth in the cochlea that could interfere with implant insertion. This scan will also help assess which ear needs to be inserted.
- Magnetic resonance imaging (MRI) scan to see Cochlear nerve thickness and yo rule out any pathology in brain.
- Psychological evaluation to determine if the patient is capable of coping with the implant.
- Physical exam to prepare for general anesthesia.
The doctor or other hospital staff can:
- Insert some intravenous (IV) lines
- Shave or clean the scalp around the implant site
- Attach cables, monitors, and patches to the patient's skin to monitor vital signs.
- Place a mask on the patient's face to provide oxygen and anesthetic gas.
- Administer intravenous medications and mask to cause drowsiness and general anesthesia.
- Surgery is done under microscope. For one ear it takes about 2 hours and for both sides around 4 hours.
- Wake the patient in the operating room and take him to a recovery room until all anesthesia wears off.
Immediately after waking up, a patient may feel:
- Pressure or discomfort on the implanted ear
- Sore throat for a time from the breathing tube used during general anesthesia
- Keep the bandages on for a while
- Staining the bandages with some blood or liquid
- Go home about a day after surgery
- Get instructions on stitches care, head washing, showering, and general care and diet
- Make an appointment in about a week to have the stitches removed and the implant site examined
- Have the implant "turn on" (activate) approximately 3-6 weeks later
Complications of Cochlear Implant
While cochlear implant surgery is extremely secure, any procedure carries risks. Bleeding, infection are side effects of anesthesia. Other possible complications include:
- Facial Nerve damage
- Dizziness or balance problems.
- Hearing loss
- Ringing in your ears (tinnitus)
- Fluid leaks around the brain.
- Meningitis, an infection of the membranes that surround the brain. It's an uncommon but severe side effect.
If hearing aids cannot improve your hearing or speech, you may be a good candidate for a cochlear implant. Sound is converted into electrical impulses by this unit, which is surgically inserted in your cochlea and processed by your brain. An audiologist will use hearing exams and imaging tests to help determine if it is right for you, as well as your level of hearing loss. After surgery, it is important to commit to audiological rehabilitation. This is essential to improve your outlook and use the Cochlear Implant successfully.