It is difficult to put into words the sadness and helplessness you feel when someone close to you, perhaps your own child, is born deaf, or loses their hearing completely due to some illness or accident. There are times when you think, "Is this how it will be for the rest of your life?" But with the advancement of technology, there are methods today that can bring light to even those with the most profound hearing loss. That is one of the special methods we are talking about today.
Simply put, what is ABI?
ABI is an abbreviation for `Auditory Brainstem Implant`. In Sinhala, it means `Auditory Brainstem Implant`. This is a special device that allows people with the most profound hearing loss, that is, the part of the inner ear that captures sound (the `cochlea` or ear shell) or the nerve that carries those sound signals to the brain (the auditory nerve) to sense sound , or is not present from birth.
Think of the nerve that carries sound from your ear to your brain as a bridge. If this bridge is broken, sound cannot cross and reach the brain. That's where the ABI device comes in. It bypasses the broken bridge (nerve) and sends signals directly to the part of the brain that controls hearing (the brainstem). This doesn't sound like normal hearing, but it does give you a great opportunity to reconnect with the world of sound.
What does this device look like? Does it have two parts?
Yes, this device has two main parts. One is worn outside the body, and the other is surgically implanted inside the body.
1. Processor: This is a part that is worn over the ear or on the side of the head, like a hearing aid. It uses a microphone to pick up the sounds around you. It then converts those sounds into electrical signals and sends them to the processor inside the body. This external part should be removed when you sleep at night.
2. Internal Implant: This is the part that is surgically implanted under the skin. It also has two other parts.
- Receiver-stimulator: This part, which is attached under the skin on the side of the head, receives signals from the outside.
- Electrode paddle: This small paddle at the end of the receiver is carefully placed over the cochlear nucleus complex in the brain. This directly stimulates the brain and creates the sensation of sound.
Who is this treatment most suitable for?
An ABI is not suitable for everyone with hearing loss. It is specifically designed for people with the most profound hearing loss who cannot benefit from any other hearing aid or cochlear implant.
This technology was first developed for people with a rare genetic condition called Neurofibromatosis 2 (NF2). In this disease, tumors (acoustic neuromas) develop along the auditory nerve. These tumors, even when surgically removed, can cause permanent damage to the auditory nerve. This can lead to complete loss of hearing in both ears.
In addition, an ABI can be beneficial for adults, children, and infants with the following conditions:
- For those born with a hearing loss (aplasia).
- For those whose auditory nerve has not developed properly (`hypoplasia`).
- For those who have lost hearing due to some deformity, incomplete development, or bony growth (cochlear ossification) of the inner part of the ear, the cochlea.
- For those who have suffered damage to the auditory nerve due to a serious skull injury (temporal bone fracture).
- For those with profound hearing loss that cannot be cured by any other treatment.
Although many people think it's a 'neural defect', the problem may actually be in the cochlea (the inner ear). So, before you decide that a cochlear implant is not right for you, be sure to talk to your doctor. He or she will be the one to test you and tell you exactly what is best for you.
What is the difference between an ABI and a Cochlear Implant?
Although both are hearing aids, the way they work and the situations they are used in are completely different. You will easily understand this by looking at this table.
| Comparison | Cochlear Implant | Auditory Brainstem Implant (ABI) |
|---|---|---|
| Who is it used for? | This is a commonly used method for people who have hearing loss due to a defect in the inner ear (cochlea), but whose auditory nerve is functioning well . | For those who have both the inner ear (cochlea) and/or the auditory nerve dysfunction . |
| How it works | It directly stimulates the auditory nerve , bypassing the defective part of the inner ear. | It directly stimulates the auditory brainstem , bypassing both the inner ear and the auditory nerve. |
| Nature of surgery | A relatively simple surgery. You can usually go home the same day. | A very complex brain surgery. Both an ear, nose, and throat specialist (`Neurotologist`) and a brain surgeon (`Neurosurgeon`) are often involved. You will have to stay in the hospital for several days. |
What happens before and after surgery?
Before surgery
Because this is a big decision, you and your condition will be carefully examined before surgery. This will include several tests:
- Hearing tests: Your hearing level is measured with and without hearing aids.
- Communication assessment: A speech therapist will examine your language development and communication style.
- Electrophysiological tests: Special tests are performed to determine exactly where and to what extent the hearing loss is.
- Scans: You may be asked to have a CT scan and an MRI scan to look at the inner parts of your ear, auditory nerve, and relevant areas of your brain.
- Medical history: Your doctor will ask about your complete medical history and details about your hearing loss.
After surgery
You will need to stay in the hospital for two to four days after the surgery. If this is done at the same time as removing an `NF2` tumor, the hospital stay may be longer.
But remember, the device doesn't work immediately after surgery. The medical team will activate the device about 4 to 6 weeks after surgery, when the wounds have healed well. After that, you'll need to go in for monthly visits for the first year to adjust the settings (programming) of the device to suit you.
How are the results? Are there any risks?
Results and benefits
The first thing to say is that an ABI will never restore normal hearing. However, the benefits it offers are significant:
- Awareness of sounds: You begin to notice sounds in your environment (like a dog barking, a phone ringing, a car approaching).
- Sound discrimination: Being able to distinguish and recognize things like a child's voice and an adult's voice.
- Lip-reading becomes easier: When you look at someone's lips along with the sound when they are speaking, your ability to understand what they are saying is greatly increased.
The results vary greatly from person to person. Children who receive an ABI at a young age (before their hearing loss has been long-term) have been shown to have a better ability to understand words than adults.
Risks and complications
Because this is a very complex brain surgery, the risks common to any brain surgery are also present. When performed by an experienced medical team, the likelihood of complications is very low. Some of the possible complications are:
- Leakage of the fluid surrounding the brain (`Cerebrospinal fluid`).
- Device malfunction or implanted electrode movement.
- Wound infection.
- Infections such as meningitis.
- Damage to a facial nerve (`Facial nerve palsy`).
- Discomfort due to stimulation of other parts unrelated to hearing.
Your medical team will discuss all of this with you in detail before surgery.
Take-Home Message
- An auditory brainstem implant (ABI) is a specialized device used for profound hearing loss caused by dysfunction of the auditory nerve or inner ear (cochlea).
- This is different from a cochlear implant. An ABI directly stimulates the auditory brainstem.
- Although this does not provide normal hearing, it greatly helps with sound awareness, sound recognition, and communication.
- This is a very complex surgery, and it is essential to make a decision after carefully discussing the benefits and risks associated with it with your doctor.
- Results can vary greatly from person to person, but with proper rehabilitation and follow-up, quality of life can be significantly improved.
💬 අදහස් (0)
තවමත් කිසිදු අදහසක් පළ කර නොමැත. ඔබේ අදහස පළමු වරට මෙහි එක් කරන්න.
ඔබේ අදහස එක් කරන්න