Auditory Brainstem Implant (ABI)

The ABI stimulates the brain stem itself; hence, it evades the damaged pathways entirely, providing some amount of hearing sensation.

For those with profound hearing loss involving Neurofibromatosis Type 2 (NF2), a genetically inherited disorder in which tumours form on the auditory nerves, ABIs are often lifesavers. It is a very technical procedure, involving an experienced neurosurgical team and an audiologist team to ascertain optimal placement and functionality of the implant. Also, in patients with Neurofibromatosis Type 2, oncologists may be referred due to the management of associated tumours and any additional treatments needed.

Marengo Asia Hospitals offers hope in life through advanced Auditory Brainstem Implants to individuals who are profoundly deaf. Our neurosurgery team uses advanced technology to ensure accurate and safe implant placement. By bringing together personalised treatment and compassionate care, we make sure to improve the hearing capability of the person and enhance their quality of life.

Who Needs an Auditory Brainstem Implant?

In general, the recommendation for an auditory brainstem implant applies to patients who:

• Have nonfunctional or missing auditory nerves typically due to NF2 or other congenital malformations.
• Are not able to take advantage of traditional cochlear implants due to various reasons like issues with their auditory pathway.
• Have had surgeries that damage the structures in their hearing system and block signal transmission to the brain.

Some of the conditions that may call for a procedure such as ABI include extreme levels of deafness, especially those that cannot be compensated by ordinary hearing aids or cochlear implants.

Is an Auditory Brainstem Implant the Same as a Cochlear Implant?

A cochlear implant is unlike an auditory brainstem implant, even though both help with hearing loss. A cochlear implant is implanted into the ears when loss of hearing has happened due to damage in the cochlea, but individuals still retain the auditory nerve. It bypasses the cochlea and directly stimulates the auditory nerve so that the sound signals can reach the brain. Surgery itself is relatively simple and most often it is performed on an outpatient basis.

An ABI is used for profound hearing loss that's caused by damage to the cochlea and/or auditory nerve. This device works directly on the brainstem pathways for hearing, making its placement a more complex surgery. The procedure requires the assistance of both an ear surgeon and neurosurgeon, usually when staying in a hospital as an inpatient.

What Tests or Diagnostic Procedures are Conducted Before an ABI Surgery?

Before an ABI surgery, several diagnostic tests are generally carried out to check the suitability of the patient to receive an implant. These tests ensure that the patient will benefit from the procedure and that the implantation will not harm but assist the patient. Key tests include:

1. MRI and CT Scans: The images of the structures are obtained using MRI and CT scans. These can provide detailed images of the brainstem and surrounding structures. MRI is particularly useful in identifying any tumours, structural abnormalities, or areas where the implant can be placed more precisely. These scans help guide the surgeon in formulating plans for placing the implant most effectively.

2. Audiometric Testing: Different comprehensive hearing tests are conducted, which determine the patient's current hearing capabilities to assess how much and to what degree the hearing is lost. These tests become a standard/baseline assessment of the patient's hearing function for the audiology team to contemplate post-surgery programming and rehabilitation.

3. Neurological Evaluation: A neurological examination is done to check the response of the brain to any type of auditory stimuli and assess the functionality of the auditory pathway and nerves. This evaluation provides the surgeon with a view of how the neural responses of the patient will be and can decide accordingly whether the patient is fit for the implant.

4. Speech and Language Assessment: A speech and language therapist will evaluate the patient's communication abilities, which would in turn point the way for implant programming and guide post-operative rehabilitation. This evaluation process will help to set realistic outcomes and inform the patient of what they can expect to happen with communication after the surgery.

What Happens During an Auditory Brainstem Implant Surgery?

In the process of implant surgery within the auditory brainstem, general anaesthesia is given, and the patient remains asleep throughout the procedure. The surgeon begins a stepwise method to reach into the brainstem for the placement of the implant. The process involves:

1. Incision and Access to Brainstem: It typically begins with an incision made behind the ear, which then exposes the brainstem area in which the auditory nucleus is located. The location of the incision chosen would then allow safe and effective access to that brain region so that the implant could be placed without disturbing other areas of the brain.

2. Placement of Electrode Array: The electrode array designed specifically is implanted on the surface of the cochlear nucleus, which is situated on the brain stem. This electrode array would be important for any implant to be operational, and it stimulates the cochlear nucleus directly and sends sound information into the brain.

3. Connection to Implant Device: The electrodes are then attached to an implantable device that will send signals from an external processor. This attachment allows the patient's auditory information to bypass damaged auditory nerves and directly engage the brain stem for the perception of sound to arise.

4. Closure: The surgeon closes the incision using sutures or staples once the implant has been placed and secured. This final step protects the implant site and aids healing.

The procedure may take several hours. The patient would then be kept within the hospital for observation to ensure that the implant is fine and there are no complications.

What Are the Benefits of an Auditory Brainstem Implant?

An ABI cannot restore normal hearing, but it can enhance a person's sound awareness and his or her ability to identify sounds. It can also help in lip-reading. These benefits will vary considerably from one individual to another.

Research findings indicate that children who experienced early life ABI, especially when deafness had occurred for only a limited period of time, have a much better vocabulary comprehension than adults suffering from NF2 who may have been deaf for a more extended period.

Further, the success of the procedure may depend on several other factors, including how much the patient participates in follow-up hearing therapy after the surgery, the size and location of any existing tumours, and the presence of other health issues.

You will need to discuss such factors with your doctor. You may then collaborate to decide whether an ABI would be the best option for you by weighing the risks and benefits. If you want to find an experienced surgeon for ABI procedure, you just need to visit our website. Once you are on our site, scroll a bit to discover the "Find a Doctor" section, where you’ll also find options to "Find a Hospital" and "Book an Appointment." Once this is done, click on "Find a Doctor," enter "Neurosurgery" as the specialty, and pick your desired location for treatment.

How to Prepare for ABI Surgery

Patients should prepare well for an auditory brainstem implant surgery to have a productive process and speedy recovery. Here is how to prepare.

1. Discuss Medications: Inform your doctor of all the medicines, vitamins, and supplements you are currently taking. Some medications that may be on prescription or over the counter need to be stopped before surgery. This is because these medications may interfere with anaesthesia and recovery as well.

2. Manage Medical Conditions: Inform your doctor of any past medical conditions, including high blood pressure and diabetes, or if you've recently had an infection. Both of these conditions must be kept under control for surgery and recovery to proceed well.

3. Quit Smoking and Avoid Alcohol: Tobacco and alcohol consumption must be stopped for two to three weeks before the procedure. Tobacco and alcohol hinder the action of anaesthesia and delay healing processes. Their absence before surgery would facilitate easier recovery during the postoperative period.

4. Fasting Before Surgery: You likely will be instructed to abstain from food and drinks on the night before surgery. This prevents anaesthesia complications during the procedure.

5. Prepare for Recovery: Plan appropriate postoperative care for support with your usual activities because you are likely to need help during the immediate recovery period. In addition, learn about the functions, benefits, and limitations of the ABI so you can set realistic expectations.

Recovery Tips After ABI Surgery

Following certain recovery tips after ABI surgery can ease the healing process. Some of the tips to follow include:

1. Limit Physical Activity: Begin with light activities, like walking, but avoid heavy lifting, strenuous exercise, or any movements that may put pressure on the incision site to allow proper healing.

2. Keep Incision Area Clean: Follow the wound care instructions from your doctor and keep the incision clean and infection-free. Always monitor the area for any signs of infections such as redness or unusual discharge.

3. Follow a Balanced Diet: A healthy diet rich in protein and fibre helps to recover faster. Include lean meats, beans, leafy greens, and whole grains to help heal and regain energy.

4. Avoid Loud Environments: The brain takes time to adapt to the new auditory input from the ABI, so avoid loud environments during the initial recovery phase. Gradual exposure to sound allows the brain to adjust more comfortably.

5. Avoid Smoking and Alcohol: Avoid smoking and drinking alcohol during the period of recovery as both seem to have a negative impact on healing and also might affect the implant's functionality.

6. Pain Management: You may be prescribed pain medication by your doctor to address any discomfort post-surgery. You might also use relaxation techniques, gentle movements, or cold compresses on areas that are of concern that have been recommended by your doctor to alleviate discomfort and manage tension.