Auditory Brainstem Implant NIH Clinical Trial @ USC-CHLA

In a clinical trial, backed by the National Institutes of Health (NIH), a multi-institutional team of hearing and communication experts led by the USC Keck School of Medicine, in association with Children’s Hospital Los Angeles, conceived and tested an auditory prosthesis for children born without a hearing nerve.

  • Cochlear implants have transformed hearing options for people born deaf or with severe hearing impairments, but they don’t work for everyone.
  • The new Auditory Brainstem Implant (ABI) allows for individuals born without a cochlear nerve to hear for the very first time.
  • Because the device produces a “pixilated” signal from the brainstem that is not sorted into the normal acoustic patterns detected by hearing people, children need training for the language centers of their brain to develop normally.

Hearing loss manifests in several forms, most of which can be partially restored through hearing aids and cochlear implants. However, for an individual born without a cochlear (hearing) nerve, there previously, was no alternative to deafness as the lack of a nerve made sound perception, no matter how loud, impossible outside of feeling vibration.

However, this is about to change as a new, groundbreaking, auditory brainstem implant (ABI) now bypasses the inner ear entirely and stimulates neurons directly at the human brainstem. The invasive ABI device, including an 8mm by 3mm 21-electrode array, must be surgically implanted in the skull, deep within the brain itself, on a very precise spot on the brainstem. A receiver fitted under the scalp is then linked to the electrode array, which lays on top of and directly stimulates a section of the brainstem called the cochlear nucleus.

Auditory Brainstem Implant

An auditory brainstem implant (ABI) is a surgically implanted electronic device that provides the sense of sound to a person who is profoundly deaf due to retrocochlear hearing impairment (usually a result of illness or injury that damaged the cochlea or auditory nerve and so precludes the use of a cochlear implant).

Auditory Brainstem Implant

An auditory brainstem implant (ABI) is a surgically implanted electronic device that provides the sense of sound to a person who is profoundly deaf due to retrocochlear hearing impairment (usually a result of illness or injury that damaged the cochlea or auditory nerve and so precludes the use of a cochlear implant).

Auditory Brainstem Implant

An auditory brainstem implant (ABI) is a surgically implanted electronic device that provides the sense of sound to a person who is profoundly deaf due to retrocochlear hearing impairment (usually a result of illness or injury that damaged the cochlea or auditory nerve and so precludes the use of a cochlear implant).

Auditory Brainstem Implant

An auditory brainstem implant (ABI) is a surgically implanted electronic device that provides the sense of sound to a person who is profoundly deaf due to retrocochlear hearing impairment (usually a result of illness or injury that damaged the cochlea or auditory nerve and so precludes the use of a cochlear implant).

While scientists believe that the ABI would be at its most effective with younger children, as their brains more easily absorb information as they develop, the technology has so far, only been approved by the F.D.A. for use with patients 12 years or older. This is particularly helpful to those afflicted with neurofibromatosis type II, an inherited disease that causes a non-malignant brain tumor on the hearing nerve thus rendering it ineffective; disabling information transmission from the inner ear to the brain. However, this type of treatment could prove far more beneficial if allowed on younger patients.

“Brain surgery isn’t to be undertaken lightly, especially in such young patients. But if the child were not implanted at all, the children are incredibly disadvantaged by their deafness”, Nan Bernstein Ratner, Ph.D, professor of Hearing and Speech Sciences at the University of Maryland, told a group of journalists on February 14th, 2015 during a seminar at the annual AAAS meeting (American Association for the Advancement of Science) taking place in San Jose, CA. “We have to remember that without these kinds of technologies, this is a child that faces an uphill battle in life.”

Overseas, surgeons have been doing ABI surgeries in children for over 10 years but there never was a formal safety or feasibility study done under regulatory oversight.

“Several of the young children who had ABIs implanted outside the United States have sought help at the USC-CHLA Center for Childhood Communication and we know that they now have the potential to understand speech. This really shows how powerful and flexible the brain is. By studying how the brain and the hearing system work together through this device, our team will set the gold standard for use of this technology.” added Robert V. Shannon, Ph.D, USC Keck School of Medicine Professor and investigator for the trial.

Auditory Brainstem Implant: Auguste Majkowski [July 2014]

A Los Angeles team of scientists and surgeons from Children’s Hospital Los Angeles (CHLA), Keck Medicine of the University of Southern California (USC), and Huntington Medical Research Institutes (HMRI) reported that sound registered in the brain of a deaf 3-year-old Canadian boy for the first time after doctors activated a hearing device that had been surgically implanted in his brainstem at CHLA. The surgery and clinical trial are part of an NIH-funded study (U01DC013031) devoted to testing the device’s safety and its use in young children.

Auditory Brainstem Implant: Auguste Majkowski [July 2014]

A Los Angeles team of scientists and surgeons from Children’s Hospital Los Angeles (CHLA), Keck Medicine of the University of Southern California (USC), and Huntington Medical Research Institutes (HMRI) reported that sound registered in the brain of a deaf 3-year-old Canadian boy for the first time after doctors activated a hearing device that had been surgically implanted in his brainstem at CHLA. The surgery and clinical trial are part of an NIH-funded study (U01DC013031) devoted to testing the device’s safety and its use in young children.
Auditory Brainstem Implant:
Auguste Majkowski [July 2014]

A Los Angeles team of scientists and surgeons from Children’s Hospital Los Angeles (CHLA), Keck Medicine of the University of Southern California (USC), and Huntington Medical Research Institutes (HMRI) reported that sound registered in the brain of a deaf 3-year-old Canadian boy for the first time after doctors activated a hearing device that had been surgically implanted in his brainstem at CHLA. The surgery and clinical trial are part of an NIH-funded study (U01DC013031) devoted to testing the device’s safety and its use in young children.
Auditory Brainstem Implant:
Auguste Majkowski [July 2014]

A Los Angeles team of scientists and surgeons from Children’s Hospital Los Angeles (CHLA), Keck Medicine of the University of Southern California (USC), and Huntington Medical Research Institutes (HMRI) reported that sound registered in the brain of a deaf 3-year-old Canadian boy for the first time after doctors activated a hearing device that had been surgically implanted in his brainstem at CHLA. The surgery and clinical trial are part of an NIH-funded study (U01DC013031) devoted to testing the device’s safety and its use in young children.

This new clinical trial based at USC-CHLA, a three-year NIH study launched in March 2014, is a first as it will allow for children younger than 12 to go through an auditory brainstem implant as they would otherwise not qualify for a cochlear transplant due to their anatomy (cochlear implants, placed in the ear to mimic the auditory wiring there, require a functioning cochlear nerve).

For the language centers of the brain to develop normally, children need major information input – studies have shown that those who hear fewer words per day are slower to develop vocabulary skills than kids who hear more.

“It’s a myth to assume that the device goes in and the kid starts to figure out how to interpret the sounds,” agreed Nan Bernstein Ratner. “It’s an awful lot of education and therapy that has to go along so that the child can reconcile the cues that they see on people’s faces with the noises that they’re hearing.”

Because brains of deaf children are unfamiliar with sound, it takes greater effort to develop the necessary comprehension skills so that they can make sense of their initial sonic encounter, a garbled mix of sounds.

“Initial activation of the ABI is analogous to a newborn entering the world and hearing for the first time, which means these children will need time to learn to interpret what they are sensing through the device as ‘sound,’” said USC Keck otolaryngology professor / study co-leader audiologist Laurie S. Eisenberg, Ph.D. She adds that with the device, the child still needs to undergo therapy and interaction with, as their brains have to learn to map out the sounds and decode them: “The incoming stimulus for a child with an ABI is completely scrambled, and as a result, children with ABI require intensive long-term therapy and very strong parental involvement.”

An ABI implant is also a way for researchers to study early brain development as it goes through sound recognition and speech construction, shedding light on how sound impacts neuron creation and underlining the incredible plasticity of the organ, “It’s like learning how to see x-rays or detect electrical fields — something you can’t even imagine because you can’t do it,” said Robert Shannon.

Auditory Brainstem Implant: Angela Lopez [November 2014]

Three-year-old Angela Lopez, who was born deaf due to the lack of working auditory nerves, can now hear the world thanks to a revolutionary auditory brain implant (ABI). Part of a National Institutes of Health-funded clinical trial (U01DC013031) in progress at USC-CHLA Center for Childhood Communication. The little girl went through an intricate surgery during which an ABI, an electronic device that delivers stimulation directly to the brainstem, was implanted into her brain. Mere months after the procedure, Angelica can already distinguish various sounds and is progressively finding her own voice.

Auditory Brainstem Implant: Angela Lopez [November 2014]

Three-year-old Angela Lopez, who was born deaf due to the lack of working auditory nerves, can now hear the world thanks to a revolutionary auditory brain implant (ABI). Part of a National Institutes of Health-funded clinical trial (U01DC013031) in progress at USC-CHLA Center for Childhood Communication. The little girl went through an intricate surgery during which an ABI, an electronic device that delivers stimulation directly to the brainstem, was implanted into her brain. Mere months after the procedure, Angelica can already distinguish various sounds and is progressively finding her own voice.
Auditory Brainstem Implant:
Angela Lopez [November 2014]

Three-year-old Angela Lopez, who was born deaf due to the lack of working auditory nerves, can now hear the world thanks to a revolutionary auditory brain implant (ABI). Part of a National Institutes of Health-funded clinical trial (U01DC013031) in progress at USC-CHLA Center for Childhood Communication. The little girl went through an intricate surgery during which an ABI, an electronic device that delivers stimulation directly to the brainstem, was implanted into her brain. Mere months after the procedure, Angelica can already distinguish various sounds and is progressively finding her own voice.
Auditory Brainstem Implant:
Angela Lopez [November 2014]

Three-year-old Angela Lopez, who was born deaf due to the lack of working auditory nerves, can now hear the world thanks to a revolutionary auditory brain implant (ABI). Part of a National Institutes of Health-funded clinical trial (U01DC013031) in progress at USC-CHLA Center for Childhood Communication. The little girl went through an intricate surgery during which an ABI, an electronic device that delivers stimulation directly to the brainstem, was implanted into her brain. Mere months after the procedure, Angelica can already distinguish various sounds and is progressively finding her own voice.

The NIH full clinical trial (U01DC013031), available to children age 2 to 5, will eventually include ten participants and, out of five children enrolled so far, four of them have had an ABI surgically implanted. As per Eric P. Wilkinson, M.D., House Clinic otolaryngologist and trial investigator (participant of the 2015 AAAS Annual Meeting press briefing), it is estimated that nearly 100 children in the U.S. each year might benefit from an ABI. The trial covers the costs of the device, procedure and subsequent testing granted that the child applying could not qualify for a cochlear implant or hearing aid implant.

In patients where ABIs work best, the device could provide a sound signal “that’s enough to follow a conversation and even to speak on the telephone,” concluded Shannon, an otolaryngology researcher at USC.

As an ABI implant represents a technically challenging procedure, House Clinic surgeon Marc S. Schwartz, M.D. clarifies “we have to provide parents with the information to determine whether it’s worthwhile to go through an operation like this.”

Eventually, the USC Keck-CHLA researchers hope to find out if not only the ABI transplant is effective, but if the surgery can be easily reproduced in larger numbers and in the safest manner in children.

Auditory Brainstem Implant in the Fight Against Childhood Deafness [2015-02-14 Discussion part of ‘Neuroscience of Hearing’ Series @ AAAS 2015 Annual Meeting]

Saturday, 14 February 2015: 3:00 PM-4:30 PM
Room 230C (San Jose Convention Center)

Once a major life-handicapping condition, childhood deafness can be overcome thanks to the innovation of the cochlear implant (CI), a sensory device that assists deaf children in developing listening skills and spoken language despite the fact that the signal conveyed to the brain is quite unlike speech. While the CI is a major breakthrough, many children cannot use a CI because they were born with a deficient or absent cochlear nerve. How can we enable hearing in the absence of necessary elements of the human auditory system? Multidisciplinary synergy across areas of neuroscience, rehabilitation, and education has enabled development of the auditory brainstem implant (ABI). Unlike older devices, an ABI is placed directly on the cochlear nucleus of the brainstem, bypassing the cochlea and auditory nerve. Auditory information is converted to electrical signals that travel from the brain stem to the auditory cortex. As with other surgical innovations such as the CI, intense collaboration among specialists in neuroimaging, neurosurgery, speech-language pathology, audiology, education, and psychology is required to enable this groundbreaking device to bridge the child’s experience with the hearing world and teach the child how to interpret the incoming flood of sensory information. Despite public perception, a device alone cannot cure deafness. Rather, multiple disciplines must join forces to combat this most devastating of communication impairments in preschool-aged children.

Born Without an Auditory Nerve: Auditory Brainstem Implant to the Rescue

Babies born deaf are typically referred for a cochlear implant (CI), an auditory prosthetic device that is surgically implanted in the inner ear. Many children with the CI learn to understand speech without visual cues, acquire spoken language, and are mainstreamed into regular classrooms. Despite the general success of the CI in children, a small proportion of this population is not eligible for the CI because of a deficient auditory nerve or other anatomical deformities. By necessity, such children become reliant on sign language as their primary means to communicate and are typically placed in special school programs for deaf children. Now, another type of implantable auditory device, the auditory brainstem implant (ABI), is undergoing FDA clinical trials to bring hearing to these children. The ABI is similar to the CI but bypasses the cochlea and is placed directly on the cochlear nucleus of the brainstem. The ABI delivers a more scrambled pattern of information to auditory cortex than does the CI, and this pattern is highly degraded and distorted compared to normal hearing. Yet there is emerging evidence that the plasticity of the developing auditory cortex is sufficient so that young deaf children can decipher this scrambled signal and learn to understand speech and language. The focus of this presentation is to discuss emerging communication outcomes in pediatric ABI recipients. Notably, the children enrolled in the pediatric ABI clinical trial are being assessed on the same battery of speech perception tests that is used in a national, multicenter study on pediatric cochlear implantation. Use of this battery allows us to compare auditory development between pediatric CI and ABI users. Data from our center and those from other investigators are showing that auditory development in well-selected children appears to follow a similar trajectory to that of children with CIs. These early data suggest that the child’s brain is able to unscramble the ABI signal in a way that enables the acquisition of spoken language.

When To Choose Auditory Brainstem Implantation Instead of Cochlear Implantation in Children

For any deaf child, earliest intervention is critical. But not all can benefit from a cochlear implant (CI). Even when physiological and anatomical deficits are identified, it is not easy to answer the controversial question of which children should receive a CI or auditory brainstem implant (ABI). We have initiated an exciting new study that will provide important information about when to implant a child with abnormal inner ears with one of these devices to profit from increased sound awareness at the earliest age possible.

How does one make these evaluations in such small patients who cannot communicate directly with us? Along with audiological testing, electrophysiological testing can give us insight as to what the child perceives. New advances in Magnetic Resonance Imaging (MRI) can help identify the potential absence of a cochlear nerve that would preclude benefit from cochlear implantation. However, imaging has not been entirely predictive of a child’s response to CI, and surprisingly, some patients with apparent absence of auditory nerves have had satisfactory responses to CI. Possible reasons for this will be discussed.

Severe inner ear abnormalities may preclude placement of CI or indicate such poor prognosis as to lead to an early decision to implant ABI. Additionally, while a CI is a less invasive procedure, if benefits are not seen quickly, patients may need to be speedily routed into the ABI pathway. In this presentation, examples will be discussed of cases where CI may be appropriate (open cochlea, present but possibly deficient nerve tissue) and where immediate ABI may be needed (significantly deformed or absent cochlea, completely absent nerve tissue).

Putting a Powerful Computer in a Small Patient: Challenges in Providing an ABI

The auditory brainstem implant (ABI) can be viewed simplistically as a digital sound processor made small enough to implant in the brain. Placing this new auditory sensory device in a very young child can be especially challenging, but is necessary to overcome the life handicap of profound hearing loss in the congenitally deaf child. We explain the multidisciplinary problem-solving required to enable ABI placement in the developing nervous system of the young deaf child.

Auditory Brainstem Implant in the Fight Against Childhood Deafness [2015-02-14 Discussion part of ‘Neuroscience of Hearing’ Series @ AAAS 2015 Annual Meeting]

Saturday, 14 February 2015: 3:00 PM-4:30 PM
Room 230C (San Jose Convention Center)

Once a major life-handicapping condition, childhood deafness can be overcome thanks to the innovation of the cochlear implant (CI), a sensory device that assists deaf children in developing listening skills and spoken language despite the fact that the signal conveyed to the brain is quite unlike speech. While the CI is a major breakthrough, many children cannot use a CI because they were born with a deficient or absent cochlear nerve. How can we enable hearing in the absence of necessary elements of the human auditory system? Multidisciplinary synergy across areas of neuroscience, rehabilitation, and education has enabled development of the auditory brainstem implant (ABI). Unlike older devices, an ABI is placed directly on the cochlear nucleus of the brainstem, bypassing the cochlea and auditory nerve. Auditory information is converted to electrical signals that travel from the brain stem to the auditory cortex. As with other surgical innovations such as the CI, intense collaboration among specialists in neuroimaging, neurosurgery, speech-language pathology, audiology, education, and psychology is required to enable this groundbreaking device to bridge the child’s experience with the hearing world and teach the child how to interpret the incoming flood of sensory information. Despite public perception, a device alone cannot cure deafness. Rather, multiple disciplines must join forces to combat this most devastating of communication impairments in preschool-aged children.

Born Without an Auditory Nerve: Auditory Brainstem Implant to the Rescue

Babies born deaf are typically referred for a cochlear implant (CI), an auditory prosthetic device that is surgically implanted in the inner ear. Many children with the CI learn to understand speech without visual cues, acquire spoken language, and are mainstreamed into regular classrooms. Despite the general success of the CI in children, a small proportion of this population is not eligible for the CI because of a deficient auditory nerve or other anatomical deformities. By necessity, such children become reliant on sign language as their primary means to communicate and are typically placed in special school programs for deaf children. Now, another type of implantable auditory device, the auditory brainstem implant (ABI), is undergoing FDA clinical trials to bring hearing to these children. The ABI is similar to the CI but bypasses the cochlea and is placed directly on the cochlear nucleus of the brainstem. The ABI delivers a more scrambled pattern of information to auditory cortex than does the CI, and this pattern is highly degraded and distorted compared to normal hearing. Yet there is emerging evidence that the plasticity of the developing auditory cortex is sufficient so that young deaf children can decipher this scrambled signal and learn to understand speech and language. The focus of this presentation is to discuss emerging communication outcomes in pediatric ABI recipients. Notably, the children enrolled in the pediatric ABI clinical trial are being assessed on the same battery of speech perception tests that is used in a national, multicenter study on pediatric cochlear implantation. Use of this battery allows us to compare auditory development between pediatric CI and ABI users. Data from our center and those from other investigators are showing that auditory development in well-selected children appears to follow a similar trajectory to that of children with CIs. These early data suggest that the child’s brain is able to unscramble the ABI signal in a way that enables the acquisition of spoken language.

When To Choose Auditory Brainstem Implantation Instead of Cochlear Implantation in Children

For any deaf child, earliest intervention is critical. But not all can benefit from a cochlear implant (CI). Even when physiological and anatomical deficits are identified, it is not easy to answer the controversial question of which children should receive a CI or auditory brainstem implant (ABI). We have initiated an exciting new study that will provide important information about when to implant a child with abnormal inner ears with one of these devices to profit from increased sound awareness at the earliest age possible.

How does one make these evaluations in such small patients who cannot communicate directly with us? Along with audiological testing, electrophysiological testing can give us insight as to what the child perceives. New advances in Magnetic Resonance Imaging (MRI) can help identify the potential absence of a cochlear nerve that would preclude benefit from cochlear implantation. However, imaging has not been entirely predictive of a child’s response to CI, and surprisingly, some patients with apparent absence of auditory nerves have had satisfactory responses to CI. Possible reasons for this will be discussed.

Severe inner ear abnormalities may preclude placement of CI or indicate such poor prognosis as to lead to an early decision to implant ABI. Additionally, while a CI is a less invasive procedure, if benefits are not seen quickly, patients may need to be speedily routed into the ABI pathway. In this presentation, examples will be discussed of cases where CI may be appropriate (open cochlea, present but possibly deficient nerve tissue) and where immediate ABI may be needed (significantly deformed or absent cochlea, completely absent nerve tissue).

Putting a Powerful Computer in a Small Patient: Challenges in Providing an ABI

The auditory brainstem implant (ABI) can be viewed simplistically as a digital sound processor made small enough to implant in the brain. Placing this new auditory sensory device in a very young child can be especially challenging, but is necessary to overcome the life handicap of profound hearing loss in the congenitally deaf child. We explain the multidisciplinary problem-solving required to enable ABI placement in the developing nervous system of the young deaf child.

Auditory Brainstem Implant in the Fight Against Childhood Deafness [2015-02-14 Discussion part of ‘Neuroscience of Hearing’ Series @ AAAS 2015 Annual Meeting]
Saturday, 14 February 2015: 3:00 PM-4:30 PM
Room 230C (San Jose Convention Center)

Once a major life-handicapping condition, childhood deafness can be overcome thanks to the innovation of the cochlear implant (CI), a sensory device that assists deaf children in developing listening skills and spoken language despite the fact that the signal conveyed to the brain is quite unlike speech. While the CI is a major breakthrough, many children cannot use a CI because they were born with a deficient or absent cochlear nerve. How can we enable hearing in the absence of necessary elements of the human auditory system? Multidisciplinary synergy across areas of neuroscience, rehabilitation, and education has enabled development of the auditory brainstem implant (ABI). Unlike older devices, an ABI is placed directly on the cochlear nucleus of the brainstem, bypassing the cochlea and auditory nerve. Auditory information is converted to electrical signals that travel from the brain stem to the auditory cortex. As with other surgical innovations such as the CI, intense collaboration among specialists in neuroimaging, neurosurgery, speech-language pathology, audiology, education, and psychology is required to enable this groundbreaking device to bridge the child’s experience with the hearing world and teach the child how to interpret the incoming flood of sensory information. Despite public perception, a device alone cannot cure deafness. Rather, multiple disciplines must join forces to combat this most devastating of communication impairments in preschool-aged children.

Born Without an Auditory Nerve: Auditory Brainstem Implant to the Rescue

Babies born deaf are typically referred for a cochlear implant (CI), an auditory prosthetic device that is surgically implanted in the inner ear. Many children with the CI learn to understand speech without visual cues, acquire spoken language, and are mainstreamed into regular classrooms. Despite the general success of the CI in children, a small proportion of this population is not eligible for the CI because of a deficient auditory nerve or other anatomical deformities. By necessity, such children become reliant on sign language as their primary means to communicate and are typically placed in special school programs for deaf children. Now, another type of implantable auditory device, the auditory brainstem implant (ABI), is undergoing FDA clinical trials to bring hearing to these children. The ABI is similar to the CI but bypasses the cochlea and is placed directly on the cochlear nucleus of the brainstem. The ABI delivers a more scrambled pattern of information to auditory cortex than does the CI, and this pattern is highly degraded and distorted compared to normal hearing. Yet there is emerging evidence that the plasticity of the developing auditory cortex is sufficient so that young deaf children can decipher this scrambled signal and learn to understand speech and language. The focus of this presentation is to discuss emerging communication outcomes in pediatric ABI recipients. Notably, the children enrolled in the pediatric ABI clinical trial are being assessed on the same battery of speech perception tests that is used in a national, multicenter study on pediatric cochlear implantation. Use of this battery allows us to compare auditory development between pediatric CI and ABI users. Data from our center and those from other investigators are showing that auditory development in well-selected children appears to follow a similar trajectory to that of children with CIs. These early data suggest that the child’s brain is able to unscramble the ABI signal in a way that enables the acquisition of spoken language.

When To Choose Auditory Brainstem Implantation Instead of Cochlear Implantation in Children

For any deaf child, earliest intervention is critical. But not all can benefit from a cochlear implant (CI). Even when physiological and anatomical deficits are identified, it is not easy to answer the controversial question of which children should receive a CI or auditory brainstem implant (ABI). We have initiated an exciting new study that will provide important information about when to implant a child with abnormal inner ears with one of these devices to profit from increased sound awareness at the earliest age possible.

How does one make these evaluations in such small patients who cannot communicate directly with us? Along with audiological testing, electrophysiological testing can give us insight as to what the child perceives. New advances in Magnetic Resonance Imaging (MRI) can help identify the potential absence of a cochlear nerve that would preclude benefit from cochlear implantation. However, imaging has not been entirely predictive of a child’s response to CI, and surprisingly, some patients with apparent absence of auditory nerves have had satisfactory responses to CI. Possible reasons for this will be discussed.

Severe inner ear abnormalities may preclude placement of CI or indicate such poor prognosis as to lead to an early decision to implant ABI. Additionally, while a CI is a less invasive procedure, if benefits are not seen quickly, patients may need to be speedily routed into the ABI pathway. In this presentation, examples will be discussed of cases where CI may be appropriate (open cochlea, present but possibly deficient nerve tissue) and where immediate ABI may be needed (significantly deformed or absent cochlea, completely absent nerve tissue).

Putting a Powerful Computer in a Small Patient: Challenges in Providing an ABI

The auditory brainstem implant (ABI) can be viewed simplistically as a digital sound processor made small enough to implant in the brain. Placing this new auditory sensory device in a very young child can be especially challenging, but is necessary to overcome the life handicap of profound hearing loss in the congenitally deaf child. We explain the multidisciplinary problem-solving required to enable ABI placement in the developing nervous system of the young deaf child.

Auditory Brainstem Implant in the Fight Against Childhood Deafness [2015-02-14 Discussion part of ‘Neuroscience of Hearing’ Series @ AAAS 2015 Annual Meeting]
Saturday, 14 February 2015: 3:00 PM-4:30 PM
Room 230C (San Jose Convention Center)

Once a major life-handicapping condition, childhood deafness can be overcome thanks to the innovation of the cochlear implant (CI), a sensory device that assists deaf children in developing listening skills and spoken language despite the fact that the signal conveyed to the brain is quite unlike speech. While the CI is a major breakthrough, many children cannot use a CI because they were born with a deficient or absent cochlear nerve. How can we enable hearing in the absence of necessary elements of the human auditory system? Multidisciplinary synergy across areas of neuroscience, rehabilitation, and education has enabled development of the auditory brainstem implant (ABI). Unlike older devices, an ABI is placed directly on the cochlear nucleus of the brainstem, bypassing the cochlea and auditory nerve. Auditory information is converted to electrical signals that travel from the brain stem to the auditory cortex. As with other surgical innovations such as the CI, intense collaboration among specialists in neuroimaging, neurosurgery, speech-language pathology, audiology, education, and psychology is required to enable this groundbreaking device to bridge the child’s experience with the hearing world and teach the child how to interpret the incoming flood of sensory information. Despite public perception, a device alone cannot cure deafness. Rather, multiple disciplines must join forces to combat this most devastating of communication impairments in preschool-aged children.

Born Without an Auditory Nerve: Auditory Brainstem Implant to the Rescue

Babies born deaf are typically referred for a cochlear implant (CI), an auditory prosthetic device that is surgically implanted in the inner ear. Many children with the CI learn to understand speech without visual cues, acquire spoken language, and are mainstreamed into regular classrooms. Despite the general success of the CI in children, a small proportion of this population is not eligible for the CI because of a deficient auditory nerve or other anatomical deformities. By necessity, such children become reliant on sign language as their primary means to communicate and are typically placed in special school programs for deaf children. Now, another type of implantable auditory device, the auditory brainstem implant (ABI), is undergoing FDA clinical trials to bring hearing to these children. The ABI is similar to the CI but bypasses the cochlea and is placed directly on the cochlear nucleus of the brainstem. The ABI delivers a more scrambled pattern of information to auditory cortex than does the CI, and this pattern is highly degraded and distorted compared to normal hearing. Yet there is emerging evidence that the plasticity of the developing auditory cortex is sufficient so that young deaf children can decipher this scrambled signal and learn to understand speech and language. The focus of this presentation is to discuss emerging communication outcomes in pediatric ABI recipients. Notably, the children enrolled in the pediatric ABI clinical trial are being assessed on the same battery of speech perception tests that is used in a national, multicenter study on pediatric cochlear implantation. Use of this battery allows us to compare auditory development between pediatric CI and ABI users. Data from our center and those from other investigators are showing that auditory development in well-selected children appears to follow a similar trajectory to that of children with CIs. These early data suggest that the child’s brain is able to unscramble the ABI signal in a way that enables the acquisition of spoken language.

When To Choose Auditory Brainstem Implantation Instead of Cochlear Implantation in Children

For any deaf child, earliest intervention is critical. But not all can benefit from a cochlear implant (CI). Even when physiological and anatomical deficits are identified, it is not easy to answer the controversial question of which children should receive a CI or auditory brainstem implant (ABI). We have initiated an exciting new study that will provide important information about when to implant a child with abnormal inner ears with one of these devices to profit from increased sound awareness at the earliest age possible.

How does one make these evaluations in such small patients who cannot communicate directly with us? Along with audiological testing, electrophysiological testing can give us insight as to what the child perceives. New advances in Magnetic Resonance Imaging (MRI) can help identify the potential absence of a cochlear nerve that would preclude benefit from cochlear implantation. However, imaging has not been entirely predictive of a child’s response to CI, and surprisingly, some patients with apparent absence of auditory nerves have had satisfactory responses to CI. Possible reasons for this will be discussed.

Severe inner ear abnormalities may preclude placement of CI or indicate such poor prognosis as to lead to an early decision to implant ABI. Additionally, while a CI is a less invasive procedure, if benefits are not seen quickly, patients may need to be speedily routed into the ABI pathway. In this presentation, examples will be discussed of cases where CI may be appropriate (open cochlea, present but possibly deficient nerve tissue) and where immediate ABI may be needed (significantly deformed or absent cochlea, completely absent nerve tissue).

Putting a Powerful Computer in a Small Patient: Challenges in Providing an ABI

The auditory brainstem implant (ABI) can be viewed simplistically as a digital sound processor made small enough to implant in the brain. Placing this new auditory sensory device in a very young child can be especially challenging, but is necessary to overcome the life handicap of profound hearing loss in the congenitally deaf child. We explain the multidisciplinary problem-solving required to enable ABI placement in the developing nervous system of the young deaf child.

References

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