Interview with Chris Hoffman M.S. CCC-A, F-AAAAtlantic Rehabilitation Institute, Morristown Memorial Hosptial
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Topic: Auditory Neuropathy
Beck: Hi Chris. Thanks for joining me today. It's great to speak with you again...I think we last addressed auditory neuropathy with you in early 2003. However, for the new readers, before we get into auditory neuropathy, please tell me a little about yourself?
Hoffman: Hi Doug. It's great to talk with you again as well! My undergraduate degree was in Audiology and Speech from Stockton State College in South Jersey and I received my graduate degree in Educational Audiology, from Penn State in 1986. I went right into my CFY and have been practicing ever since. My position here at Morristown Memorial Hospital is clinical audiologist.
Beck: Okay, great. Let's get into Auditory Neuropathy (AN), and by the way, the other name for AN is auditory dys-synchrony, right?
Hoffman: Yes, the names are used interchangeably.
Beck: Let's start with the working definition of auditory neuropathy. What is it and how do you diagnose it?
Hoffman: I consider auditory neuropathy a dys-synchrony in the auditory mechanism. In essence, AN indicates that information from the cochlea is not being transmitted in an efficient manner along the auditory pathway. I believe Dr. Arnold Starr described the electrophysiologic and psychoacoustic findings of AN in 1991.
Beck: Okay. So, you're saying there is some physiologic interruption or distortion between the cochlea and the temporal lobe?
Hoffman: Correct.
Beck: Is there a specific anatomic site that correlates with AN?
Hoffman: No I don't think so, if there is a specific site, it's pretty elusive! The closest we can offer is that it's along the auditory pathway. Dr. Arnold Starr has reported that possible sites could occur within the nerve itself, at the synapse or at the inner hair cell level. AN is really fascinating and it can manifest as different symptoms across different patients.
Beck: What are the red flags that makes one think, "Ahhhhh - this might be auditory neuropathy?" What do you look for in the history and with respect to ABR and OAE?
Hoffman: What we typically see in young children, are present and robust OAE's, absent middle ear reflexes, absent ABR responses and a lack of benefit from conventional amplification.
Beck: And just to review ...We know that normal OAEs indicates that hearing at the level of the peripheral auditory nervous system is better than 25 or 30 dB HL and of course in that situation you would expect a normal ABR.
Hoffman: Yes, that's correct.
Beck: Why would you do an ABR on somebody with normal OAEs?
Hoffman: Good question. Let's use an example of a newborn. Suppose they pass the OAE screening in the hospital. However, as they develop they may not demonstrate expected developmental milestones; such as responding or startling to sound, localization of sound etc. At that point, the parents or their physicians will refer to us, and that's typically when we'll do the ABR and other behavioral tests with those children.
Beck: Okay. So now we have a normal OAE, we have an absent or poor morphology on an ABR, and where do we go from there? Does that instantly make the diagnosis or must there be radiologic studies?
Hoffman: Generally our patients will go through a battery of tests including; radiologic studies, blood work, in-depth medical evaluations, and in-depth objective and subjective audiologic evaluations too.
Beck: So in some respects this is a diagnosis based on exclusion? In other words, there is a recognizable diagnostic pattern, and nothing else fits?
Hoffman: Correct. AN is diagnosed after we've tried everything, and nothing else makes sense!
Beck: I can recall some controversy regarding children with auditory neuropathy and whether or not to put hearing aids on them and whether or not to proceed with cochlear implants?
Hoffman: I think there is always going to be a controversy when we're discussing children! I believe we all have the child's best interest at heart and there's just going to be differing opinions, which I think of as a strength, rather than as a shortcoming! It forces us to work together, and evaluate all the available information before deciding on any course of action when it is related to children. When dealing with any patient, and especially children, we (as audiologists) will take the least invasive approach as possible.
With children, there is a fear of not providing adequate auditory/linguistic information during the critical language learning period. The first step is to appropriately fit the patient with hearing aid(s). If no significant change or improvement in auditory awareness or development is seen by an evaluation team; including; audiologists, physicians, educators and parents, then the option for cochlear implantation is considered.
Beck: Can you tell me about any specific children you've worked with who have been diagnosed with AN?
Hoffman: Sure, I have worked with children diagnosed with AN. One child was diagnosed at the age of 12 months. At that time she was fitted with two hearing aids and wore them for 6 months. During that time, no objective or subjective changes were observed in her auditory awareness. Unaided she showed no awareness of sound and while wearing her hearing aids, the same lack of awareness was observed. At 18 months of age she received a cochlear implant, and during her initial mapping she responded consistently to speech and electrical stimulation. She is now 3 years old, enrolled in a pre-school program and is speaking in age appropriate sentences.
Beck: It must've been very hard for the parents to keep placing the hearing aids on her for 6 months without seeing any progress?
Hoffman: Yes I agree. The parents wanted to make sure they had considered all possibilities before having any surgical intervention.
Beck: Here's a difficult question - Do you think some of the children that have auditory neuropathy and get cochlear implants, might eventually have presented with normal or near-normal hearing after they aged a few more years?
Hoffman: That is a good question. I haven't had much experience with that age group with auditory neuropathy yet. I have spoken with other professionals and there have been some children that might present with fluctuating hearing loss, where sometimes they might show a mild to moderate hearing loss and sometimes severe, sometimes even close to normal. Nonetheless, I am not aware of any AN patient who didn't respond to sound, and then later presented with normal hearing. I'm not saying it doesn't happen, but I haven't heard of it. Keep in mind that all patients go through a rigorous evaluation before cochlear implant candidacy is determined. If a child presents with fluctuating hearing loss, or mild to moderate hearing loss and/or is acquiring speech and language as normally expected, he/she would not be considered a cochlear implant candidate.
Beck: How many AN children have you implanted?
Hoffman: We're just now working with our second pediatric cochlear implant patient with auditory neuropathy.
Beck: What are your thoughts as far as rehab and long-term outcomes for the implanted child with AN?
Hoffman: Research has indicated that in these children, cochlear implants provide a meaningful and consistent auditory signal. Theoretically, if the child is implanted early enough, they will likely be able to develop speech and language on schedule with age appropriate norms.
Beck: How do you proceed with Aural Rehabilitation for these children?
Hoffman: In general, all patients should be placed in an educational environment that emphasizes auditory & oral skills. Typically, with very young children I recommend introducing sound stimulation in an enriched language and sound environment, as well as the structure of auditory training with either an auditory verbal therapist (AVT) or speech language pathologist. I think the most important issue is to remember that the implantation of the cochlear implant, by itself will not solve or "cure" the problem (although it is an important step for properly diagnosed and identified people). The process of a structured Aural Rehabilitation program must be addressed thoroughly and effectively so one can learn to use the cochlear implant to its fullest potential, and this takes time and is an ongoing commitment.
Beck: Thanks so much for your time and knowledge.
Hoffman: Thank you too Doug. It's been a lot of fun for me too.
Hoffman: Hi Doug. It's great to talk with you again as well! My undergraduate degree was in Audiology and Speech from Stockton State College in South Jersey and I received my graduate degree in Educational Audiology, from Penn State in 1986. I went right into my CFY and have been practicing ever since. My position here at Morristown Memorial Hospital is clinical audiologist.
Beck: Okay, great. Let's get into Auditory Neuropathy (AN), and by the way, the other name for AN is auditory dys-synchrony, right?
Hoffman: Yes, the names are used interchangeably.
Beck: Let's start with the working definition of auditory neuropathy. What is it and how do you diagnose it?
Hoffman: I consider auditory neuropathy a dys-synchrony in the auditory mechanism. In essence, AN indicates that information from the cochlea is not being transmitted in an efficient manner along the auditory pathway. I believe Dr. Arnold Starr described the electrophysiologic and psychoacoustic findings of AN in 1991.
Beck: Okay. So, you're saying there is some physiologic interruption or distortion between the cochlea and the temporal lobe?
Hoffman: Correct.
Beck: Is there a specific anatomic site that correlates with AN?
Hoffman: No I don't think so, if there is a specific site, it's pretty elusive! The closest we can offer is that it's along the auditory pathway. Dr. Arnold Starr has reported that possible sites could occur within the nerve itself, at the synapse or at the inner hair cell level. AN is really fascinating and it can manifest as different symptoms across different patients.
Beck: What are the red flags that makes one think, "Ahhhhh - this might be auditory neuropathy?" What do you look for in the history and with respect to ABR and OAE?
Hoffman: What we typically see in young children, are present and robust OAE's, absent middle ear reflexes, absent ABR responses and a lack of benefit from conventional amplification.
Beck: And just to review ...We know that normal OAEs indicates that hearing at the level of the peripheral auditory nervous system is better than 25 or 30 dB HL and of course in that situation you would expect a normal ABR.
Hoffman: Yes, that's correct.
Beck: Why would you do an ABR on somebody with normal OAEs?
Hoffman: Good question. Let's use an example of a newborn. Suppose they pass the OAE screening in the hospital. However, as they develop they may not demonstrate expected developmental milestones; such as responding or startling to sound, localization of sound etc. At that point, the parents or their physicians will refer to us, and that's typically when we'll do the ABR and other behavioral tests with those children.
Beck: Okay. So now we have a normal OAE, we have an absent or poor morphology on an ABR, and where do we go from there? Does that instantly make the diagnosis or must there be radiologic studies?
Hoffman: Generally our patients will go through a battery of tests including; radiologic studies, blood work, in-depth medical evaluations, and in-depth objective and subjective audiologic evaluations too.
Beck: So in some respects this is a diagnosis based on exclusion? In other words, there is a recognizable diagnostic pattern, and nothing else fits?
Hoffman: Correct. AN is diagnosed after we've tried everything, and nothing else makes sense!
Beck: I can recall some controversy regarding children with auditory neuropathy and whether or not to put hearing aids on them and whether or not to proceed with cochlear implants?
Hoffman: I think there is always going to be a controversy when we're discussing children! I believe we all have the child's best interest at heart and there's just going to be differing opinions, which I think of as a strength, rather than as a shortcoming! It forces us to work together, and evaluate all the available information before deciding on any course of action when it is related to children. When dealing with any patient, and especially children, we (as audiologists) will take the least invasive approach as possible.
With children, there is a fear of not providing adequate auditory/linguistic information during the critical language learning period. The first step is to appropriately fit the patient with hearing aid(s). If no significant change or improvement in auditory awareness or development is seen by an evaluation team; including; audiologists, physicians, educators and parents, then the option for cochlear implantation is considered.
Beck: Can you tell me about any specific children you've worked with who have been diagnosed with AN?
Hoffman: Sure, I have worked with children diagnosed with AN. One child was diagnosed at the age of 12 months. At that time she was fitted with two hearing aids and wore them for 6 months. During that time, no objective or subjective changes were observed in her auditory awareness. Unaided she showed no awareness of sound and while wearing her hearing aids, the same lack of awareness was observed. At 18 months of age she received a cochlear implant, and during her initial mapping she responded consistently to speech and electrical stimulation. She is now 3 years old, enrolled in a pre-school program and is speaking in age appropriate sentences.
Beck: It must've been very hard for the parents to keep placing the hearing aids on her for 6 months without seeing any progress?
Hoffman: Yes I agree. The parents wanted to make sure they had considered all possibilities before having any surgical intervention.
Beck: Here's a difficult question - Do you think some of the children that have auditory neuropathy and get cochlear implants, might eventually have presented with normal or near-normal hearing after they aged a few more years?
Hoffman: That is a good question. I haven't had much experience with that age group with auditory neuropathy yet. I have spoken with other professionals and there have been some children that might present with fluctuating hearing loss, where sometimes they might show a mild to moderate hearing loss and sometimes severe, sometimes even close to normal. Nonetheless, I am not aware of any AN patient who didn't respond to sound, and then later presented with normal hearing. I'm not saying it doesn't happen, but I haven't heard of it. Keep in mind that all patients go through a rigorous evaluation before cochlear implant candidacy is determined. If a child presents with fluctuating hearing loss, or mild to moderate hearing loss and/or is acquiring speech and language as normally expected, he/she would not be considered a cochlear implant candidate.
Beck: How many AN children have you implanted?
Hoffman: We're just now working with our second pediatric cochlear implant patient with auditory neuropathy.
Beck: What are your thoughts as far as rehab and long-term outcomes for the implanted child with AN?
Hoffman: Research has indicated that in these children, cochlear implants provide a meaningful and consistent auditory signal. Theoretically, if the child is implanted early enough, they will likely be able to develop speech and language on schedule with age appropriate norms.
Beck: How do you proceed with Aural Rehabilitation for these children?
Hoffman: In general, all patients should be placed in an educational environment that emphasizes auditory & oral skills. Typically, with very young children I recommend introducing sound stimulation in an enriched language and sound environment, as well as the structure of auditory training with either an auditory verbal therapist (AVT) or speech language pathologist. I think the most important issue is to remember that the implantation of the cochlear implant, by itself will not solve or "cure" the problem (although it is an important step for properly diagnosed and identified people). The process of a structured Aural Rehabilitation program must be addressed thoroughly and effectively so one can learn to use the cochlear implant to its fullest potential, and this takes time and is an ongoing commitment.
Beck: Thanks so much for your time and knowledge.
Hoffman: Thank you too Doug. It's been a lot of fun for me too.
