University of Colorado at Boulder: Department of Speech, Language, and Hearing Sciences Summary of Current Research lead by Dr. Anu Sharma (from their website)
http://www.colorado.edu/slhs/eeglab/research.html
“We are investigating the maturation of the human central auditory pathways in normal hearing children and in children with hearing impairment, with a view of better understanding the effects of sensory deprivation on central auditory development.
The primary research focus in our laboratory is to investigate the effects of auditory deprivation on the development, deterioration, and plasticity of the human central auditory system. To this end, we are examining cortical auditory evoked potentials in normal-hearing children, congenitally deaf children who wear cochlear implants, children with auditory neuropathy, and children and adults with hearing impairment. Our goal is to estimate the time interval over which the human auditory system remains relatively non-degenerate and/or highly plastic in the presence of auditory deprivation. Knowledge of this time course of deprivation may enable us to determine the best time to place a cochlear implant into a deaf child.”
My version of the benefits of this study per conversations with the researchers; I've also included a summary of Aubrey's results
Their testing is looking at brain development at the level of the cortex in hearing loss and neuropathy patients. The cortex is the area of the brain that processes sound. The testing can record cortical potentials like an ABR, but further up the brain in the cortex. UC-Boulder is the first in the US to do this kind of CAEP testing looking at P1 latencies specifically in AN children. Previously this had only been done in Australia.
The results of this testing tells us the following:
· The maturation of the brain.
o This is more critical in younger AN patients to help determine if the neuropathy is a result of neuromaturation that may resolve itself as the baby gets older and the brain matures. Common in pre-mature babies.
More importantly for us, the testing can:
· Tell us if the cortex is getting enough stimulation/development from the hearing aids
o Aubrey’s cortex measures fell within normal limits meaning that she has received enough cortex development via her hearing aids. It’s not understood how clear the sound has been, but the amplification from the aids has provided enough sound to get through to enable normal cortex development. This is huge! Kids who fall within this range also tend to respond well to an implant.
· Tells us the severity of the dys-synchrony - where Aubrey falls on the Auditory Neuropathy Spectrum:
o Normal Cortical Measures = mild neuropathy/dyssynchrony
o Delayed Cortical Measures = moderate neuropathy/dyssynchrony
o Abnormal Cortical Measures = profound neuropathy /dyssynchrony
- It was indicated that Aubrey falls within the mild to moderate range per the statement below about the differences between the two ears.
· Each ear can be tested separately to see if the cortical measures are different between the ears. This could help us determine which ear would receive more benefit from a CI.
o When testing each ear separately, Aubrey’s right ear fell within normal limits. However, her left ear was just outside of normal, thus falling in the delayed measure. This means the left ear will benefit most from a cochlear implant. Because this ear falls outside normal measures, it will become more difficult for Aubrey to keep up with the complexity of speech/language and social interaction as she ages.
· Overall, this testing could give us more information for determining if we need to change our current course of action and help us feel more confident in our decision regarding implanting.
o It’s interesting to note that Dr. Sharma has tested cortical measures in AN kids pre and post implant. Test results pre-implant in some cases showed jumps across the measures - normal to delayed and back, for example. Once implanted, normal cortical measures were present without jumps, thus meaning the child was finally receiving a clear, consistent signal. As we know, each child is different and this is not always going to be the case. But, it does show that when a CI works for an AN child it’s truly a beautiful thing!
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