Auditory neuropathy: Description, Causes and Risk Factors:
A disorder of hearing in children characterized by sensorineural hearing loss for pure tones, reduced word discrimination disproportionate to the pure-tone loss, normal outer hair cell function as determined by measurement of otoacoustic emissions, and absent or abnormal auditory brainstem response.
Auditory neuropathy is a unique disorder of hearing in which the inner ear itself may be perfectly normal but speech cannot be heard clearly enough for a child to develop normal speech and language. The problem is in the cochlear nerve itself and its inability to clearly transmit sounds received by the inner ear to the brain where hearing and interpreting of speech actually occurs. If the auditory nerve has neuropathy, a child may be aware of sounds but the signal will be very poor. The result is that a child will react to sound and give no evidence to the parents that there is a hearing problem until it becomes clear at two years of age or older that despite hearing sounds, no speech has developed.
Some children who have been diagnosed with auditory neuropathy experience certain health problems as newborns, or during or shortly before birth. These problems include jaundice, premature birth, low birth weight, and an inadequate supply of oxygen to the unborn baby. In addition, some drugs that have been used to treat medical complications in pregnant
women or newborns may damage the inner hair cells in the baby's ears, causing auditory neuropathy.
It can affect people of all ages, from infancy through adulthood. The number of people affected by auditory neuropathy is not known, but the condition affects a relatively small percentage of people who are deaf or hearing-impaired.
People with auditory neuropathy may have normal hearing, or hearing loss ranging from mild-to-severe; they always have poor speech-perception abilities, meaning they have trouble understanding speech clearly. Often, speech perception is worse than would be predicted by the degree of hearing loss. For example, a person with auditory neuropathy may be able to hear sounds, but would still have difficulty recognizing spoken words. Sounds may fade in and out for these individuals and seem out of sync.
Audiologists, use a combination of methods to diagnose auditory neuropathy. These include tests of auditory brainstem response (ABR) and otoacoustic emissions (OAE). The hallmark of auditory neuropathy is a negligible or very abnormal ABR reading together with a normal OAE reading. A normal OAE reading is a sign that the outer hair cells are working normally.
An ABR test monitors brain wave activity in response to sound using electrodes that are placed on the person's head and ears. An OAE test uses a small, very sensitive microphone inserted into the ear canal to monitor the faint sounds produced by the outer hair cells in response to stimulation by a series of clicks. ABR and OAE testing are painless and can be used for newborn babies and infants as well as older children and adults. Other tests may also be used as part of a more comprehensive evaluation of an individual's hearing and speech-perception abilities.
While there is no known cure for Auditory neuropathy, assistive listening devices (ALDs) can help kids with auditory neuropathy make sense of sounds and develop language skills. You'll work with a Medical team to determine which devices are right for your child. Treatment for auditory neuropathy depends on how severe it is and the age of the child at diagnosis.
A crucial part of making any device effective is ongoing therapy with a speech-language pathologist
, who helps children with hearing loss develop speaking and hearing skills.
Cochlear implant: A cochlear implant is a device that has internal and external parts and is designed to replace the portions of the ear that aren't working properly. Parts of the implant are placed inside the head during a surgical procedure. Another part of the implant is worn on the outside, behind the ear. With training and therapy, a child with a cochlear implant can learn to hear and speak well. Cochlear implants typically aren't considered until after kids are at least 1 year old and have tried other ALDs without success. Cochlear implants have helped many people with auditory neuropathy, but ongoing therapy after the surgery is crucial for them to be effective. Not all kids with auditory neuropathy are candidates for the implants.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.