Surgery Day
8 years ago
Another important characteristic is that, most people with LVAS experience sudden hearing loss following a minor head injury or other activity which causes increased intra-cranial pressure (increased cerebrospinal fluid pressure). In one study the figure was 85.7% while another study reported 61%. A mild bump on the head, tripping or falling down or even jumping can jar the head enough to result in more hearing loss. Also, sudden hearing loss can follow a minor illness such as a common cold, strenuous exercise or a sudden change in barometric pressure.
In one study of 12 children with LVAS, five had sudden hearing losses. Three of the episodes followed relatively minor head injuries. The fourth occurred while forcefully playing a trumpet, and the fifth occurred immediately after an airplane flight.
In another case, a six-year-old child ran into a goal post while playing soccer and hit his head on the left side. This resulted in sudden hearing loss in the left ear. Three years later, after mild head injury while on the school playground, the child again reported an immediate hearing loss, this time in the right ear. An audiogram done that same day revealed severe to profound hearing loss in the right ear and profound hearing loss in the left. A CT scan revealed bilateral large vestibular aqueducts with no other inner ear abnormalities. Over the next month, hearing fluctuated between moderate and severe.
After episodes of sudden hearing loss, hearing may recover to the previous level, or much more commonly, it may recover partially to a new "normal." One girl with LVAS had characteristic attacks of sudden hearing loss following minor head trauma, common colds or exercise. Her high frequency hearing is now almost non-existent but her low-frequency hearing tends to recover shortly after each episode.
Hearing loss in LVAS generally follows a step-wise pattern. Each incident causes the hearing to drop another step. The hearing loss will follow one of two patterns. One is a gradual progressive stepwise hearing loss, but with fluctuations. The other is sudden bouts of hearing loss of at least 15 dB that may fluctuate to profound levels following minor head injuries or fluctuations in the pressure of cerebrospinal fluid (CSF). Usually these acute drops in hearing do not recover to previous levels. The end of this downward progression typically is profound hearing loss.
What is the vestibular aqueduct?
The vestibular aqueduct is the bony canal that links the inner ear with the fluid that surrounds the brain. In adults the vestibular aqueduct is narrow and shaped like the letter 'J'. However, when a baby is in the womb the vestibular aqueduct starts off being short, wide and straight before it develops, before birth, into a longer, narrower, J-shaped tube. The terms 'enlarged', 'wide' or 'dilated' refer to vestibular aqueducts that have not developed fully, and remain short and wide. In this document we will refer to an enlarged vestibular aqueduct.
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How does an enlarged vestibular aqueduct affect hearing?
An enlarged vestibular aqueduct can cause progressive or fluctuating deafness. (In other words, deafness that gets worse over time or changes from one level to another and back again.)
No one is quite sure why this happens. One explanation is that an enlarged vestibular aqueduct may allow the various pressure changes in the fluid around the brain to pass through to the inner ear (known as the cochlea), possibly affecting the hearing system.
The type of deafness usually associated with an enlarged vestibular aqueduct tends to be worse in the higher frequencies and usually affects both ears. Some people also experience a feeling of dizziness and imbalance (vertigo), and a general lack of co-ordination. It is difficult to know if your child's deafness will change over time or stay the same. However, the specialist may suggest that your child avoids certain sports, including contact sports and those that involve being exposed to changes in pressure (such as scuba diving). This is because it is thought that severe changes in pressure or a minor head injury can lead to an increase in deafness in children with an enlarged vestibular aqueduct.
While I have a cochlear implant in my right ear, I want you to know that I continue to depend on the hearing aid that I wear on my left ear. Interestingly, there are some sounds that I do not hear well with my cochlear implant that I hear well with my hearing aid. The same thing is also true of my implant. There are sounds that I hear very well with the implant that I do not hear well with the hearing aid. One thing is certain, with the combination of both devices working together I hear much better than I did before as is evidenced by my speech recognition testing.
”. I have really been researching a lot about cochlear implants and specifically about the benefits of binaural hearing. It seems to me that Lily has nothing but good things to gain from hearing from both ears. From what I have read, binaural hearing helps young children acquire language more naturally and allows for better speech perception, more natural and balanced sound, and better sound localization abilities. For those reasons, I have chosen to seek out your advice and expertise. I just want my daughter to live as normal a life possible and it seems to me that a cochlear implant will help us realize that dream for her.
We have chosen at this time to pursue Auditory-Verbal Therapy with Lily and we are very lucky to have Janet Kahn as our therapist. We will officially begin therapy on September 11. Part of my desire in choosing AV is to have Lily a part of the hearing world as much as possible. I have my doubts that this will be possible with Lily only having limited hearing in one ear. I don’t want her entire childhood revolving around rigid therapy that keeps her from learning in the most natural way possible, which to me is through play and acquiring language from listening to the world around her.
If Lily does not qualify for a cochlear implant we may change gears completely in regards to how we choose to communicate with her. It seems too hard on her (and by this I mean that I really think pushing AV therapy on her when she understands so little could break her spirit and that is the last thing I want to do) to continue on the AV path if she does not receive more access to hearing. We will likely switch to a Total Communication education for her so that we may fill her up with language as quickly as possible. I feel like we have already lost so much time. This choice means that Lily’s entire future will be changed dramatically and her choice of education, employment, and relationships with others will be very limited. This is obviously not what we want for our little girl.