Monday, June 22, 2009

Sedated ABR

This week Ben had his first sedated ABR (Auditory Brainstem Response). The ABR evaluates how well sounds travel along the hearing nerve pathways from the ear to the brainstem (i.e how well he hears).

The ABR monitors changes in brain activity as repetitive clicking sounds are sent through the ear. The audiologist places four small stickers on Ben's head, chest, and ear lobes, connected to leads going into a computer. Sounds are be sent through an earphone to each ear separately while a computer analyzes the changes in the brain wave pattern in response to sounds.

In order for the results to be accurate, the brain needs to be relaxed. When Ben was younger, he was able to sleep peacefully for the ABR. Each time he would twitch or suck on his pacifier, we would see a change in his brain waves on the computer screen. Now, to have Ben's brain relaxed enough and for long enough, he needs to be sedated.

Ben doesn't mind the process at all- except that we had to starve him for 6 hours before the sedation. Nurses put numbing cream on his skin in several places so the I.V wont hurt as much.

A Sedation team administers the medication and Ben falls peacefully asleep. The hospital wont allow parents to stay with their children once they are fully sedated. Mom and dad have a few hours to wonder, eat and worry.

According to the ABR, Ben's hearing has not changed since his last ABR three months ago. We had a small bit of hope (or wishful dreaming) that his hearing would have improved somehow. But, we are also glad to have the left ear working just as strong. We know that with EVA
hearing loss is progressive. We would hate to have the hearing he currently has decline before he is implanted. In this case, December seems so far away.