What is the ABR test?

[sally]

Can someone tell me what the ABR test is?  I've been recently diagnosed with an AN and they are having me do an ENG.  I only have to wait 7 weeks for that appointment! sally

[russ]

Sally
  You can do a web search at Google but off the top of my head I believe one is placed in a sound booth after being wired for an EEG ( brain wave test ), the patient is asked to be quiet and relax and actually try to sleep, then tiny licking noises are played into the ear. The amount of measured delay befor the sound reaches the brain indicates whether the problem causing symptoms is in the middle or inner ear. The longer the delay, I think the less likelihood of an acoustic neuroma or it being more exteriorly located ( still in the superior Inner Auditory canal ).
  Remember this is a forum of ametuers and pts, however. Personally, I see no reason for the test now that we have MRI to rule in/out ANs and reveal their locations but you already report having one. ABR can help Dx Menieres Disease.
  Please forgive me if I'm wrong in my explanation. Just too tired to go web searchin right now!
  Russ 

[stein78]

"Auditory brainstem response" - When I had my test, I was told that they were setting a baseline on my hearing before surgery (how the brain responds).  This way, if they damaged the hearing nerve during surgery, they would know it instantly (lack of response).  It's kind of hard to tell your surgery team that you all of a sudden can't hear anymore while they are performing surgery.    Not sure if I am explaining that the best, but hopefully you get the idea.

[tgentile]

For what its worth, my ABR pre-surgery and during surgery showed that I'd have significant hearing loss.

I went for my hearing test last Wednesday (3 weeks post-op) and it showed minimal hearing loss as compared to the pre-surgery test.

Goes to show you every case is different. Every outcome is different. I'm happy the AN is gone and I can hear. (lots of ringing though, but who cares. I can hear!)