Expert: Harriet B Jacobster, Au.D. - 5/20/2009

Question
I just got results from an ENG, ECOG and hearing testing.  Good news I can hear, bad news the results from the other tests all came back abnormal.  Doctor is stumped, Ordered an ABR test. My question is this, what will the test show?  Example: if it comes back normal or abnormal, what could be the cause of my severe vertigo, dizziness, off balance...and also intermetant head aches, going on 2 months now

Answer
Hi Lesley,
Auditory Brainstem Response Audiometry (ABR) is a test of neural synchrony of the 8th (auditory) cranial nerve.  This test, if done properly, usually indicates an abnormality in the way the nerve transmits impulses from the auditory system to the brain. He is most likely looking for a benign growth on the nerve known as an acoustic neuroma, or more appropriately, a vestibular schwannoma.

As far as the cause of your symptoms, there are literally hundreds of reasons for them ranging from a virus in the inner ear to a tumor to MS.  There is no reason for your doctor to be "stumped" after only these few tests.  Differential diagnoses of vertigo, disequilibrium and headache include blood tests, complete neurological evaluations, and imaging tests such at CT and/or MRI.  

Hope this helps.
Harriet B. Jacobster, AuD
Board Certified in Audiology