Vestibular Testing

[jbbrown15]

Hi.  It's been a long while.  I have a 2.9 cm tumor that was radiated in 2010.  The tumor is dead, but I've had issues with increased intracranial pressure ever since.  It was a slow recovery, but I got back to a specialized legal career (tax lawyer).

Beginning in mid-January vertigo has come back and debilitated me.  I've been out of work for 2 weeks.

I've seen several doctors and had vestibular testing done.  There was almost no response to the ice water caloric test, so the doctor said that my vestibular nerve is essentially dead.  The best theory for why I'm having trouble now is that the nerve damage is a late effect of radiation.

I'd love to hear from people who have had the caloric testing show little to no function, and how they have done short and long term.

Thanks!

JB

[ANGuy]

I took a battery of vestibular tests, all with acronyms I don't remember anymore, but are commonly used.  I had warm and cold water flushed through my ears as you did.  I have a 1cm tumor and have not had any treatment.

My overall testing showed my vestibular function to be "about 50%" in the words of my Dr at that time, about 18 months ago.

That is my background just to give you some idea in the differences in our circumstances.  My vestibular symptoms have been sudden, terrible attacks that subside with drug intervention (benzodiazpines, antihystmeines).  I have had probably a half dozen of these attacks that lasted a day or two over about a ten year period.  I haven't had one in a couple of years and my Dr figures I won't get anymore since my vestibular function is so far gone there isn't enough signal left to make me sick.

[UpstateNY]

There are two vestibular nerve branches in each ear, the superior vestibular nerve and the inferior vestibular nerve.  According to my physician, the caloric test can be used to test the superior vestibular nerve and the VEMP can be used to test the inferior vestibular nerve.

The facilities local to me only offered the caloric test, that I had taken to help determine which vestibular nerve my tumor was growing from.  The location was not completely evident from the MRI.  If the AN was growing from the inferior vestibular nerve, it was believed there would be less chance of facial nerve damage (since I took the microsurgical approach) being that the tumor would be located further away from the facial nerve and easier to remove.  My caloric test showed an 18.7% unilateral weakness in my AN ear.  Typically, a weakness < 30% is more consistent with inferior nerve involvement.  This means if I had taken the VEMP test, I would have expected to see a much more significant weakness in the inferior nerve of my AN ear.  At that time, I did have some lightheadedness when walking or running.

After removal of the AN, it was confirmed by the surgeon that the tumor was growing from the inferior vestibular nerve.  This was consistent with the caloric test results.  When I woke up after surgery I had no nausea or dizziness, my balance was no worse than prior to surgery, and the lightheadedness when moving quickly improved in a couple of days.  This lack of dizziness post surgery would seem to indicate that my inferior vestibular nerve had near 100% weakness prior to surgery.  I am now just 6 weeks past surgery (transcochlear, so they cut both vestibular nerves on the AN side) and I would say my balance is very close to normal with everyday activities. 

It sounds like the VEMP test may provide you with more information, so may be worth discussing with your physician.

[mcrue]

What about the ABR test?

[ANGuy]

Interesting info Upstate.  I didn't pay too much attention to details, just the general "50%" from the Dr at the time.  I did have the rotating chair test (VEMP?) and an ABR and maybe a couple of others.  I did have a new type of ABR that they were doing some research on along with the standard one.  I'll ask about the superior/inferior issue when I go back in Jan 17.