I wonder about this test.

When I was in my twenties, I had severe vertigo attacks.
I also had dizziness at work. (which at the time was thought to be due to the sonar burglar alarms that were left on during the day there.)

So I had that test then. Spinning in the chair, and also the
blowing air in the ear, with the electrodes on my skull.

The dizziness was centered on my left ear. And the test showed poor response to the test on the left side. The report said I should have been deaf in that ear, and while I have some hearing loss there, I certainly am NOT deaf in that ear at all. I had a very low reading from the electrical leads.

So I wonder how good that test really is. Also after I was given thyroid hormone to normalize my long standing low thyroid, some of that hearing in the ear did improve, but not 100%.

Since then I have had 3 other vertigo attacks that put me in bed over the past 30 yrs. All centered on that side. The last one was triggered by a drug...metformin...that caused some acidosis for me, so I had to discontinue it.

The doctor said I might have some weird damage to that nerve from a blow to the head (abusive childhood) or from the measles or another virus like herpes zoster which I had when young. He thought the nerve could wake up some --be stimulated in some way and cause the vertigo. I have had a couple of severe ear infections on that side too over the years. This is because the brain accommodates to the loss of sensation and then if the nerve wakes up, there is the inability to function until a NEW accommodation occurs. I cannot for example stand up straight with my eyes closed. I can't orient under water, or take showers safely without falling.
But I don't have MS.

So like you my test was not predictive of very much!