I Have Had Dizziness And Disorientation In Crowded And Loud

I have had dizziness and disorientation in crowded and loud and dark places since June 2015. My neurologist ordered an MRI, CT angiography, and results were negative, also had test for vertigo with an ENT and they were negative. Next test that I have scheduled is evoked potentials, and I think that is for MS.
I am 60, good health, not on any prescription medication, a little overweight. Any suggestions as to what this may be?