I agree with Mrs D...there is a big connection between your perceptions of your whereabouts, vertigo, etc., and your cognitive functions.

I can't claim to understand it all fully. All I know is that as my daughter's visual system improves, so does her ability to concentrate for longer periods, her ability to understand complex verbal instructions, perform calculus equations, etc. Not to mention her ability to read for long periods and remember what she's read

In other words, perhaps your brain power was being consumed by helping you balance and perceive your surroundings. There wasn't enough left over for higher cognition.

For whatever reason I have become the board's cheerleader for vision therapy...so I have to suggest that if your ears are testing ok, then perhaps you need to get tested for ambient vision issues. Google post traumatic vision syndrome and you will see many of the symptoms you list.

In my daughter's case she continued to score 20/20 on vision tests but we now know she was actually seeing double for most of a year without really realizing it. I know it sounds too weird to be true. The vision therapist had her walk a straight line and we were STUNNED at how much she was compensating in her body to do so. He put a pair of sample prism glasses on her and her entire body straightened up.

It just might be worth some research for you. You might also google NORA vision.

All the best-

PS I don't know what any of this has to do with your stuffy nose/sudden improvement...sorry if I'm off topic for you.