Hello I am Dr Ravinder Sharma ENT surgeon.
I would say that you need a detailed history about your dizziness
and a complete neurotological examination and some tests to come down to diagnosis. As your tests are normal I would like to inquire about the characterstics of your dizziness again
How do you feel during a episode of vertigo
-- head is spinning or walls are moving or you get light headed ness or you sway on one side while walking ?
Has there been nausea
during dizzy spell?
Is it continuous or it comes and goes?
Do you experience any ringing sensation in ear?
Do you have headache during dizziness?
What is the duration of the episode of dizziness(if it is episodic)? Is it in seconds, minutes , hours or days?
Are you on any medications?
What makes dizziness better?
What makes it worse?
Do you have anything significant that you experience with it?
Do write back to me with these answers so that I can help you further. Dizziness is a complex symptom and can be because of the disease of ears, brain, cervical spine
, eyes and cardiovascular system.