Hello.
Thank you for your query at DoctorSpring.com.
I can understand your concern and will try to help you in the best possible way.
Vertigo can be a presentation of many diseases. It can be because of ear disease/ brain disease/ metabolic/ balance system disorder etc. To treat it, we should know the correct diagnosis. In order to reach a correct diagnosis, I need more information and perhaps a few other tests.
As your MRI brain is normal, it rules out the possibility of organic brain lesions including tumors, aneurism etc. Allergy does not cause vertigo and sinuses can be seen in cuts of MRI brain.
Do you have symptoms of sinusitis such as a nose block, nasal discharge, facial pain, or fever ?

Inner ear disease or infection can cause vertigo but we need to evaluate this to find the correct diagnosis.
I am providing you a vertigo evaluation form. Please open it. Copy and paste the contents in a new document and you can fill it in the same. Please upload that filled form in the follow-up. This form can be accessed here:
https://docs.google.com/document/d/1r0AqpH9l0__umEzxuk4dWv1t9WfvKEppGehOl2GHsT4/edit?usp=sharing

A sample filled form also is present, to help you fill your own. You can see it for reference, here:
https://drive.google.com/file/d/0B-8ZMSsBayxJa2xwc1FLREpWV0hQT1pESjNTRElJa1dHNEpz/edit?usp=sharing

If you have any hearing test or eye test or any other related investigation done in past, please upload the report.

Hope this was helpful. Feel free to ask any further queries.
Thank you.

Regards,
Dr. Sunil Jalan MBBS, DLO, MS (ENT), DNB, DAA.