What can cause persistent debilitating dizziness for 2 months? it is brought on by activity. brain mri was normal in sept 22. spinal mri shows minor findings as well as herniated disc at c4 - c5. small syrinx below the disc. muscle fatigue also?

Please discuss a Cardiology referral with your physician. Cardiac and Pulmonary conditions should be considered. Watch for fainting, vision change and imbalance.

None of the mentioned test results explain your dizziness, but you do not list any testing of the inner ear. See an otolaryngologist and see if a battery of vestibular studies can uncover the causation.

I agree with Dr. Machinic. In addition, be sure to get some bloodwork done to see if you have anemia, thyroid and/or kidney problems (as well as checking for other abnormalities). Also check that you have no drug interactions between any medications that you are taking (prescription and/or over the counter): try this interaction checker: https://www.drugs.com/drug_interactions.html