A related discussion,
Vertigo was started.
I was diagnosed with Hashitoxicosis (hyperthyroid sometimes/hypothyroid other times) and I had tachycardia and unrelenting vertigo for 16 months prior to diagnosis. It turns out I also have stenosis of the cervical spine, and low vitamin d as well, but I don't know if any of these things could have caused the vertigo.
I had graves disease, but I never suffered from vertigo, just the low B12 and Vit D.
Most thyroid patients do not have vertigo, but there may be a connection. Would replace B12 (and ask about pernicious anemia as cause of low B12) and treat the Graves to get the levels back in the normal range.