IF it's CVT, it
could be very serious.
Google:
cerebral venous sinus thrombosis
Wikipedia may be a good
starting point, but I would research much further than that.
What does the report from the radiologist say? You don't mention what kind(s) of doctors these were, their expertise, or any corroborating testing.
If it were me, I would want to know. I think I would start checking out hospitals and their expertise diagnosing and treating CVT and get an appointment with the best specialist I could find, if only to rule some things out.
Doc