Basal ganglia and corpus callosum

41 f
I have had migraine for 11 yrs and when I first got them many of my MRIs would show calcifications in my basal ganglia and at first the ED Dr would tell me I had a stroke... after further checking it out they would always back track and say no it was a calcification.   This happened probably a dozen times. Last July I had a TIA which was misdiagnosed I could not speak properly or stay concious so the Dr (who had decided I was a drug seeker due to yrs of migraines and because I am a patient at a pain clinic (but I am very careful with my meds and typically take less than prescribed never more) he diagnosed me as a drug overdose... which was not true)  a MRI done a few months later showed a 16mm hyperintensity.  I am just wondering what could cause these "hyperintensities" or "calcifications" that seem to come and go in my MRIs... I am at a loss my wish is to have a few names of possibilities that I can look up to either rule out or to keep as possibilities to ask a new doctor.  I have been so sick for so long that I just need to take control of my health and stop the run away train!
   Thanks for reading this and for sharing any thoughts
Vicky