Please remember that I am not a well informed or educated person but I've recently been a bit through the mill with "lesion" and MRIs,
I developed terrible headaches in the late 80s' and started having what I called "spells" but doctors ignored my complaints.
A grand mal seizure in 1990 brought on my first MRI ........
Oh - this story is too long.

I've continued having migraines (taking all the triptans), having seizures (complex partials) and another MRI in 2005 showed a lesion (tumor) that was removed Feb., 2006.

I have had more MRI every three months since then, PET scans, neuro psych testing, yadda yadda. No doctor has ever said anything about a migraine or any headache causing a lesion or having anything at all to do with one. They have said it's possible my tumor was there at birth.