Never heard of this before. An internet search turned it up under "white spots in the brain."
If you tend to "catastrophize" (Catastrophizing is an irrational thought a lot of us have in believing that something is far worse than it actually is---internet), I would avoid trying to diagnose this via the internet.
Apparently, this can be simply a sign of an internal issue that your body has resolved, or be a sign of a more serious condition---and the problem is that "differential diagnosis" is somewhat difficult.
Best of luck