Hello Martin,
No advice from me, only to say I've had "scintillating scotoma" on 4 or so occasions in the last 5 years. They appeared without any known reason or trigger. They last for 30mins, and 2 of the 4 times, I've been rewarded with a nasty headache for the rest of the day.
I have no other problems I'm aware of. The 1st time this happened I went to the ED (which was 100m from work... walked in). There was no comments, or offers for further consultation. Simply, "Take these, expect a headache in 1 hour, and drop back in if it happens again". As promised, the headach happened, and I haven't been back.
It was a strange relief to see the example images showing just what I was seeing. It's weird, and somewhat unnappreciated being blind in one eye for 30mins.
https://www.google.com/search?&q=scintillating+scotoma