I've had these several times myself. For me, they start as a small "blind spot" at the center of my field of view, which was really scary, particularly if I was trying to read or do screen-work at the time. After the first one, the appearance of the rainbow zig-zags was actually comforting, because that confirmed what it was. Since I was effectively incapacitated for the duration, I'd just lie down and enjoy the light show.

It's been years since I had an occurrence, but the timing was pretty reliable.

~30 minutes: slowly growing blind spot at the center of my field of vision.

~15 minutes: rainbow zig-zags in a slowly expanding circle from the blind spot until it encircled my whole field of view, after which it faded out and I could focus pretty normally again. No headache during or after.

After multiple rounds, I figured out the, or a, trigger: absinthe. Drinking absinthe reliably brought one on ~18 hours later. Only ever had one that I couldn't tie to absinthe. Stopped drinking absinthe years ago, and the scintillating scotoma stopped as well.

Sounds about right, good to rule out any sort of stroke… Though honestly that pulsating phase the article highlights was the least of my problems. For 10 minutes or so while it’s there you can at least tell something’s wrong, for the rest of the day it’s a treacherous blind spot that’s easy to forget about.