I yawn sometimes for 8 to ten minutes with 13 to 18 seconds between yawns. My eyes water and get pains in them too.
When I look after brain injured pts generally traumatic they never stop yawning. I do too since my surgery and don't think I'm tired. its getting more oxygen to the lungs and that keeps the heart working to keep brain oxygenated. Just talking about it is making me yawn now LOL
I often get bouts of constant yawning when my stress levels are high? Not sure why, I just know its stress/anxiety triggered
It depends on the meds you are taking and what are your supplements. Also if there is any caffeine in your diet. Caffeine causes triggers which can lead to seizures.
I know yawning can be a precursor to amigraine.