[wswope]

I suspect the person you're responding to was just throwing that out carotid dissection as an example; the general risk factor with BJJ is vessel wall injury (which dissection is a subset of). Blood clots from vessel trauma in peripheral parts of the body can migrate to cause thrombosis elsewhere.

Chokes are a big cause of vessel trauma, but hard takedowns, pressure passes, accidental strikes from spazzy white-belts, etc. all count too. Anything that can cause major bruising, really.

To be clear, I'm not trying to argue that anyone should avoid BJJ due to cardiovascular risk, and the sport is probably a large net benefit to cardiovascular health on the whole - but it can certainly be a proximate cause of a stroke if you get unlucky.

[stouset]

Interesting, I hadn't heard about the bit about clots from vessel trauma in peripheral areas.

Thankfully I'm getting my PFO closed in two weeks. The left and right sides of the heart should be isolated systems, and a PFO is a hole that potentially allows a clot to travel from the body side to the brain side. Hopefully if this was related to that, closing the hole will prevent such a thing from happening in the future. Apparently if the hole is closed, a clot would likely travel to the lungs, which are significantly better at coping with it than the brain is.