I think its the same with all people interested in kiteing or similar sports.
Point in question, I recently stacked it off my Freebord (bought from SOS, shouldve been a kite) and smacked my noggin on the road. Just thought it was a concussion or a headache and went for another ride or two, then went home feeling dizzy and went to bed after a few hours. Woke up and got shipped off to hospital with a blood clot on my occipital lobe.