I got PCS from Thai boxing (muay thai) sparring. I don't understand how someone like my coach, who started fighting when he was 7-8 years old in THailand, does not have PCS after nearly 250 fights where the blows are much much harder than the sparring blows I sustained.

Or someone like Sidney Crosby who had serious PCS from seemingly innocuous hits but Jaromir Jagr can take a head hit from Ovechkin in the Olympics and not get PCS.

Why such different in response?

I think some people just have a genetic disposition of more easily getting concussion symptoms. The neck can also absorb a lot of the force. It depends on the type of blow as well, not just the magnitude of the force.

That is what I was told by my neuro.

Not sure there is really an answer other then we are all genetically and physically different, and each insult the the brain is different.

Why did Muhammad Ali develop Parkinson's when Tyson and others haven't?

Yea life is not fair

Five years ago, I did Western boxing for a few months and remember getting hit MUCH harder during sparring and none of this concussion thing ever happened.

Brain injuries are a result of a combination of physiological genetics, hormone systems, and blood and other chemistries complicated by the myriad of different forces of each impact. Any one can be weak making injury more likely. Plus, as said before, the brain is extremely complex and each injury effects different parts of this complexity.

There are many people who have appeared to endure many head impacts with minimal noticeable injury then one final impact and everything changes.

There is also a big difference between how different individuals relate to their symptoms. Those with higher intellectual skills notice more struggles. Those with higher levels of coordination and balance notice more losses in these areas.

Sydney Crosby had thousands of hits before his life changing hit. They all add up.

Hi Mark! Good to hear from ya again.

It seems that Sidney Crosby has sort of healed though. Even the puck to the jaw didn't bring back the concussions.

The puck to the jaw without a big return of symptoms does not mean anything. He could get a simple body check and have his concussion symptoms come flooding back.

There is a hard and fast rule. Do not compare different concussions nor those who suffer from them. Everyone is different.