Proof, if proof were needed, of why this is so serious an issue.
Berrick Barnes' career looks like it could well be over, due to his history of concussions and what would seem to be linked migraines, amnesia and nausea.
Barnes himself has been running a campaign for heavier padding in scrum-caps; unfortunately, the evidence so far is that they don't have any effect.
The lesson is clear; at all levels, the game needs proper assessment, proper treatment, and, on the pitch, and end to the idea that anything above the line of the shoulders can be shrugged off as "There was nothing in that". It's too risky, and we can see why.
And, again, one has to ask - why has it taken so long for so many unions, and the IRB, to introduce proper concussion management procedures when the evidence has been there since 2007 that using SCAT cards works?
H/T to Green & Gold Rugby for highlighting this one.
Update; unfortunately - but probably wisely - it seems to have moved from "Berrick Barnes career could well be over" to "probably is" - he's now on an indefinite break from the game.