Nice deflection.
Since you can't answer the question, the simple answer is, you just cant diagnose others and use that as a diagnosis for Sidney. Medical science isn't performed upon a forum. Sidney,(that's his name) has a history of injury which very much pertains to his actual health in healing. It's obvious to the doctors by his injury history that he is a slow healer from his past history or that they take their time in his recuperation. His history of concussions should be a cause for concern to his fan base.
Toews, Bergeron, etc, and their experiences with dealing with concussions have no bearing what so ever on Sidney. And to use that as an example is not only hilariously horrible and baseless to Sidney, but a weak and dangerously ignorant defense. Sidney has an obvious issue. The question should be what caused another concussion or if it's a lingering concussion from another occurrence.
Nobody knows, and the sad reality is, nobody will ever know the actual truth unless somebody can get a medical report which is impossible.
I actually feel sorry for Sidney. Brain trauma is a horrible thing to have and hard to completely over come. Medical clearance doesn't mean his brain is healed from trauma, it means doctors have cleared him to play. Which is why the extreme witch-hunt that's been triggered thru out sport concerning concussions.
Face it, nobody knows if Sidney isn't suffering effects still from his first concussion years ago. Only Sidney. That's the reality of actual brain trauma and dealing with the repercussions of it. And lastly, while I am not a doctor,
I have studied concussions and know a little bit about the subject. Sidney's voice pattern has changed subtlety in the last few years and I'll say it again, waking up with headaches isn't a good thing.
I would have to look at every instance of impact at every point he was concussed to look deeper into his situation, how much and where the damage was worse. Sidney gets a lot of flack for his play last year before the coaching change but it honestly could have been effect from concussions.