Hi Canadoc! I'm not a doctor, but I do play one when I diagnose myself on the Internets

Are you sure your intolerance to weightlifting isn't just the plain old symptom exacerbation many of us experience with high heart rates? You mentioned you were able to get back to sport without inducing headaches, but did you/do you go to the point of very high heart rate or anaerobic exertion? Maybe you can tolerate a certain heart rate but not higher and lifting sends that heart rate spike/ pressure up.

I haven't posted here yet, just lurked since my concussion November 2013 but the way you describe your post-lifting mental state is VERY similar to what happens to me when I tried to exercise and get my heart rate up. I was healing, slowly, from my original accident and actually got to the point at two months where I felt basically no symptoms at rest but if I tried to exercise I got a brain fog feeling, blurry vision, dizziness, etc. Depending on how much I did, it would last half a day or a day or so.

Then two weeks ago I lightly tapped my forehead into a small tree. I know, it sounds bad, but it was honestly lighter than the taps we've already probably done pre-PCS, like hitting into a car door or something. It didn't even hurt. But I'm still in a mild relapse of symptoms. I refuse to consider it a rein jury because that's just way too depressing and I'm not nowhere as bad as I was after my original concussion. I'm choosing to think of it as a setback in my healing.

I go to U of Buffalo this Monday to see Dr. Leddy and his team. Before my tree tap setback I had started their protocol on my own and was progressing nicely, from twenty minutes at a heart rate of 120s up to 140s over three weeks, with no return of symptoms. Stupid tree!

Anyway, just out of curiosity, what would happen if you slowly monitored your heart rate until you go to your max heart rate...would any of those same symptoms that happen after lifting/ exertion come back? Might be worth your time to try it out.

Good luck!!