I know it has been a little while since @landers2189 ask but I thought I might add a little. During grad school, I worked as a research assistant for one of the leading researchers for concussion.
Pete is spot on that concussion can affect multiple different systems. It can also lead to some autonomic dysregulation. Which can cause some funky symptoms. A few questions I had are as follows:
1) How long ago was the concussion?
2) When your friend crosses 8,000 ft and starts getting lightheaded, is it after exertion or just merely being above 8,000ft?
3)When they experience these symptoms, what is the pattern that they experience them? If they were to rest do they get better, stay the same, or get worse?
4)What kind of fitness do they have? Do you know approximate aerobic and anaerobic threshold? Do they do any training in Zone 4 or 5 and what is there response to that?
So you know why I asked some of these questions. For #2, this would help understand if it’s exertion based or just purely altitude. If it’s just altitude, they could almost do what would look like acclimatization at a lower elevation. Questions #3 indicates how much they could lean into symptoms (usually for long-standing issues you need to lean into symptoms a little). For #4 high levels of exertion can trigger symptoms but, if your friend has a high level of aerobic fitness then it may take quite a bit of intensity to get to that point. Thus the altitude challenges the physiology to that higher level.
There are lots of directions that this could go. Hopefully, this was helpful and not too overwhelming.
Also Pete as an FYI, JOSPT just released a new CPG for concussion.
Hope everyone is having a great Easter and staying healthy!
Dan Crusoe, PT, DPT, OCS, CSCS