Sorry about your injury!
I get really interested when I hear of your colllapses since I have experienced similar things myself.

What happens is that when I exert myself to much, from having a long conversation or things that takes a lot of concentration, I get shaky and dizzy. The brain cant keep up with the metabolic demands it seems like. If I take short breakes I spare more energy and I have less of these incidents.

I use to think of it as when streaming a movie online. If you try to watch it while it hasnt downloaded enough it lags and get stuck and doesnt play smoothly. '
If you pause it for just a little while and let the buffer build up you will be able to watch the whole thing smoothly. I believe this is exactly what happens in the braincells. Probably it is a combination malfunction including energy-conversion (ATP production which is a cells energysubstrat) and transmittorsubstance production.

The cause for this "malfunction" can be either damage to single cells or as for the most PCS-patients with diffuse-axonal-damage due to tear and shear loss of axons. This means that other neurons have to take over for the lost ones which axons has been damaged. These "compensatory" neurons have more job to do than regular and therefor get more fatigued! This is MY hypotesis of the less severe PCS. NOT PROVEN


I have one comment to Mark also. I am a medical student in the beginning (2nd year) of my education and have just had 5 months of neuro physiology. (We have more of that here in Sweden than other medical educations around).

When I read your comments I see all your experience and trial and error info etc which is THE MOST IMPORTANT thing for people here to learn. Keep posting that stuff!!You help tons of people!
What sometimes (but absolutly not always) is lacking is correct medical info. People CAN get confused and learn the wrong info which they than see as the thruth and tell their doctors, believe in etc.

For an example: You said that its during REM-sleep you "recover" and regain your energy. This is not true. During the REM you have almost awake activity in your brain. (Therefor the motorneurons get inhibited so you dont run and move in your sleep). In deep-sleep its the opposit. I asked my doctor if there is any way to get more of the deep sleep and less of the REM. With farmacological ways that is. He didnt know anything about it.

Since many people that use "antiepileptica" and other drugs that reduced the activity in your brain in generel have positive effects on the fatigue my hypotesis could be correct.

HOWEVER if you could mixture with the sleep and have only deep-sleep you would have severe problems with establishing new memory which is one of the things happening during REM-sleep!

People try to cure themselves (I do it myself!) by searching online and reading medical reports etc. This is good in a way but bad in another.

If you really want to learn how the brain and nervous system works you better get yourself a neuroscience book instead of spending the time reading online.

Many medications seem great but what is NOT sure is its safety. The mileu in the brain is SO complex. Adding a drug that fixes one thing CAN have effects on cellsignaling, metabolism, toxicity, and other things.

Some random info from me...my brain is now tired and I shall quit writing!

Emil