From AAT cases it appears that if you have EVER lost consciousness as a result of a concussion or similar trauma you will NEVER get a medical certificate again ever.
Wrong!!!! I know of two airline pilots who are still flying who have been concussed from head trauma. Very similar process to cardiac problems. You lose your medical for a period of time while your condition is monitored, months not years. If there are no continuing issues then you get to go flying again.