I always learned that if someone got “dinged” that he should be kept awake.
How long should someone be observed after receiving a mild brain injury and is there a time frame for the person to stay awake?
There is no benefit to keeping someone awake after a concussion, and it is no longer recommended. In fact, people with a concussion need to sleep to recover. In the days before head CT scanning was widely available, the only way to know if someone had life-threatening brain bleeding (which occurs in less than 0.1 percent of those with concussion) was to observe him for a decrease in his level of alertness that resulted from the blood pressing on vital brain structures. This usually happened within six hours of injury. It was thought that if you could keep someone awake you could prevent him from lapsing into coma, which of course did not work.
Anyone getting very sleepy within six hours of a brain injury should be brought immediately to an emergency department for a head CT scan.