It isn't surprising to me that this remains the most popular post of all time here at Redwood's Medical Edge with nearly 1000 page views. This myth continues to be perpetuated in books and TV.
I love the series Dexter. If you're unfamiliar with it and you're a writer, I think it's a great exercise in intricate plotting techniques. However, it is violent, so proceed with caution. The general premise is that Dexter works for Miami Police as a blood splatter specialist. In his free time, he's a serial killer, but only kills those that the justice system doesn't put away. This show is also good study for the sympathetic villain.
In one episode, poor Dexter has been in a motor vehicle collision. He is dazed and is taken to the ER. The doctor says something to the effect of, "You have a head injury. You'll need to stay awake for the next several hours." Great.
Sleepiness post head injury is a classic set-up for pediatrics. Every day in the ER is a story like this. It's close to bed time. The children are running amok. Some child falls down, falls into, or falls off of something and hits their head. They cry their little heart out. After all, hitting your head hurts, a lot. After a good crying bout, they're sleepy. Parents first thought is, he must have a terrible head injury. Off to the ER.
Now, one, I want to make it clear. Getting your child checked in the ER for head injury is good and reasonable. However, we aren't all that concerned with sleepiness. What we are concerned with is how arousable they are from sleep. This is what we'll be monitoring every fifteen minutes to an hour if the child sleeps during his ED visit.
Level of consciousness is assessed as an indicator of an injury going on inside of the head. How arousable you are is the most sensitive indicator of level of consciousness. If the child falls asleep, and we are concerned about head injury, we'll try to wake them up every so often to assess their level of arousability. If we cannot wake them up, then we are concerned. It has to be more than a gentle nudge. You are really working to wake the patient and they won't respond. This is concerning.
Remember, things that are injured need rest. This is why we put you on crutches if you break an ankle. The brain rests by sleeping. It helps it to heal. If you're a subscriber to this myth, how long should we keep the patient awake? An hour? Two hours? A day? If you want a skewed neuro exam, try doing one on a sleep deprived patient.
For additional resources regarding this myth, check out the following: