Brain Injury Basics: What You Need to Know

March 27, 2009 — -- The recent death of actress Natasha Richardson from a ski accident has many people asking questions about head injuries, and why some can end up producing no more than a bump on the head while others can kill.

Read more: Female athletes suffer from concussions more often than their male peers.

What are the signs you may have a concussion?

The chief warning signs are confusion, memory loss, headache, nausea or vomiting, blurred vision, slurred speech and balance problems. All of these symptoms do not have to be present, and they can range from mild to severe.

What should you do if you think you have had a brain injury?

If you have lost consciousness from a head injury, seek immediate evaluation at an emergency department. Do not drive yourself to the hospital. The same applies to other serious symptoms such as blurred vision, slurred speech or severe headache. For mild head injuries, be sure to watch the victim closely for 24 hours for symptoms that might develop. If the victim develops any symptoms of concussion, seek medical attention right away.

Dr. Jam Ghajar, a neurosurgeon and president of the Brain Trauma Foundation, answers more questions about brain injuries.

How common is it for what seems like a simple bump on the head to become fatal?

About 1.7 million people each year visit emergency rooms with head injuries, and 90 percent turn out to be concussions. Of those people, about 80 percent recover from the concussion within three months.

The symptoms of a concussion include headache, attention and memory problems. All functions are working, they just seem to be out of sync -- it's really a timing problem. The brain can essentially get whiplash, forming tiny tears in the front of the brain, in the area that controls timing.

About 20 percent of people go on to have problems that include but are not limited to fatigue, irritability and severe headaches. Only a fraction of people die as a result of a traumatic brain injury.

How soon after a head injury can you tell whether you're looking at a mild concussion or something life-threatening?

I get a lot of calls from moms who say, "My kid hit his head. Should I go to the emergency room?" And since kids don't express themselves well, you really have to pay attention to how they're acting.

Is the kid acting normally? If so, and they continue to, it's probably OK. If they are awake, and this is true at all ages, that's a good sign, but make sure they can pay attention. Ask them questions, ask them to follow your finger.

They may be walking around, and they may look OK, but in these serious injuries, what's been affected is the frontal lobe. That doesn't control how you look, it controls your executive processes -- your ability to focus, to understand what's being said to you, to make decisions. So that's what you're looking for.

If someone is vomiting, if there's a seizure, a loss of consciousness or blood coming out of the head, you want to go straight to the ER. If they're feeling suddenly sleepy, go to the ER. Kids can also act squirmy, moody and slur their speech.

Eye dilation is a sign someone is going into a coma. There's a brain bleed that's constricting those vessels.