Head Injuries Can Be Fatal, Even Without Immediate Symptoms

After a serious accident, victims often experience overt pain or immobility that leads them to seek immediate medical attention. But what if you injure your head and feel okay afterward? What should you do?

Actress Natasha Richardson, who was critically injured Monday after she fell during a private skiing lesson, reportedly did not show any apparent sign of injury, and she even walked after the incident. It wasn't until about an hour later that she reportedly complained of an extreme headache and was taken to a hospital. (UPDATE 5:16 PM: Natasha Richardson has died from the brain injury she sustained during a skiing accident. Our thoughts are with her family.) 

When you experience serious trauma to your head, you can be at risk, even if you feel fine and have no symptoms, says James J. McCarthy, M.D., assistant professor of emergency medicine at University of Texas Medical School at Houston.

"You've got confined space inside the skull, and blood from the injured blood vessels flows into the same space that the brain occupies," says McCarthy. "This growing clot of blood starts taking up more and more space, and puts pressure on and decreases the flow of oxygen to the brain." The brain can literally be squeezed to death, he says.

McCarthy says you may not have symptoms until you get a headache, which can be a sign of ongoing hemorrhage or bleeding around the brain. "This pressure [that's] built up makes the head hurt," he says. However, you can be free of symptoms for some time. McCarthy has seen people with head injuries who came to the hospital four or five days after their initial incident. In those cases, the clot inside the skull grew slowly, and pressure on the brain built up gradually.

If the injury to a blood vessel or vessels is small and your body's blood-clotting ability is normal, the bleeding may stop, says McCarthy. This would likely prevent a larger clot from forming, and pressure from building up. For more serious bleeding, surgery is often required to alleviate pressure on the brain, he says. People who are on blood thinning medication, such as Plavix, are also more at risk, because it's more difficult to stop the bleeding resulting from the trauma.

After head trauma, when do you need to seek medical care?

McCarthy advises getting evaluated at a hospital, if you become unconscious even briefly as a result of a head injury and even if you feel fine afterward. "Going unconscious raises your risk significantly," he says. If you feel fine, then watch for symptoms (or have a companion watch for signs), such as headaches, weakness or balance problems. If you experience these symptoms, seek medical attention immediately. 

You also need to be medically evaluated if you experience nausea or vomiting, says Jeff Kalina, M.D., associate medical director of emergency medicine at The Methodist Hospital in Houston. Pressure on the brain stimulates the vomit reflex, he says. And while a torn artery inside the head will cause the blood clot to form quickly, says Kalina, injuries to smaller blood vessels mean the clot may take longer to create pressure on the brain, potentially leaving the person symptom-free for a longer time. 

People older than 65 also may not show symptoms for a length of time, says Kalina. With these conditions, the brain is likely to have atrophied somewhat, which means less space is taken up in the skull. It therefore takes a longer time for collected blood to exert pressure around the brain, he says.

To help protect your head from trauma, wear a helmet when participating in sports, or when you're exposed to traffic while riding a bicycle, says McCarthy. Reports noted that Natasha Richardson was not wearing a helmet during her accident.

"The likelihood of a serious problem is very small if, after a head trauma, you've got no external signs of injury and you feel okay," says McCarthy. "But your risk is never zero."

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