Why doctors tread carefully when it comes to concussions

When doctors took a few days to conclude this week that Seattle Seahawks running back Shaun Alexander had recovered enough from a concussion to play in this Sunday's NFC championship game, they weren't being overly cautious.

If Alexander hasn't fully recovered, a second concussion could leave him with lifelong disabilities, including problems with memory, reasoning, speech, vision, hearing or movement. Or even kill him.

So as doctors do with all concussion patients, the Seahawks physicians went on brain watch: They checked his memory and decision-making, his balance and movement, and other factors to assess how his brain fared when a knee hit his helmet during last Saturday's game against the Washington Redskins.

Then they observed whether all those factors still held together when he exercised.

"You look for whether the [patient] can go back to what they were doing before" the injury, said Dr. Richard Ellenbogen, chief of neurosurgery at Harborview Medical Center and a consultant to Seahawks physicians.

Traumatic brain injuries are a major public-health problem. Nationwide, 1.4 million people a year receive them. About 75 percent of those injuries are concussions.

And repeated concussions have ended the careers of some of the country's top athletes, including quarterbacks Steve Young of the San Francisco 49ers and Troy Aikman of the Dallas Cowboys.

Some 50,000 people a year die of brain injuries, and about 90,000 others have long-term disabilities, according to the Centers for Disease Control and Prevention.

A concussion is generally considered the most minor form of brain injury. Technically, it occurs when someone loses consciousness, however briefly, after a blow to the head. But experts also consider it to be any temporary loss of awareness.

Athletes and coaches simply call it "getting your bell rung."

Sports of all kinds lead to about 300,000 mild to moderate brain injuries a year. But the biggest cause — with more than 700,000 cases — is accidents involving autos, motorcycles, bicycles or pedestrians. Falls and violence such as assaults cause most of the rest.

Experts say the riskiest sports for head injuries are football, boxing and ice hockey, though other sports such as soccer, rugby, gymnastics and skiing also pose risks. Helmets are the most recommended protection.

No one knows exactly what happens in a concussion, when the brain, which is normally suspended inside fluid, hits the side of the skull. But many experts believe that the basic chemistry of the brain is disturbed: Neurotransmitters, substances that convey impulses between brain cells, are jostled.

"It is an extraordinarily complex and precise system," said Dr. John O'Kane, University of Washington team physician. "If there is a [jarring] it makes it more fragile."

So physicians emphasize that receiving a second blow to the head before fully recovering from the first concussion is very dangerous.

People younger than 20 are most at risk for a relatively uncommon complication of concussions called "second-impact syndrome," in which even a relatively minor bump to the head can set off devastating, sometimes fatal, swelling of the brain.

Alexander is 28. But for anyone, a second brain trauma increases the risk of blood clots or other damage that can cause permanent disability, O'Kane and Ellenbogen of Harborview warn.

One recent study of about 2,900 college football players suggested that those who suffered a concussion at any time are more likely to have future concussions than those who have not had any. Players who had previous concussions may recover more slowly, the researchers concluded.

Typically, a person with a concussion won't remember the blow, or events just before and after. Some symptoms may take days or even weeks to appear.

Generally, the longer someone is unconscious or continues to have other symptoms, the greater the risk of a more serious second injury with lingering complications, Ellenbogen said.

In the National Football League, all players are given a cognitive test at the beginning of each season. Then, if they receive a concussion and symptoms linger, they are given the test again, even after there are no outward signs of injury, to see whether there are any subtle deficiencies. High schools and colleges also sometimes use such tests.

Concussion patients are told to get plenty of rest, both physically and mentally, to allow the brain to recover. Often that even means avoiding reading and watching television.

"A concussion is an injury to the brain," O'Kane said.

"And if the brain is not working, nothing else really matters."

Warren King: 206-464-2247 or wking@seattletimes.com