In what might be called a head-to-head comparison, a new study partially based in Pittsburgh finds that National Football League players recover faster from concussions than do high school players.

The study, which is being published in the February issue of the journal Neurosurgery, found that NFL players usually returned to normal performance within one week and most of them were performing normally within two days after a concussion.

But many of the high school players in the study -- many of them from Western Pennsylvania -- weren't back to normal a week after injury. In fact, about one in five high school players still had problems three or four weeks after their concussion, said Mark Lovell, a co-author and director of the UPMC Sports Medicine Concussion Program.

The study was led by Dr. Elliott Pellman, team doctor for the New York Jets and chairman of the NFL's Committee on Mild Traumatic Brain Injury. It included 68 NFL players and 125 high school players, all of whom were evaluated using a computerized neurocognitive testing tool, called ImPACT, developed by Dr. Lovell and colleagues at the University of Pittsburgh.

The slower recovery for young players isn't surprising, said Dr. Lovell, director of neuropsychological testing, but it underscores the need to develop new guidelines for concussion treatment that take age into account.

"We're not born with a brain in an adult state," he explained, with neurological development taking place into a person's early 20s. The developing brain likely is more vulnerable to injury than is the brain of an adult.

But the results also may be skewed a bit by the process of natural selection that occurs before players join the NFL. People who are vulnerable to concussions -- those who in boxing parlance would be said to have "a glass jaw" -- tend to drop out of football at the college, high school or even earlier levels, Dr. Lovell noted.

"Who goes to the NFL? Generally, these are guys who usually don't get hurt easily," he said. "Whether it's a knee, a thigh, or a brain, this is physiologically a hardy group."

Concussions occur when a blow to the head or upper body jolts the brain inside the skull. In some instances, a concussed player may lose consciousness; in more cases, they may suffer some combination of dizziness, headache, confusion, nausea and amnesia.

The ImPACT tool helps assess memory, reaction time and other neurocognitive factors. Scores on the test battery after an injury can be compared with pre-injury scores to help assess the degree of injury and progress in recovery. It is used throughout the NFL and many other professional sports leagues and is used by more than 1,000 high school football teams, including most of those in the Pittsburgh area.