Doctors continue to differ on what role football-related head injuries played in the death of Terry Long 14 years after he left the game, and the NFL says it plans to begin a study within the year to determine the long-term effects of brain injuries.

Dr. Bennett Omalu, the neuropathologist who handled Long's case for the Allegheny County coroner's office, said yesterday he had a letter written by Dr. Joseph Maroon that noted Long suffered a concussion in 1987.

The letter said Long became light-headed, had difficulty concentrating and walked unsteadily after a collision with an opposing player, which led to a recommendation by Maroon that Long sit out at least a week. Omalu said those symptoms are consistent with "massive concussive injuries."

Maroon, the Steelers' team neurologist, said yesterday he "overlooked" the letter that was in the files after telling the Post-Gazette that Long never had a concussion on the football field. But Maroon added that he disagreed with the conclusion that it was a "massive" injury and that it was a stretch to link Long's death to football after so many years away from the game.

"That kind of injury is something that happens in the NFL on a weekly basis," said Maroon, an expert on concussions and a vice president of neuorsurgery at the University of Pittsburgh Medical Center. "Given Mr. Long's history of drug abuse and suicide attempts or whatever altercations may have contributed to his demise, I think it's just bad science to conclude that football caused his death."

The coroner's office concluded that Long, 45, died in June of a swelling of the lining of the brain caused, in part, by "repeated mild traumatic injury while playing football."

Omalu said that about 300 tests run on Long's brain tissue showed he suffered from a similar disorder as the late Mike Webster. That condition, chronic traumatic encephalopathy or pugilistica dementia, is most often seen in career boxers and is commonly known as being punch drunk.

Webster's family, alleging that Webster suffered football-related head injuries that led to his declining health, was awarded disability benefits earlier this year after suing the NFL pension fund.

If head injuries pose a health risk to football players, the NFL wants to address it and has established a committee on mild traumatic brain injury, which is chaired by Dr. Elliot Pellman.

While the coroner's office has called on the NFL to conduct a long-term study on head injuries, Pellman said plans for such a study were in the works. It will begin within the year and involve 160 active and retired NFL players, other athletes and those not involved in contact sports. That study would take two or three years to complete and will be published in a scientific journal.

"We owe our player/patients better answers," Pellman said.

But he also noted that to date, no one has been able to unmask the type of problems the coroner's office has detailed in its findings on Long and Webster.

"My problem is the conclusions are, from my end, speculative and unscientific," Pellman said.

Maroon, who has been with the Steelers since 1981, is co-founder of UPMC's Sports Medicine Concussion Program and helped develop a test to diagnose concussions that is used by the NFL, the NHL, NASCAR and a number of high schools.

"My job is to protect their brains," Maroon said.

He added that he had immense respect for Dr. Cyril Wecht, the county coroner. And Wecht, in reporting the findings on Long earlier this week, insisted that he wasn't trying to be critical of anyone while he called attention to what he saw as a medical problem.