By Paul Burton, WBZ-TVBy Paul Burton

BOSTON (CBS) – A new study shows concussions, head to head collisions and even mild hits to the head on a continuous basis could lead to a fatal degenerative brain disease called Chronic Traumatic Encephalopathy.

“It starts with a whole bunch of hits, but it sets in motion the disease that gets worse and worse as someone gets older,” Dr. Robert Stern of BU School of Medicine said.

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Dr. Stern was part of a four year study of 85 brains of deceased athletes who had a history of repeated mild traumatic brain injuries.

Dr. Stern says 68 of them had CTE.

“It involves the progressive deterioration of brain cells and leading to death of brain tissues,” Dr. Stern said.

Patrick O’Halloran of Burlington suffered a severe concussion and brain injury when he was drilled in the head with a baseball back in August. Today he is doing much better, but his mother is concerned about whether her son should be playing anymore contact sports.

“Some doctors say he shouldn’t play and others say he should limit it just to one,” Denise O’Halloran said.

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Dr. Peter Warinner is the Director of Sports Neurology at Brigham and Women’s and Newton Wellesley Hospital. He says the CTE study while informative is not conclusive.

“There could be other causative factors and not just head trauma. There could be genetic factors and people may be destined to get this even if they had head trauma or not,” Dr. Warinner said.

As for 13-year-old Patrick O’Halloran, he just wants to play football, hockey and baseball again.

“Doctors say I should drop out of my contact sports or just limit it to one. I am disappointed because I want to play my sports,” Patrick said as he tossed the football to his younger brother outside his home.

Dr. Stern says parents should not panic.

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“Doctors and scientist should not interpret this as meaning anyone with a history of hitting their head is going to get this disease. But the flip side is real true. To get this disease you need to have a history of repetitive brain trauma,” Dr. Stern said.

Paul Burton