乌鸦传媒

Athletes who play contact sports for long periods may be at greater risk of developing Lewy body disease, a neuropathology study suggests.

People who played football, ice hockey, boxing, or other contact sports for more than 8 years were over six times more likely to develop neocortical Lewy body disease -- and in turn, symptoms of Parkinson's disease and dementia -- than people who played for 8 years or less, reported Thor Stein, MD, PhD, of the Boston University School of Medicine and colleagues in .

"Other studies have shown that a single traumatic brain injury is associated with an increased risk of developing Parkinson's symptoms and Lewy body disease in the brain at pathology," said Stein. "Our study looks at this in the context of contact sports play, looking at many years of repetitive concussive and sub-concussive hits."

While Lewy bodies can affect a number of different brain areas, "we were specifically interested in looking at the cortex because we think that's where a lot of the injury occurs," he told 乌鸦传媒.

He and his colleagues studied 269 brains from deceased former athletes and 164 brains from Framingham Heart Study participants, representing the general population.

In a pooled analysis, a threshold of more than 8 years of play best predicted neocortical Lewy body disease (OR 6.24; P=0.011), adjusting for age, sex, and apolipoprotein E (APOE) ε4 allele status. People with both chronic traumatic encephalopathy (CTE) and Lewy body disease were significantly more likely to have dementia and symptoms of Parkinson's disease than those with CTE pathology alone.

Since CTE was first described in the 1920s, scientists have hypothesized that the tremors, slowness, and gait problems that appear in CTE cases were caused by CTE pathology, Stein noted.

"We were a little surprised: going in, we thought some of these motor symptoms would be explained by CTE. But when we did a separate analysis to look at the associations between pathologies and the development of Parkinson's symptoms, we found CTE pathology was not correlated with that, but Lewy body disease pathology was."

The brains in the athlete group do not represent all people who play contact sports or sustain repetitive head injuries, the researchers noted; the brains were mostly self-selected or referred by next of kin after death.