Los Angeles (CNN) -- About a year ago, a former quarterback with the San Diego Chargers and a retired linebacker with the Minnesota Vikings lifted their once-sturdy frames onto a cold examination table. Meanwhile, a radioactive chemical was coursing through their bodies on its way to receptors in their brain tissue. A hum filled the room as each man slid toward a doughnut-shaped opening on a brain scanner. When their scans were later analyzed, crimson and bright yellow bands appeared deep in their brains, indicating damage. The two former players, Wayne Clark and Fred McNeill, were participants in a pilot study at UCLA that may have found a destructive protein called tau in the brains of five living retired National Football League players.
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Former NFL players Wayne Clark and Fred McNeill participated in a UCLA study
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The protein tau, linked to a brain disease, was found in both of their brains
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McNeill has early-stage dementia; Clark does not
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Researchers say other variables may come into play when it comes to the disease
She knows that story well, recalling McNeill's roommate when he played for the @placeholder.