(CBS/AP) - Seventy-five former players are suing the National Football League, claiming the league concealed information about the danger of concussions for decades.
The negligence and liability suit filed Tuesday in Los Angeles Superior Court lists Raymond Clayborn, Ottis Anderson and Mark Duper as plaintiffs, among others. Most players listed their wives as co-plaintiffs.
Helmet maker Riddell also is a defendant.
The suit alleges the NFL knew as early as the 1920s of the harmful effects of concussions and claims that information was concealed from coaches, trainers, players and the public until June 2010.
NFL spokesman Greg Aiello says the league hasn't seen the suit but would "vigorously" contest any claims of that kind.
"The suit claims the NFL commissioned a study in 1994, titled 'NFL Committee on Mild Traumatic Brain Injury' and published a report in 2004, concluding there was 'no evidence of worsening injury or chronic cumulative effects' from multiple concussions.
"And, the suit alleges, it was not until June 2010, that the NFL acknowledged concussions can lead to dementia, memory loss, CTE and related symptoms. All of the players are claim[ing] they suffered injuries as a result of multiple concussions."
The news comes the same week that a new study revealed that retired football players are at heightened risk for mild cognitive impairment (MCI), a subtle form of dementia that is considered a prelude to Alzheimer's disease.
The study is follow-up work on nearly 4,000 retired National Football League players surveyed in 2001. New surveys were sent in 2008 to 905 of them who were over 50. Of those who responded, 513 had spouses who could complete the part assessing the players' memory.
"We were surprised that 35 percent of them appeared to have significant cognitive problems," said lead researcher Dr. Christopher Randolph of Loyola University Medical Center in Chicago.
As CBSSports.com's Josh Katzowitz notes, the NFL Alumni group has been making its views widely known recently about concussions, and they obviously haven't had a great relationship with the NFLPA. So, instead of sitting down at negotiations between the two sides in the lockout (where they seemingly have been marginalized), some former players are instead looking to the legal system for justice.