Post-concussion syndrome
Though no universally accepted definition of postconcussive syndrome exists, most of the literature defines the syndrome as the development of at least 3 of the following symptoms: headache, dizziness, fatigue, irritability, impaired memory and concentration, insomnia, and lowered tolerance for noise and light. One complication in diagnosis is that symptoms of PCS also occur in people who have no history of head injury, but who have other medical and psychological complaints. In one study 64% of people with TBI, 11% of those with brain injuries, and 7% of those with other injuries met the DSM-IV criteria for post-concussion syndrome. Many of these PCS sufferers were misdiagnosed as having other unrelated conditions due to commonality of symptoms. (see diagnosis, below).
Concussions in American football
With continued pressure to protect players, the NFL began preventing players knocked unconscious by a concussion from returning to a game or practice, a policy that applied to Detroit Lions running back Jahvid Best in . Various players have filed lawsuits against the league for the concussions, accusing the league of hiding information that linked head trauma to permanent brain damage, Alzheimer's disease, and dementia. Some teams chose not to draft certain players in the NFL Draft due to their past concussion history. According to an Outside the Lines report, the head impact telemetry system (HITS) was in question by the League, although Kevin Guskiewicz, a professor at the University of North Carolina, said the system is functional. The technology could detect and measure the impact of blows to the head in real time during a game, but no such measurement exists in the league at this time. Former Pittsburgh Steelers receiver and current NBC Sports analyst Hines Ward stated the use of the system would be "opening a Pandora's Box," and that the data recorded by the system could be used by team owners to give players lower salaries.