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).
Harry Carson
While Carson has acknowledged he has "managed" the long term effects of concussions he does not know if he has been affected by chronic traumatic encephalopathy (CTE). When asked, Carson is increasingly critical of the NFL and questions whether football should be played, as he believes the hazards of concussions and subconcussive hits are not an understood risk such as physical ailments are. He is quoted in this interview as saying of the NFL's $765 million settlement with former players that "the NFL has given everybody 765 million reasons why you don't want to play football."