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).
Andre Waters
Shortly after Waters' death, former Harvard defensive tackle and WWE wrestler Christopher Nowinski, whose wrestling career was ended by post-concussion syndrome and has since written a book about the dangers of concussions in contact sports, approached Waters' family and asked permission to have his brain tissue examined. After receiving permission, Nowinski had samples of Waters' brain tissue sent to neuropathologist Dr. Bennet Omalu at the University of Pittsburgh. Omalu believed, having examined the tissue, that Waters sustained brain damage from playing football: he went on to state that this led to Waters' depression. Omalu determined that Waters' brain tissue had developed chronic traumatic encephalopathy (CTE) and degenerated into that of an 80-year-old man with Alzheimer's disease, caused or hastened by the numerous concussions Waters sustained playing football.