"Knocked Senseless: Concussions have upsetting impact on NFL". 
Bruscas, A. (November 7, 2000) Seattle Post - Intelligencer.

The focus of this newspaper article was to provide some anecdotal accounts of football players who have sustained concussions as "part of the game". While many players downplay the effects of having a concussion, there are many lingering symptoms that follow the initial hit. Such symptoms include, but are not limited to, headaches, dizziness, anxiety, depression, poor attention, memory loss, and irritability. Some players have reported some loss of memory prior to as well as following the concussion. In particular, Brock Huard, a Seattle Seahawk, recalls that after being hit during the game against the Oakland Raiders in November 2000, he was calling teammates and training staff by the wrong names, was unable to remember the plays, and could not feel his hands.

Still, many players, coaches, team doctors, fans, and so on tend to underestimate the cumulative effects of small, apparently innocuous concussions. While most of the football players who receive concussions are quarterbacks, other players are not immune. In fact, it has been reported that at least 100,000 football related concussions are reported nationwide each year. The American Academy of Neurology reported that around 60% of football players acknowledged experiencing at least one concussion in their career while over a quarter of all football players have had at least three concussions. Even more alarming, football players with a history of brain injury are reportedly six times more likely to suffer a more serious concussion.

There is ongoing debate as to whether players who have sustained multiple concussions should be allowed to return to play the game. However, common perceptions have changed so that a more conservative and cautious approach is being taken, as it becomes more evident that the cumulative effect of several concussions can cause significant and often permanent brain damage. To this end the NFL has become more active in educating people about concussions and redefining the criteria for what a concussion is and when it needs to be reported. Unfortunately, there are still cases where players and coaching staff may either fail to report or discount the effects of concussions so that players can return to the game.

While concussions are quite common in football, they also occur in other sports, such as boxing, hockey, soccer (i.e., heading the ball). In addition, many athletes experience their first concussion in high school. Thus, while there is ongoing research to more fully determine how concussions can effect long-term brain functioning, efforts also need to be put towards educating young athletes and their parents, teachers, and coaches about concussions and brain injury

Jennifer L. McCain, Psy.D. 
Neuropsychologst, 
The Brady Institute for Traumatic Brain Injury and Coma Recovery