Effects of Repeated Concussions
And the dangers of them.
Kevin Guskiewicz and his colleagues from across the United States sought to research the effects of successive concussions. They published their study in 2003, detailing the cumulative effects of concussion among college-age football players. Guskiewicz and his team contacted 36 National Collegiate Athletic Association (NCAA) schools. 29 school athletic trainers responded. Gusikiewicz and his team eliminated 4 schools because of a lack of data. 19 of the schools were Division I, 3 were Division II, and 3 were Division III.
Guskiewicz followed 2905 players participating in college football over 3 years (between 1999 and 2001). They evaluated the players using the Graded Symptom Checklist (GSC) and a long health survey. Guskiewicz and his team used this information to create a database of background information, past concussions, and pre-existing mental and/or medical conditions.
The GSC tested the players by ranking 17 symptoms associated with concussion on a scale of 0 to 6, with 0 meaning the symptom wasn’t present and 6 meaning that it was the most severe form of the symptom. These symptoms include: headaches, nausea, dizziness, fatigue, difficulty sleeping, light or noise sensitivity, blurred vision, and memory issues. By scoring these symptoms, they could assess the player’s concussion on a scale.
Trainers tested players using the GSC at certain time points: the time of the injury, 3 hours after the injury, and 1, 2, 3, 5, and 7 days after the injury.
Guskiewicz and his team observed 196 concussions among 184 players, meaning 12 concussion were repeat. Of the 196 concussions, over half of the concussions occurred in practice. However, players were more likely to sustain a concussion during a game. Guskiewicz found that players from Division III schools were more likely to sustain a concussion than those from Divisions I and II. Offensive linemen, linebackers and defensive backs sustained concussions more than other positions in football.
Players reported on the GSC and the most common symptoms were headaches, dizziness and a feeling of being “slowed down”.
167 players who reported a headache at the time of the injury. 149 of them reported the headache 3 hours after the injury. 110 players reported a headache 24 hours after. 41 reported a headache 5 days after the injury and 23 players reported headaches 7 days after.
Of these players, he found that those who sustained a concussion in the past were 3 times more likely to get another concussion than those who had never suffered a concussion.
Guskiewicz found that those who had concussions in the past, or those who had one within the same season recovered at a slower pace than the players who got a concussion for the first time.
Source
Guskiewicz, K. et al, (2003). Cumulative Effects Associated with Recurrent Concussion in Collegiate Football Players, JAMA. 290(19), 2549–2555. doi:10.1001/jama.290.19.2549.
