Second impact syndrome is a very rare condition in which a second concussion occurs before a first concussion has properly healed, causing rapid and severe brain swelling and often catastrophic results. Second impact syndrome can result from even a very mild concussion that occurs days or weeks after the initial concussion.
Populations at Risk for Second Impact Syndrome
Most cases of second impact syndrome have occurred in young athletes, particularly those who participate in sports such as boxing, baseball, football, hockey, and skiing. That’s why if an athlete has suffered a concussion, it’s best if they don’t return to their sport until the symptoms of the initial head injury are gone.
Symptoms of Second Impact Syndrome
Second impact injury can result within a matter of days or weeks, or it can occur in the same game or competition if the athlete isn’t removed and treated after the first concussion. Neither impact has to be severe for second impact syndrome to occur. Symptoms usually occur immediately following the second impact and progress rapidly. Common symptoms include:
- Dilated pupils
- Loss of eye movement
- Respiratory failure
Prognosis of Second Impact Syndrome
In many cases, second impact syndrome is fatal. In those cases where it isn’t fatal, you can expect the long-term effects to be similar to those of severe traumatic brain injury.