The study was done with the mouse model as the human analog, however its results could lead researchers down the path of what most believe about multiple insults to the brain;
We did it in mice. We gave them one mild concussion, so mild that they had no problems with learning or memory afterwards and then did it over and over and over again,” said Meehan, the study’s first author.
The mice were then tested for learning and memory, using what’s called a Morris water maze.
“Under the surface of the water is a hidden platform. And every time the mice find that platform, we reward them,” said Meehan. “The mice that are uninjured, have not been concussed, find that platform within five seconds after they do it several times. But mice that are injured take 20 to 25 seconds.”
And with each concussion, Meehan said it just got worse.
“Once they’ve had three concussions, or five, or 10, they develop profound deficits in their ability to learn and in their memory. And of course, mice don’t use steroids, and they don’t abuse drugs and alcohol,” said Meehan
The study appears in Neurosurgery and highlights not only the compounding effects of multiple traumas but takes out the other “factors” some seem to be grasping at for a reason as to why the brain is suffering. While we are looking at the text, it seems as though even a “mild” concussion is not so mild over time. Exactly what we have been saying for ever around here.
The abstract can be found HERE;
Increasing Recovery Time Between Injuries Improves Cognitive Outcome After Repetitive Mild Concussive Brain Injuries in Mice
Meehan, William P. III MD; Zhang, Jimmy BA; Mannix, Rebekah MD, MPH; Whalen, Michael J. MD
Conclusion: When delivered within a period of vulnerability, the cognitive effects of multiple concussions are cumulative, persistent, and may be permanent. Increasing the time interval between concussions attenuates the effects on cognition. When multiple concussions are sustained by mice daily, the effects on cognition are long-term.
Obviously there is not an “apples-to-apples” comparison from mice to humans, but it gives us a glimpse as to what may be occurring on a small scale. It will be difficult to get the smoking gun in humans unless there is a perfectly designed study; which is difficult at best being that this injury is subjective in nature.
Regardless, its once again evidence that not properly taking care of the injury from the beginning is harmful to your brain health going forward.