Concussion Damage Looks Like Early Alzheimer's: Study
Preliminary finding suggests mild brain injury triggers long-lasting abnormalities in white matter
These abnormalities could spark a series of reactions that lead to long-term problems with thinking and memory. "The cascade is what is the important factor," Alhilali said. "It doesn't appear what you're symptomatic from is the injury itself. What you're symptomatic from is how the brain responds to that injury."
However, brain experts believe that researchers may be going too far in trying to draw a link between the concussion damage they found and the chronic damage found in Alzheimer's.
"It's an interesting observation, but I think they are making a leap that the pattern of changes they see on the scan are indicative of what we see in Alzheimer's disease," said Dr. Ron Petersen, director of the Mayo Alzheimer's Disease Research Center. "Their correlation between the scores on the concussion instrument and white matter changes, that's nice and good and makes sense. But then they go into a rather extensive anatomical explanation of how this might be similar to Alzheimer's disease, and I find that a bit tenuous."
Podell listed a number of concerns with the article, including:
- The researchers' reliance on existing brain scans and symptom charts created by other people. "You don't know what questions were asked, who asked the questions, how they were asked," he said. "There are a lot of things you can't control for."
- The inclusion of young patients in the pool of subjects, who ranged in age from 10 to 38. "White matter is not fully developed in people until they are adults," he said. "You have 10-year-olds in this study. It is highly, highly unusual to mix young kids with adults, because the brain is so different."
- The use of sleep disturbance as a comparable symptom between concussion and Alzheimer's. "What's a common co-injury in concussion? Whiplash. You have neck pain, back pain," he said. "If you go to sleep, you don't think that pain wakes you up?"
"The issue is, does a single concussion in an individual mean they are at risk for developing Alzheimer's?" Podell said. "There are so many other factors involved, including genetic factors, management of a concussion and the general health and well-being of the individual throughout their life."
The study authors agreed that their findings are tentative.
"This is not a definitive study. This is not the end at all. This is the first step," Alhilali said. "We hope this will lead to more research that will further explore this potential link."
The researchers do believe their findings could lead to better treatments in the future, however.
"The first step in developing a treatment for any disease is understanding what causes it," Fakhran said. "If we can prove a link, or even a common pathway, between mild traumatic brain injury and Alzheimer's, this could potentially lead to treatment strategies that would be potentially efficacious in treating both diseases."