Concussion Damage Looks Like Early Alzheimer's: Study
Preliminary finding suggests mild brain injury triggers long-lasting abnormalities in white matter
The investigators then compared these brain scans to symptoms reported by concussed patients in a post-concussion questionnaire. They focused on symptoms shared with Alzheimer's patients, including memory problems, disturbances in sleep cycles and hearing problems.
The results showed a significant correlation between high concussion symptom scores and reduced water movement in the parts of the brain's white matter related to auditory processing and sleep-wake disturbances. Further, the researchers said, the distribution of white matter abnormalities in mildly concussed patients resembled the distribution of abnormalities in people with Alzheimer's disease.
"Basically, it looks a lot like Alzheimer's," said study co-author Dr. Lea Alhilali, an assistant professor of radiology at the University of Pittsburgh School of Medicine. "You get the same distribution of damage in the way that Alzheimer's disease affects the brain."
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?"