Damage from concussions and the progressive deterioration of neurons in Alzheimer’s look similar on brain scans, according to the latest study, and produce similar symptoms as well.
In studying a group of concussions patients to determine which ones experienced the most severe symptoms, researchers from the University of Pittsburgh School of Medicine report that those who experienced mild traumatic brain injury after a blow to the head or a fall had brains that looked similar to those of Alzheimer’s patients. Previous studies have documented changes in the brain resulting from trauma to the head, and some analyses have associated concussions with a higher risk of learning problems, depression and early death.
The latest study, published in the journal of Radiology, looked at 64 patients who experienced concussions and compared their MRI brain scans a year after their injury to those of 15 healthy patients over the same time period. The images picked up white matter, which is made up of nerves and their protective coating, myelin, which facilitates connections between nerves in different regions of the brain. Networks of these nerves are responsible for cognitive functions such as memory, planning and reasoning. The scans revealed that the damage to the white matter in the concussion patients was similar to that of Alzheimer’s patients, whose nerves gradually died after being strangled by expanding plaques of amyloid proteins.
The study also showed that concussion patients suffered from the same sleep-wake disturbances that plague Alzheimer’s patients. These problems tend to make other cognitive issues, such as memory lapses and changes in behavior, worse. Both groups of patients also complained of being distracted by white noise, a common result of dysfunctional white matter that makes it increasingly difficult to filter irrelevant sounds and concentrate on specific ones.
“When we sleep, the brain organizes our experiences into memories, storing them so that we can later find them. The parahippocampus is important for this process, and involvement of the parahippocampus may, in part, explain the memory problems that occur in many patients after concussion,” says study author Dr. Saeed Fakhran, an assistant professor of radiology in the Division of Neuroradiology at the University of Pittsburgh in a statement.
The connection between concussions and Alzheimer’s pathology could lead to better understanding of how concussions affect the brain over time. The similarity to Alzheimer’s nerve damage, for example, suggests that the damage caused by the initial trauma continues to spur other harmful changes, just as they do in Alzheimer’s. “Our preliminary findings suggest that the initial traumatic event that caused the concussion acts as a trigger for a sequence of degenerative changes in the brain that results in patient symptoms and that may be potentially prevented. Furthermore, these neurodegenerative changes are very similar to those seen in early Alzheimer’s dementia,” says Fakhran.
That doesn’t mean that every concussion patient will develop Alzheimer’s but the growing body of knowledge in each field could lead to improvements in diagnosing and treating both conditions. Recognizing that brain injury from concussions, for example, progresses long after the trauma, could heighten efforts to protect athletes at high risk of concussions from getting injured in the first place.