New research shows a correlation between poor sleep in TBI patients and elevated markers of neuronal injury.
By Lisa Spear
Could treating sleep disorders in traumatic brain injury patients lead to fewer cases of neurodegenerative disease down the road in this population?
The answer to this question has not yet been determined, but new research shows that this hypothesis is worth exploring further. A recent abstract reveals elevated markers of neuronal injury and cognitive deficits accompanying sleep complaints and obstructive sleep apnea risk in veterans with traumatic brain injury. According to the authors, this possibly identifies treatable pathophysiological mediators for traumatic neurodegenerative progression, but further research is needed to confirm this theory.
“If sleep is related, certainly that would be a good target for intervention to prevent progression,” says author neurologist and neuroscientist Kent Werner, MD, PhD.
The American Academy of Sleep Medicine (AASM) honored Werner for his work with the 2020 Trainee Investigator Award, which recognizes exceptional scientific discovery in the field of sleep medicine.
“I do want to thank the AASM. I think they deserve recognition for taking the time to encourage junior researchers to get out there,” says Werner, an assistant professor in the department of neurology at the Uniformed Services University of Health Sciences in Bethesda, Md.
The award-winning research, Werner says, came out of his curiosity. He wondered if the poor sleepers in the traumatic brain injury population had any evidence of worse neuronal injury or higher levels of the neuronal injury markers in their blood compared to the normal sleepers. They looked at a group of about 180 brain injury patients and categorized them into “good” and “bad” sleepers based on their Pittsburgh Sleep Quality Index score.
“The interesting thing that we found is that if you looked at the good sleepers compared to the bad sleepers, overall the bad sleepers have higher levels of this marker of neural injury called ‘neurofilament light,’” he says. “The more nerve damage that you have, the more neurodegenerative progression that you have, the more neurofilament light that you have; so it was interesting to see that these guys had higher levels.”
In fact, both their blood levels of the protein called tau, which is another breakdown product of nerves, and their levels of neurofilament light had a correlation with their poor quality of sleep.
“So the worse their sleep, the more nerve degeneration they appeared to have,” says Werner, who treats patients with sleep and related neurological disorders at the Walter Reed National Military Medical Center.
Any kind of synaptic activity in the brain will generate some byproducts. These byproducts can be normal. But when they are not cleared from the brain during sleep, they build up and are thought to cause neurodegenerative disease, which is prevalent in war veterans with traumatic brain injury.
“Sleep disorders in general are largely underdiagnosed and in the [traumatic brain injury] population that is even more of a problem. We can imagine there are so many of these guys that are bouncing around the system, getting seen for all their other problems, but never addressing the sleep issues and that may be a major contributor,” says Werner.
Lisa Spear is associate editor of Sleep Review.
Werner K, Shahim P, Gill J, et al. Poor sleep quality predicts serum markers of neurodegeneration and cognitive deficits in warriors with mild traumatic brain injury. Sleep. April 2020; 43(suppl_1): A159.
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