Whether on the battlefield or playing field, trauma to the head has increasingly been shown to cause long-term damage to the brain.
Now, an OMRF scientist has completed a research project examining how traumatic brain injury (TBI) relates to degenerative brain disease. Specifically, OMRF’s Holly Van Remmen, Ph.D., and her colleagues looked at whether TBI affected disease progression in amyotrophic lateral sclerosis or ALS, better known as Lou Gehrig’s disease. There is evidence to suggest that TBI can increase the risk of ALS.
ALS is a progressive neurodegenerative disease affecting nerve cells in the brain and the spinal cord. As the nerve cells degenerate and die, it adversely affects the ability of the nervous system to control muscle movement, leading to paralysis and muscle wasting.
About 5,600 people in the U.S. are diagnosed with the disease each year. Patients live, on average, between two to five years from the time of diagnosis, and a cure has been very elusive.
“We were interested in learning if TBI would accelerate the progression of ALS in a well-characterized mouse model engineered to develop ALS,” said Van Remmen, who served as principal investigator on the project.
Van Remmen’s research team found that the mice with genetically induced ALS exposed to mild TBI had decreased coordination, muscle function and loss of grip strength, which points to evidence of a loss of natural reflexes. “Overall it only showed a few minor effects, but there were effects nonetheless,” she said.
According to Van Remmen, the loss of nerve supply to the muscles, which ultimately leads to the degeneration of cells, tends to be elevated when TBI is involved, as well. While the observable effects were minor, they can add to what is already a devastating condition.
“This research does not answer the question of whether suffering a traumatic brain injury can make you more likely to develop ALS, but it shows that the TBI can worsen the traits of ALS,” said Van Remmen.
It is possible, she said, that a more forceful head injury mimicking that seen in combat victims would yield more substantial progression in this already dramatic disease.
“This study represents the first time I think that anyone has shown changes in motor performance after TBI in mice with ALS,” said Van Remmen. “It reveals maybe that there is some measurable relationship between ALS and TBI.”
TBI contributes to nearly 30 percent of all injury deaths in the U.S. and results in approximately 2.5 million emergency room visits annually, according to the Centers for Disease Control and Prevention. Long-term effects of TBI can include memory loss, impaired coordination, loss of balance, impaired senses and serious emotional conditions such as aggression, anxiety and depression.
The new research was published in the journal Neuroscience. The research was funded in part by the Ruth L. Kirschstein National Research Service Award (NRSA) Individual Fellowship Grant (1F31NS080508-01), which was awarded to the paper’s first author, Teresa Evans, at the UT Health Science Center in San Antonio, as well as a VA merit grant for Van Remmen.