Even a mild blast to the brain can cause long-term, life-changing health problems, says Riyi Shi, professor of neuroscience and biomedical engineering at Purdue University in Lafayette, Indiana. However, the effects can be subtle: “The individual appears to be fine, and it’s difficult to tell if you just look at a person. But the fact is that these types of hits are multiplied over years and often ignored until someone reaches an age when other factors come into play.”
Treating the incidents sooner can help mitigate later-life issues, such as Parkinson disease (PD). Shi led a study that found checking the urine within 7 days following a blast incident—even a mild one—provides faster diagnosis when brain injury is suspected.
A simple urine analysis reveals elevations in the neurotoxin acrolein, Shi says, which is a biomarker for brain injury. In the study, the researchers evaluated the changes of α-synuclein and tyrosine hydroxylase, hallmarks of PD, and acrolein, a marker of oxidative stress. The researchers say in animal models of PD and traumatic brain injury (TBI), acrolein is “likely a point of pathogenic convergence.”
They found that after a single mild blast TBI, acrolein was elevated for up to a week, systemically in urine, and in whole brain tissue, specifically the substantia nigra and striatum. The elevation was accompanied by heightened α-synuclein oligomerization, dopaminergic dysregulation, and acrolein/α-synuclein interaction in the same brain regions. Taken together, the researchers say, the data suggest that acrolein likely plays a key role in inducing PD following blast TBI.
The presence of the biomarker “alerts us to the injury, creating an opportunity for intervention,” Shi says. “This early detection and subsequent treatment window could offer tremendous benefits for long-term patient neurologic health.”