The number of blast-induced traumatic brain injuries (TBIs) is climbing in Iraq and Afghanistan as a result of increased use of improvised explosive devices (IEDs). This rise is affecting both the military and local people. However, some cases of long-term brain damage are missed because patients show no obvious symptoms. A blood-based biomarker featured in a study published in the Journal of Neurotrauma may be the key to unlocking early diagnosis.
Brain damage in blast-induced TBI can be caused by the pressure wave from the explosion, as a result of the head being hit by or hitting objects, or as a combination of both. Diagnosis is usually from symptoms, but that can miss less severe injuries, which can still cause long-term problems, or through an MRI, which is expensive and not always available nearby.
The researchers looked at rats with blast-induced TBI, and found 5 miRNAs (short strands of genetic material). One of these, known as microRNA let-7i, was increased in both the rat's blood and cerebrospinal fluid as a direct result of the injury, and could be measured in as few as three hours.
This is a very early study, just looking at results in rats. But if it translates into humans, a blood-based biomarker could lead to a simple and non-invasive test, perhaps even one that could be used in the field. This process could help to pick out the injured, even when they show no symptoms, so they may receive extra monitoring and care.
- see the paper