Traumatic brain injuries (TBIs) affect tens of thousands of Australians, mostly young males, every year.
Tragically, a number of these will result in death or permanent disability. But for most, the injury is considered mild. Within this “mild” group however, a small number continue to suffer debilitating effects for many years, long after others in similar circumstances have recovered. Reasons for this have been a mystery for quite some time. Are existing brain injury assessment techniques failing to identify hidden damage? An exciting new imaging technique being researched at the University of Adelaide is helping to reveal the answer. Called “Diffusion Tensor Imaging” (DTI), the unique non-invasive technique is a variation of existing Magnetic Resonance Imaging (MRI) technology and has been utilised by the University’s Adelaide Centre for Neuroscience Research.
According to project leader Professor Jane Mathias of the School of Psychology, it allows a clearer picture to be gained of the microstructure of the brain’s white matter. “We can now more accurately and reliably delineate neural pathways in healthy white matter, and in turn use this technology to identify subtle disruptions to those pathways as a result of mild TBIs,” she said. This important advance promises to help explain why people with outwardly similar mild TBIs – whether sustained through a motor vehicle accident, sporting injury, assault, or workplace or accidental injury – can experience different cognitive, psychological and physical effects, to varying degrees and over different timeframes. “We’re investigating this, along with the influence of several other possible contributing factors that may either increase the impact of an injury or help to protect a person against its effects,” said Professor Mathias. “These include the severity and cause of an injury, the site and side of impact, the influence of alcohol, genetic differences that may affect the physiological effects of an injury and pre-injury levels of functionality.”
The team is comparing five test groups. Three have had a TBI – one “mild”, another “moderate” and the third “severe”. A fourth group is composed of people who’ve had another type of injury not involving the head, such as a broken leg, and the final group is injury-free. “Each person completed a series of cognitive tasks and questionnaires, had a DTI brain scan, and provided a sample of saliva for genetic testing,” said Professor Mathias. “A subset also underwent the same procedures a year later so we could see what, if any, changes had occurred. The results are now in and we’re assessing the extent to which each of these factors, including any subtle differences in neural pathways revealed by DTI, can explain the varying functional deficits experienced by mild-TBI patients.” The next step is to identify some of the factors that increase the risk of a person having a poor outcome, and to use this information to improve the treatment, rehabilitation and quality of life of these people.