Even mild traumatic brain injury may cause brain damage and thinking and memory problems, a new study by Newcastle University academics has found.

For the study, published today in the journal Neurology, the medical journal of the American Academy of Neurology, 44 people with a mild traumatic brain injury and nine people with a moderate traumatic brain injury were compared to 33 people with no brain injury.

Patients, who had all been treated by the Newcastle upon Tyne Hospitals NHS Foundation Trust, had suffered various accidents. These included; falling from bicycles with no helmet, falling from ladders doing jobs around the home, slipping and falling while just going about their daily life, being involved in motor vehicle accidents or being assaulted. They needed hospital attention but were treated and discharged either on the day of their injury or following a few days of observation and treatment in hospital. 

All participants were tested on their thinking and memory skills. At the same time, they had diffusion tensor imaging scans, a type of MRI scan that is better at detecting damage to brain cells and helps map fibre tracts that connect brain regions. The people with brain injuries had their scans an average of six days after they suffered the injury. A year later, 23 of those with injuries had another scan and took the cognitive tests again.

Compared to the people with no brain injury, those with injuries had damage to white brain matter which consisted of disruption to nerve axons, those parts of nerve cells that allow brain cells to transmit messages to each other.

The study found that patient scores on the verbal letter fluency task, a test of thinking and memory skills, were 25% lower than in the healthy people. This was strongly related to the imaging measures of white matter damage.

“Most of the studies thus far have focused on people with severe and chronic traumatic brain injury,” said study author Professor Andrew Blamire (pictured), of Newcastle University. “We studied patients who had suffered clinically mild injuries so this finding is especially important, as 90% of all traumatic brain injuries are mild to moderate.”

One year after the injury, the scores on thinking and memory tests were the same for people with brain injuries and those with no injuries, but there were still areas of brain damage in people with injuries.

“These results show that thinking skills were recovering over time,” Blamire said. “The areas of brain damage were not as widespread across the brain as previously, which could indicate that the brain was compensating for the injuries.”

The study was supported by the Sir Jules Thorn Charitable Trust. 

To learn more about traumatic brain injury, please visit www.aan.com/patients. 

published on: 17 July 2014