Single concussion may damage brain: study

A single concussion may cause lasting structural damage to the brain, a new study has warned.
"This is the first study that shows brain areas undergo measurable volume loss after concussion. In some patients, there are structural changes to the brain after a single concussive episode," said Yvonne W Lui, Neuroradiology section chief and assistant professor of radiology at NYU Langone School of Medicine in New York.
Following a concussion, some patients experience a brief loss of consciousness. Other symptoms include headache, dizziness, memory loss, attention deficit, depression and anxiety. Some of these conditions may persist for months or even years.

Lui and colleagues set out to investigate changes in global and regional brain volume in patients one year after Mild traumatic brain injury (MTBI).
Twenty-eight MTBI patients (with 19 followed at one year) with post-traumatic symptoms after injury and 22 matched controls (with 12 followed at one year) were enrolled in the study.
The researchers used three-dimensional magnetic resonance imaging (MRI) to determine regional gray matter and white matter volumes and correlated these findings with other clinical and cognitive measurements.

The researchers found that at one year after concussion, there was measurable global and regional brain atrophy in the MTBI patients. These findings show that brain atrophy is not exclusive to more severe brain injuries but can occur after a single concussion.

"This study confirms what we have long suspected. After MTBI, there is true structural injury to the brain, even though we don't see much on routine clinical imaging. This means that patients who are symptomatic in the long-term after a concussion may have a biologic underpinning of their symptoms," Lui said in a statement.
Certain brain regions showed a significant decrease in regional volume in patients with MTBI over the first year after injury, compared to controls. These volume changes correlated with cognitive changes in memory, attention and anxiety.
"Two of the brain regions affected were the anterior cingulate and the precuneal region," Lui said.

"The anterior cingulate has been implicated in mood disorders including depression, and the precuneal region has a lot of different connections to areas of the brain responsible for executive function or higher order thinking," she added.
The study was published in the journal Radiology.