Even a single concussion
appears to cause changes in the structure of the brain that may make cognitive problems and depression a higher likelihood, a new study shows.
The study, which used magnetic resonance imaging to compare healthy subjects' brains with those of patients a year after a mild traumatic brain injury, indicated that those with such injuries had shrinkage in brain regions that are key to memory, executive function and mood regulation.
The study, published online in the journal Radiology, is the first to show that even a single concussion
can leave measurable scars on the brain.
It used three-dimensional MRI scanning to measure the brain volume of 28 recent concussion
victims and 22 matched controls. A year later, researchers conducted the same scans of 19 patients with mild traumatic brain injuries and 12 of a healthy control group. Although the atrophy in the brains of the concussion
victims was "global" - it affected the brain's overall volume - it was particularly pronounced in the anterior cingulate and the precuneal region.
The anterior cingulate appears to serve as a switchboard for connecting the areas of the brain that are crucial to memory, attention, judgment and higher-order reasoning. Altered activity in the precuneus has been linked to depression, anxiety and post-traumatic stress disorder.
"This study confirms what we have long suspected," said the study's lead author, Dr. Yvonne W. Lui.
Lui is the neuroradiology chief at New York University's Langone Medical Center.
After a mild traumatic brain injury, "there is true structural injury to the brain, even though we don't see much on routine clinical imaging," she said.
For all of the increased focus the injury is getting, concussions
remain mysterious to physicians: Patients who never lose consciousness may suffer a life-threatening crisis of bleeding in the brain, or have lasting cognitive problems.