Traumatic brain injury (TBI) is a common cause of death and disability worldwide. Research suggests that even a mild TBI – also called a concussion – can cause long-term damage to important brain structures, potentially impeding an individual’s ability to recover from the physical and cognitive symptoms associated with TBI. These post-concussive symptoms often include depression, anxiety, headache, and insomnia, all of which can significantly decrease quality of life.
Current research suggests that these symptoms may be related to cortical thinning, a reduction in the size and thickness of the layer of gray matter that encloses the brain. Although cortical thinning can occur during the course of normal aging, this phenomenon has also been discovered in people with mild TBI, suggesting that abnormal changes in cortical thickness may be related to injury.
An American research team sought to investigate the relationship between normal, age-related cortical thinning and cortical thinning as a result of mild TBI. They administered brain imaging scans to 66 U.S. service members with a history of TBI and 67 non-injured control participants. Using these images, the researchers measured each participant’s cortical thickness. They found that older participants showed a higher degree of cortical thinning than younger patients, which confirmed the previous finding that cortical thinning can occur naturally during the aging process. They also found that older adults with mild TBI showed a higher degree of cortical thinning than age-matched control participants, suggesting that TBI can accelerate age-related cortical thinning.
Some changes to brain structure should be expected during the natural aging process. However, normal cortical thinning can be significantly accelerated by mild TBI and may be partially responsible for the ongoing physical and neurological symptoms that many people experience after sustaining a concussion. Because elderly populations (65 years and older) are at increased risk of sustaining TBI, they are also at high risk of experiencing accelerated cortical thinning. Clinicians are advised to monitor older TBI patients for signs of brain structure abnormalities, even when the injury is mild.
Santhanam P, Wilson SH, & Oakes TR. Accelerated age-related cortical thinning in mild traumatic brain injury. Brain and Behavior. (November 2018).